Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2018	Feb. 15, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	MGIC INVESTMENT CORP
Entity Central Index Key	0000876437
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 3,900
Entity Common Stock, Shares Outstanding		355,636,284
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investment portfolio:
Fixed income, available-for-sale, at fair value (amortized cost, 2018 - $5,196,784; 2017 - $4,946,278)	$ 5,151,987	$ 4,983,315
Equity securities, at fair value	3,932
Equity securities, at fair value (cost, 2018 - $3,993; 2017 - $7,223)		7,246
Other invested assets, at cost	3,100	0
Total investment portfolio	5,159,019	4,990,561
Cash and cash equivalents	151,892	99,851
Restricted cash and cash equivalents	3,146	0
Accrued investment income	48,001	46,060
Reinsurance recoverable on loss reserves	33,328	48,474
Reinsurance recoverable on paid losses	2,948	3,872
Premiums receivable	55,090	54,045
Home office and equipment, net	51,734	44,936
Deferred insurance policy acquisition costs	17,888	18,841
Deferred income taxes, net	69,184	234,381
Other assets	85,572	78,478
Total assets	5,677,802	5,619,499
Liabilities:
Loss reserves	674,019	985,635
Unearned premiums	409,985	392,934
FHLB Advance	155,000	155,000
Senior notes	419,713	418,560
Convertible junior subordinated debentures	256,872	256,872
Other liabilities	180,322	255,972
Total liabilities	2,095,911	2,464,973
Contingencies
Shareholders' equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2018 - 371,353; 2017 - 370,567; outstanding 2018 - 355,371; 2017 - 370,567)	371,353	370,567
Paid-in capital	1,862,536	1,850,582
Treasury stock (shares at cost 2018 - 15,982)	(175,059)	0
Accumulated other comprehensive loss, net of tax	(124,214)	(43,783)
Retained earnings	1,647,275	977,160
Total shareholders' equity	3,581,891	3,154,526
Total liabilities and shareholders' equity	$ 5,677,802	$ 5,619,499

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Fixed income, amortized cost	$ 5,196,784	$ 4,946,278
Equity securities, cost	$ 3,993
Equity securities, cost		$ 7,223
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	371,353,000	370,567,000
Common stock, shares outstanding (in shares)	355,371,000	370,567,000
Treasury stock, shares at cost (in shares)	15,982,000	0

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premiums written:
Direct	$ 1,103,332	$ 1,121,776	$ 1,107,923
Assumed	271	1,905	1,053
Ceded	(111,341)	(125,726)	(133,885)
Net premiums written	992,262	997,955	975,091
Increase in unearned premiums	(17,100)	(63,208)	(49,865)
Net premiums earned	975,162	934,747	925,226
Investment income, net of expenses	141,331	120,871	110,666
Net realized investment (losses) gains	(1,353)	231	8,921
Other revenue	8,708	10,205	17,670
Total revenues	1,123,848	1,066,054	1,062,483
Losses and expenses:
Losses incurred, net	36,562	53,709	240,157
Amortization of deferred policy acquisition costs	11,932	11,111	9,646
Other underwriting and operating expenses, net	178,211	159,638	150,763
Interest expense	52,993	57,035	56,672
Loss on debt extinguishment	0	65	90,531
Total losses and expenses	279,698	281,558	547,769
Income before tax	844,150	784,496	514,714
Provision for income taxes	174,053	428,735	172,197
Net income	$ 670,097	$ 355,761	$ 342,517
Earnings per share:
Basic (in dollars per share)	$ 1.83	$ 0.98	$ 1.00
Diluted (in dollars per share)	$ 1.78	$ 0.95	$ 0.86
Weighted average common shares outstanding - basic (in shares)	365,406	362,380	342,890
Weighted average common shares outstanding - diluted (in shares)	386,078	394,766	431,992

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 27,314	$ 120,027	$ 118,622	$ 89,798	$ 670,097	$ 355,761	$ 342,517
Other comprehensive (loss) income, net of tax:
Change in unrealized investment gains and losses									(64,646)	47,547	(3,649)
Benefit plans adjustment									(15,767)	(5,839)	(9,620)
Foreign currency translation adjustment									0	31	(951)
Other comprehensive (loss) income, net of tax									(80,413)	41,739	(14,220)
Comprehensive income									$ 589,684	$ 397,500	$ 328,297

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common stock	Paid-in capital	Treasury stock	Accumulated other comprehensive loss	Retained earnings	ASU 2016-09 Paid-in capital	ASU 2016-09 Retained earnings	ASU 2016-01 Accumulated other comprehensive loss	ASU 2016-01 Retained earnings
Balance, beginning of year at Dec. 31, 2015		$ 340,097	$ 1,670,238	$ (3,362)	$ (60,880)	$ 290,047
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		18,313	113,146
Net common stock issued under share-based compensation plans		990	(6,020)
Reissuance of treasury stock, net under share-based compensation plans			(130)	130
Tax benefit from share-based compensation			67
Equity compensation			11,373
Reacquisition of convertible junior subordinated debentures-equity component			(6,337)
Purchases of common stock	$ (147,100)			(147,127)
Reissuance of treasury stock, net				0
Other comprehensive (loss) income	(14,220)				(14,220)
Net income	342,517					342,517
Balance, end of year at Dec. 31, 2016	2,548,842	359,400	1,782,337	(150,359)	(75,100)	632,564
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting standard update							$ 49	$ 153
Issuance of common stock		10,386	60,903
Net common stock issued under share-based compensation plans		781	(7,602)
Reissuance of treasury stock, net under share-based compensation plans			0	0
Equity compensation			14,895
Purchases of common stock				0
Reissuance of treasury stock, net				150,359		(21,740)
Other comprehensive (loss) income	41,739				41,739
Net income	355,761					355,761
Cumulative effect to reclassify certain tax effects from accumulated other comprehensive loss					(10,422)	10,422
Balance, end of year at Dec. 31, 2017	3,154,526	370,567	1,850,582	0	(43,783)	977,160
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting standard update					(18)				$ (18)	$ 18
Issuance of common stock		0	0
Net common stock issued under share-based compensation plans		786	(8,917)
Reissuance of treasury stock, net under share-based compensation plans			0	0
Equity compensation			20,871
Purchases of common stock				(175,059)
Reissuance of treasury stock, net				0
Other comprehensive (loss) income	(80,413)				(80,413)
Net income	670,097					670,097
Balance, end of year at Dec. 31, 2018	$ 3,581,891	$ 371,353	$ 1,862,536	$ (175,059)	$ (124,214)	$ 1,647,275

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 670,097	$ 355,761	$ 342,517
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and other amortization	58,215	64,430	61,342
Deferred tax expense	186,572	355,044	162,356
Net realized investment losses (gains)	1,353	(231)	(8,921)
Loss on debt extinguishment	0	65	90,531
Change in certain assets and liabilities:
Accrued investment income	(1,941)	(1,987)	(3,849)
Reinsurance recoverable on loss reserves	15,146	2,019	(6,006)
Reinsurance recoverable on paid losses	924	1,092	(1,645)
Premiums receivable	(1,045)	(1,653)	(3,923)
Deferred insurance policy acquisition costs	953	(1,082)	(2,518)
Profit commission receivable	(5,479)	(2,844)	(747)
Loss reserves	(311,616)	(453,178)	(454,589)
Unearned premiums	17,051	63,197	49,764
Return premium accrual	(22,900)	(25,400)	(18,800)
Current income taxes	(77,551)	51,296	4,941
Other, net	14,738	128	14,307
Net cash provided by operating activities	544,517	406,657	224,760
Cash flows from investing activities:
Purchases of investments	(1,459,473)	(1,293,695)	(1,363,583)
Proceeds from sales of investments	370,449	246,908	733,299
Proceeds from maturity of fixed income securities	785,175	759,212	547,444
Net increase in payables for securities	307	0	0
Additions to property and equipment	(14,238)	(16,066)	(10,552)
Net cash used in investing activities	(317,780)	(303,641)	(93,392)
Cash flows from financing activities:
Proceeds from revolving credit facility	0	150,000	0
Repayment of revolving credit facility	0	(150,000)	0
Proceeds from issuance of long-term debt	0	0	573,094
Purchase or repayment of convertible senior notes	0	(145,620)	(363,778)
Payment of original issue discount - convertible senior notes	0	(4,504)	(11,250)
Purchase of convertible junior subordinated debentures	0	0	(100,860)
Payment of original issue discount-convertible junior subordinated debentures	0	0	(41,540)
Cash portion of loss on debt extinguishment	0	0	(59,460)
Repurchase of common stock	(163,419)	0	(147,127)
Payment of debt issuance costs	0	(1,630)	(1,127)
Payment of withholding taxes related to share-based compensation net share settlement	(8,131)	(6,821)	(5,030)
Net cash used in financing activities	(171,550)	(158,575)	(157,078)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents	55,187	(55,559)	(25,710)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year	99,851	155,410	181,120
Cash and cash equivalents and restricted cash and cash equivalents at end of year	$ 155,038	$ 99,851	$ 155,410

Nature of Business

12 Months Ended

Dec. 31, 2018

Nature of Business [Abstract]

Nature of Business



NOTE 1		Nature of Business

MGIC Investment Corporation is a holding company which, through Mortgage Guaranty Insurance Corporation ("MGIC"), is principally engaged in the mortgage insurance business. We provide mortgage insurance to lenders throughout the United States and to government sponsored entities to protect against loss from defaults on low down payment residential mortgage loans. Primary mortgage insurance provides mortgage default protection on individual loans and covers unpaid loan principal, delinquent interest and certain expenses associated with the default and subsequent foreclosure or sale approved by us. Through certain non-insurance subsidiaries, we also provide various services for the mortgage finance industry, such as contract underwriting, analysis of loan originations and portfolios, and mortgage lead generation. MGIC Assurance Corporation ("MAC"), an insurance subsidiary of MGIC provides insurance for certain mortgages under Fannie Mae and Freddie Mac (the "GSEs") credit risk transfer programs and is a participant in the Fannie Mae Enterprise-Paid Mortgage Insurance program.

At December 31, 2018, our direct domestic primary insurance in force ("IIF") was $209.7 billion, which represents the principal balance in our records of all mortgage loans that we insure, and our direct domestic primary risk in force ("RIF") was $54.1 billion, which represents the IIF multiplied by the insurance coverage percentage.

Substantially all of our insurance written since 2008 has been for loans purchased by the GSEs. We operate under the Private Mortgage Insurer Eligibility Requirements ("PMIERs") of the GSEs that became effective December 31, 2015 and which have been amended from time to time. The financial requirements of the PMIERs require a mortgage insurer’s "Available Assets" (generally only the most liquid assets of an insurer) to equal or exceed its "Minimum Required Assets" (which are based on an insurer's book, calculated from tables of factors with several risk dimensions and subject to a floor amount). Based on our interpretation of the PMIERs, as of December 31, 2018, MGIC’s Available Assets are in excess of its Minimum Required Assets; and MGIC is in compliance with the financial requirements of the PMIERs and eligible to insure loans purchased by the GSEs.

Basis of Presentation

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of Presentation



NOTE 2		Basis of Presentation

BASIS OF PRESENTATION

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"), as codified in the Accounting Standards Codification ("ASC"). Our consolidated financial statements include the accounts of MGIC Investment Corporation and its majority-owned subsidiaries. Intercompany transactions and balances have been eliminated. In accordance with GAAP, we are required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. We have considered subsequent events through the date of this filing.

RECLASSIFICATIONS

Certain reclassifications to 2017 and 2016 amounts have been made in the accompanying consolidated financial statements to conform to the 2018 presentation. See Note 3 - "Significant Accounting Policies" for a discussion of our adoption of accounting guidance in 2018 that resulted in other reclassifications.

Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Significant Accounting Policies



NOTE 3		Significant Accounting Policies

CASH AND CASH EQUIVALENTS

We consider money market funds and investments with original maturities of three months or less to be cash equivalents.

RESTRICTED CASH AND CASH EQUIVALENTS

Restricted cash and cash equivalents consists of cash and money market funds held in trusts for the benefit of contractual counterparties under reinsurance agreements.

FAIR VALUE MEASUREMENTS

We carry certain financial instruments at fair value and disclose the fair value of all financial instruments. Our financial instruments carried at fair value are predominantly measured on a recurring basis. Financial instruments measured on a nonrecurring basis are subject to fair value adjustments only in certain circumstances (for example, when there is evidence of impairment).

The fair value of an asset or liability is defined as the price that would be received upon a sale of an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Fair value is based on quoted market prices or inputs, where available. If prices or quotes are not available, fair value is based on valuation models or other valuation techniques that consider relevant transaction characteristics (such as maturity) and use as inputs observable or unobservable market parameters including yield curves, interest rates, volatilities, equity or debt prices, foreign exchange rates and credit curves. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value, as described below.

Valuation process

We use independent pricing sources to determine the fair value of a substantial majority of our financial instruments, which primarily consist of assets in our investment portfolio, but also includes amounts included in cash and cash equivalents and restricted cash. A variety of inputs are used; in approximate order of priority, they are: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications.

Market indicators, industry and economic events are also considered. This information is evaluated using a multidimensional pricing model. This model combines all inputs to arrive at a value assigned to each security. Quality controls are performed by the independent pricing sources throughout this process, which include reviewing tolerance reports, trading information, data changes, and directional moves compared to market moves.

On a quarterly basis, we perform quality controls over values received from the pricing sources which also include reviewing tolerance reports, data changes, and directional moves compared to market moves. We have not made any adjustments to the prices obtained from the independent pricing sources.

Valuation hierarchy

A three-level valuation hierarchy has been established under GAAP for disclosure of fair value measurements. The valuation hierarchy is based on the transparency of inputs to the valuation of a financial instrument as of the measurement date. To determine the fair value of securities available-for-sale in Level 1 and Level 2 of the fair value hierarchy, independent pricing sources, as described in "Valuation process," have been utilized. One price is provided per security based on observable market data. To ensure securities are appropriately classified in the fair value hierarchy, we review the pricing techniques and methodologies of the independent pricing sources and believe that their policies adequately consider market activity, either based on specific transactions for the issue valued or based on modeling of securities with similar credit quality, duration, yield and structure that were recently traded.

The three levels are defined as follows.



è	Level 1	Quoted prices for identical instruments in active markets that we can access. Financial assets using Level 1 inputs primarily include U.S. Treasury securities, money market funds, and certain equity securities.
è	Level 2	Quoted prices for similar instruments in active markets that we can access; quoted prices for identical or similar instruments in markets that are not active; and inputs, other than quoted prices, that are observable in the marketplace for the instrument. The observable inputs are used in valuation models to calculate the fair value of the instruments. Financial assets using Level 2 inputs primarily include obligations of U.S. government corporations and agencies, corporate bonds, mortgage-backed securities, asset-backed securities, and most municipal bonds. The independent pricing sources used for our Level 2 investments vary by type of investment. See Note 6 - "Fair Value Measurements" for further information.
è	Level 3	Valuations derived from valuation techniques in which one or more significant inputs or value drivers are unobservable or, from par values due to restrictions on certain securities that require them to be redeemed or sold only to the security issuer at par value. The inputs used to derive the fair value of Level 3 securities reflect our own assumptions about the assumptions a market participant would use in pricing an asset or liability. Financial assets using Level 3 inputs include obligations of U.S. states and political subdivisions and certain equity securities (2017 only). Our non-financial assets that are classified as Level 3 securities consist of real estate acquired through claim settlement. The fair value of real estate acquired is the lower of our acquisition cost or a percentage of the appraised value. The percentage applied to the appraised value is based upon our historical sales experience adjusted for current trends.

INVESTMENTS

Fixed income securities. Our fixed income securities are classified as available-for-sale and are reported at fair value. The related unrealized investment gains or losses are, after considering the related tax expense or benefit, recognized as a component of accumulated other comprehensive income (loss) in shareholders' equity. Realized investment gains and losses on fixed income securities are reported in income based upon specific identification of securities sold. as well as any "other than temporary" impairments ("OTTI") recognized in earnings.

Equity securities. At December 31, 2017, equity securities were classified as available-for-sale and were reported at fair value, except for certain equity securities that were carried at cost, for which the amount reported approximated fair value. These equity securities carried at cost are reported as Other invested assets at December 31, 2018, as required under ASU 2016-01, discussed in "Recent Accounting and Reporting Developments" below. The updated guidance also requires, effective January 1, 2018, the periodic change in fair value of equity securities to be recognized as realized investment gains and losses. For periods prior, realized investment gains and losses on equity securities were a function of the difference between the amount received on the sale of an equity security and the equity security's cost basis, as well as any OTTI recognized in earnings.

Other invested assets. Other invested assets are carried at cost. These assets represent our investment in Federal Home Loan Bank of Chicago ("FHLB") stock, which due to restrictions, is required to be redeemed or sold only to the security issuer at par value.

Unrealized losses and OTTI

Each quarter we perform reviews of our investments in order to determine whether declines in fair value below amortized cost were considered other-than-temporary. In evaluating whether a decline in fair value is other-than-temporary, we consider several factors including, but not limited to:



è	our intent to sell the security or whether it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis;
è	the present value of the discounted cash flows we expect to collect compared to the amortized cost basis of the security;
è	extent and duration of the decline;
è	failure of the issuer to make scheduled interest or principal payments;
è	change in rating below investment grade; and
è	adverse conditions specifically related to the security, an industry, or a geographic area.

Based on our evaluation, we will record an OTTI adjustment on a security if we intend to sell the impaired security, if it is more likely than not that we will be required to sell the impaired security prior to recovery of its amortized cost basis, or if the present value of the discounted cash flows we expect to collect is less than the amortized cost basis of the security. If the fair value of a security is below its amortized cost at the time of our intent to sell, the security is classified as other-than-temporarily impaired and the full amount of the impairment is recognized as a loss in the statement of operations. Otherwise, when a security is considered to be other-than-temporarily impaired, the losses are separated into the portion of the loss that represents the credit loss and the portion that is due to other factors. The credit loss portion is recognized as a loss in the statement of operations, while the loss due to other factors is recognized in accumulated other comprehensive loss, net of taxes. A credit loss is determined to exist if the present value of the discounted cash flows, using the security’s original yield, expected to be collected from the security is less than the cost basis of the security.

HOME OFFICE AND EQUIPMENT

Home office and equipment is carried at cost net of depreciation. For financial reporting purposes, depreciation is determined on a straight-line basis for the home office and equipment over estimated lives ranging from 3 to 45 years. For income tax purposes, we use accelerated depreciation methods.

Home office and equipment is shown net of accumulated depreciation of $38.1 million, $33.9 million and $30.6 million as of December 31, 2018, 2017 and 2016, respectively. Depreciation expense for the years ended December 31, 2018, 2017 and 2016 was $6.0 million, $5.4 million and $4.6 million, respectively.

DEFERRED INSURANCE POLICY ACQUISITION COSTS

Costs directly associated with the successful acquisition of mortgage insurance business, consisting of employee compensation and other policy issuance and underwriting expenses, are initially deferred and reported as deferred insurance policy acquisition costs ("DAC"). The deferred costs are net of any ceding commissions received associated with our reinsurance agreements. For each underwriting year of business, these costs are amortized to income in proportion to estimated gross profits over the estimated life of the policies. We utilize anticipated investment income in our calculation. This includes accruing interest on the unamortized balance of DAC. The estimates for each underwriting year are reviewed quarterly and updated when necessary to reflect actual experience and any changes to key variables such as persistency or loss development.

LOSS RESERVES

Reserves are established for insurance losses and loss adjustment expenses ("LAE") when we receive notices of delinquency on insured mortgage loans. We consider a loan in default when it is two or more payments past due. Even though the accounting standard, ASC 944, regarding accounting and reporting by insurance entities specifically excludes mortgage insurance from its guidance relating to loss reserves, we establish loss reserves using the general principles contained in the insurance standard. However, consistent with industry standards for mortgage insurers, we do not establish loss reserves for future claims on insured loans which are not currently delinquent. Loss reserves are established by estimating the number of loans in our inventory of delinquent loans that will result in a claim payment, which is referred to as the claim rate, and further estimating the amount of the claim payment, which is referred to as claim severity. Our loss estimates are established based upon historical experience, including with rescissions of policies, curtailments of claims, and loan modification activity. Adjustments to reserve estimates are reflected in the financial statements in the years in which the adjustments are made. The liability for reinsurance assumed is based on information provided by the ceding companies.

Reserves are established for estimated losses from delinquencies occurring prior to the close of an accounting period on notices of delinquency not yet reported to us. These incurred but not reported ("IBNR") reserves are also established using estimated claim rates and claim severities.

Reserves are established for the estimated costs of settling claims, including legal and other expenses and general expenses of administering the claims settlement process. Reserves are ceded to reinsurers under our reinsurance agreements. (See Note 8 – “Loss Reserves” and Note 9 – “Reinsurance.”)

PREMIUM DEFICIENCY RESERVE

After our loss reserves are initially established, we perform premium deficiency tests using our best estimate assumptions as of the testing date. Premium deficiency reserves are established, if necessary, when the present value of expected future losses and expenses exceeds the present value of expected future premium and already established reserves. Products are grouped for premium deficiency testing purposes based on similarities in the way the products are acquired, serviced and measured for profitability.

REVENUE RECOGNITION

We write policies which are guaranteed renewable contracts at the insured's option on a monthly, single, or annual premium basis. We have no ability to reunderwrite or reprice these contracts. Premiums written on monthly premium policies are earned as coverage is provided. Premiums written on single premium policies and annual premium policies are initially deferred as unearned premium reserve and earned over the estimated policy life. Premiums written on policies covering more than one year are amortized over the policy life based on historical experience, which includes the anticipated incurred loss pattern. Premiums written on annual premium policies are earned on a monthly pro rata basis. When a policy is cancelled for a reason other than rescission or claim payment, all premium that is non-refundable is immediately earned. Any refundable premium is returned to the servicer or borrower. When a policy is cancelled due to rescission, all previously collected premium is returned to the servicer and when a policy is cancelled because a claim is paid, premium collected since the date of delinquency is returned. The liability associated with our estimate of premium to be returned is accrued for separately and included in "Other liabilities" on our consolidated balance sheets. Changes in this liability, and the actual return of premiums for all periods, affects premiums written and earned.

Fee income of our non-insurance subsidiaries is earned and recognized as the services are provided and the customer is obligated to pay. Fee income consists primarily of contract underwriting and related fee-based services provided to lenders and is included in “Other revenue” on the consolidated statements of operations.

INCOME TAXES

Deferred income taxes are provided under the liability method, which recognizes the future tax effects of temporary differences between amounts reported in the consolidated financial statements and the tax bases of these items. The estimated tax effects are computed at the enacted federal statutory income tax rate. Changes in tax laws, rates, regulations, and policies or the final determination of tax audits or examinations, could materially affect our estimates and can be significant to our operating results. We evaluate the realizability of the deferred tax assets based on the weight of all available positive and negative evidence. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that all or some portion of the deferred tax assets will not be realized.

The recognition of a tax position is determined using a two-step approach, a more-likely-than-not threshold for recognition and derecognition, and a measurement attribute that is the greatest amount of benefit that is cumulatively greater than 50% likely of being realized. When evaluating a tax position for recognition and measurement, we presume that the tax position will be examined by the relevant taxing authority that has full knowledge of all relevant information. We recognize interest accrued and penalties related to unrecognized tax benefits in our provision for income taxes. (See "Note 12 - Income Taxes.")

BENEFIT PLANS

We have a non-contributory defined benefit pension plan covering substantially all domestic employees, as well as a supplemental executive retirement plan. Retirement benefits are based on compensation and years of service. We recognize these retirement benefit costs over the period during which employees render the service that qualifies them for benefits. Our policy is to fund pension cost as required under the Employee Retirement Income Security Act of 1974.

We offer both medical and dental benefits for retired domestic employees, their eligible spouses and dependents until the retiree reaches the age of 65. Under the plan retirees pay a premium for these benefits. We accrue the estimated costs of retiree medical and dental benefits over the period during which employees render the service that qualifies them for benefits. (See Note 11 – “Benefit Plans.”)

REINSURANCE

Loss reserves and unearned premiums are reported before taking credit for amounts ceded under reinsurance agreements. Ceded loss reserves are reflected as "Reinsurance recoverable on loss reserves." Ceded unearned and prepaid reinsurance premiums are included in “Other assets.” Amounts due from reinsurers on paid claims are reflected as “Reinsurance recoverable on paid losses.” Ceded premiums payable are included in “Other liabilities.” Any profit commissions are included with “Premiums written – Ceded” and any ceding commissions are included with “Other underwriting and operating expenses, net.” We remain liable for all insurance ceded. (See Note 9 – “Reinsurance.”)

SHARE-BASED COMPENSATION

We have certain share-based compensation plans. Under the fair value method, compensation cost is measured at the grant date based on the fair value of the award and is recognized over the service period which generally corresponds to the vesting period. Awards under our plans generally vest over periods ranging from one to three years. (See Note 15 – “Share-based Compensation Plans.”)

EARNINGS PER SHARE

Basic earnings per share ("EPS") is calculated by dividing net income by the weighted average number of shares of common stock outstanding. The computation of basic EPS includes as "participating securities" an immaterial number of unvested share-based compensation awards that contain non-forfeitable rights to dividends or dividend equivalents, whether paid or unpaid, under the "two-class" method. Our participating securities are composed of vested restricted stock and restricted stock units ("RSUs") with non-forfeitable rights to dividends (of which none have been declared since the issuance of these participating securities).

Diluted EPS includes the components of basic EPS and also gives effect to dilutive common stock equivalents. We calculate diluted EPS using the treasury stock method and if-converted method. Under the treasury stock method, diluted EPS reflects the potential dilution that could occur if our unvested restricted stock units result in the issuance of common stock. Under the if-converted method, diluted EPS reflects the potential dilution that could occur if our convertible debt instruments result in the issuance of common stock. The determination of potentially issuable shares does not consider the satisfaction of the conversion requirements and the shares are included in the determination of diluted EPS as of the beginning of the period, if dilutive. In addition to our 9% Debentures, of which a portion remain outstanding, we previously had several convertible senior note debt issuances that could have resulted in contingently issuable shares and we considered each potential issuance of shares separately to reflect the maximum potential dilution for the period the debt issuances were outstanding.

For purposes of calculating basic and diluted EPS, vested restricted stock and RSUs are considered outstanding.

RELATED PARTY TRANSACTIONS

There were no related party transactions during 2018, 2017 or 2016.

RECENT ACCOUNTING AND REPORTING DEVELOPMENTS

Accounting standards effective in 2018, or early adopted, and relevant to our financial statements

Table 3.1 shows the relevant amendments to accounting standards that have been implemented for the fiscal year beginning January 1, 2018; none had a material impact on our consolidated financial statements or disclosures.



Standard / Interpretation
Table	3.1
				Effective date
Amended Standards
ASC 230		Statement of Cash Flows
		•	ASU 2016-18 - Restricted Cash	January 1, 2018
ASC 718		Compensation - Stock Compensation
		•	ASU 2017-09 - Scope of Modification Accounting	January 1, 2018
ASC 310		Receivables - Nonrefundable Fees and Other Costs
		•	ASU 2017-08 - Premium Amortization on Purchased Callable Debt Securities	January 1, 2019
ASC 715		Compensation - Retirement Benefits
		•	ASU 2017-07 - Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost	January 1, 2018
ASC 825		Financial Instruments - Overall
		•	ASU 2016-01 - Recognition and Measurement of Financial Assets and Financial Liabilities	January 1, 2018

Statement of Cash Flows - Restricted Cash

In November 2016, the Financial Accounting Standards Board ("FASB") issued updated guidance related to the presentation of restricted cash in the statement of cash flows. The updated guidance requires that the statement of cash flows explain the change during the period in total cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The updated guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods.



è	Adoption impact: The statements of cash flows presented for the three years ended December 31, 2018 are in accordance with the guidance of this updated standard.

Stock Compensation - Scope of Modification Accounting

In May 2017, the FASB issued updated guidance related to a change in the terms or conditions (modification) of a share-based award. The updated guidance provides that an entity should account for the effects of a modification unless the fair value and vesting conditions of the modified award and the classification of the award (equity or liability instrument) are the same as the original award immediately before the modification. The updated guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods.



è	Adoption impact: The adoption of this guidance had no impact on our consolidated financial statements or disclosures.

Premium Amortization on Purchased Callable Debt Securities

In March 2017, the FASB issued updated guidance to amend the amortization period for certain purchased callable debt securities held at a premium, shortening the amortization period to the earliest call date. This updated guidance aligns with how callable debt securities, in the United States, are generally quoted, priced, and traded, which incorporates consideration of calls (also referred to as “yield-to-worst” pricing). The updated guidance is effective for annual periods beginning after December 15, 2018, including interim periods within those annual periods, but allows for early adoption.



è	Adoption impact: We adopted this guidance as of January 1, 2018 with no impact to our consolidated financial statements or disclosures as our accounting policy adhered to the updated guidance.

Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost

In March 2017, the FASB issued updated guidance intended to improve the reporting of net benefit cost in the financial statements. The updated guidance requires that an employer report the service cost component of pension and post-retirement benefit costs in the same financial statement caption as other compensation costs arising from services rendered by employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside a subtotal of income from operations, if one is presented. Previous guidance did not prescribe where the amount of net benefit cost should be presented in an employer’s statement of operations and did not require entities to disclose by line item the amount of net benefit cost that is included in the statement of operations. The updated guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods.



è	Adoption impact: The adoption of this guidance had no impact on our consolidated financial statements or disclosures as the service cost component is reported in the same financial statement caption as other compensation costs and we do not present a subtotal of income outside of income from operations. The service cost component of our benefit plans is disclosed in Note 11 - “Benefit Plans” to our consolidated financial statements.

Recognition and Measurement of Financial Assets and Financial Liabilities

In January 2016, the FASB issued updated guidance to address the recognition, measurement, presentation, and disclosure of certain financial instruments. The updated guidance requires equity investments, except those accounted for under the equity method of accounting, that have a readily determinable fair value to be measured at fair value with changes in fair value recognized in net income. Equity investments that do not have readily determinable fair values may be remeasured at fair value either upon the occurrence of an observable price change or upon identification of an impairment. A qualitative assessment for impairment is required for equity investments without readily determinable fair values. The updated guidance also eliminates the requirement to disclose the method and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost on the balance sheet. Further, the updated guidance clarifies that entities should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entities’ other deferred tax assets. The updated guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods and requires recognition of a cumulative effect adjustment at adoption.



è	Adoption impact: The adoption of this guidance resulted in an immaterial cumulative effect adjustment to our 2018 beginning accumulated other comprehensive (loss) income and retained earnings to recognize unrealized gains on equity investments. At December 31, 2017, equity investments were classified as available-for-sale on the consolidated balance sheet. Upon adoption, the updated guidance eliminated the available-for-sale balance sheet classification for equity securities.

In February 2018, the FASB issued a separate update for technical corrections and improvements to clarify certain aspects of the guidance described above. This update clarifies the presentation of investments in, among other things, Federal Home Loan Bank stock and prohibits those investments from being shown with equity securities.



è	Adoption impact: At December 31, 2018, the value of our investment in FHLB stock, which is carried at cost, is presented within “Other invested assets” on our consolidated balance sheet.

PROSPECTIVE ACCOUNTING STANDARDS

Table 3.2 shows the relevant new amendments to accounting standards, which are not yet effective or adopted.



Standard / Interpretation
Table	3.2
				Effective date
Amended Standards
ASC 326		Financial Instruments - Credit Losses
		•	ASU 2016-13 - Measurement of Credit Losses on Financial Instruments	January 1, 2020
ASC 820		Fair Value Measurement
		•	ASU 2018-13 - Changes to the Disclosure Requirements for Fair Value Measurements	January 1, 2020
ASC 715		Compensation - Retirement Benefits
		•	ASU 2018-14 - Changes to the Disclosure Requirements for Defined Benefit Plans	January 1, 2021

Measurement of Credit Losses on Financial Instruments

In June 2016, the FASB issued updated guidance that requires immediate recognition of estimated credit losses expected to occur over the remaining life of many financial instruments. Entities will be required to utilize a current expected credit losses (“CECL”) methodology that incorporates their forecast of future economic conditions into their loss estimate unless such forecast is not reasonable and supportable, in which case the entity will revert to historical loss experience. Any allowance for CECL reduces the amortized cost basis of the financial instrument to the amount an entity expects to collect. Credit losses relating to available-for-sale fixed maturity securities are to be recorded through an allowance for credit losses, rather than a write-down of the asset, with the amount of the allowance limited to the amount by which fair value is less than amortized cost. In addition, the length of time a security has been in an unrealized loss position will no longer impact the determination of whether a credit loss exists. The updated guidance is not prescriptive about certain aspects of estimating expected credit losses, including the specific methodology to use, and therefore will require significant judgment in application. The updated guidance is effective for annual periods beginning after December 15, 2019, including interim periods within those annual periods. Early adoption is permitted for annual and interim periods in fiscal years beginning after December 15, 2018. We are currently evaluating the impacts the adoption of this guidance will have on our consolidated financial statements, but do not expect it to have a material impact on our consolidated financial statements or disclosures.

Changes to the Disclosure Requirements for Fair Value Measurement

In August 2018, the FASB issued updated guidance that changes the disclosure requirements for fair value measurements. The updated guidance removed the requirement to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; the policy for timing of transfers between levels; and the valuation processes for Level 3 fair value measurements. The updated guidance clarifies that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurements as of the reporting date. Further, the updated guidance will require disclosure of changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period; and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The updated guidance is effective for annual periods beginning after December 15, 2019, including interim periods within those annual periods. Early adoption was permitted upon issuance of this update. An entity is permitted to early adopt any guidance that removed or modified disclosures upon issuance of this update and to delay adoption of the additional disclosures until its effective date. We are currently evaluating the impacts the adoption of this guidance will have on our consolidated financial statement disclosures, but do not expect it to have a material impact.

Changes to the Disclosure Requirements for Defined Benefit Plans

In August 2018, the FASB issued amendments to modify the disclosure requirements for defined benefit plans. The updated guidance removed the requirements to identify amounts that are expected to be reclassified out of accumulated other comprehensive income and recognized as components of net periodic benefit cost in the coming year and the effects of a one-percentage-point change in assumed health care cost trend rates on service and interest cost and on the postretirement benefit obligation. The updated guidance added disclosures for the weighted-average interest crediting rates for cash balance plans and other plans with interest crediting rates and explanations for significant gains and losses related to changes in the benefit obligation for the period. The updated guidance is effective for annual periods beginning after December 15, 2020. Early adoption is permitted. An entity should apply the amendments on a retrospective basis to all periods presented. We are currently evaluating the impacts the adoption of this guidance will have on our consolidated financial statement disclosures, but do not expect it to have a material impact.

Earnings per Share

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Earnings per Share



NOTE 4		Earnings Per Share

Table 4.1 reconciles basic and diluted EPS amounts:



Earnings per share
Table	4.1
		Years Ended December 31,
(In thousands, except per share data)		2018		2017		2016
Basic earnings per share:
Net income		$	670,097	$	355,761	$	342,517
Weighted average common shares outstanding - basic		365,406		362,380		342,890
Basic earnings per share		$	1.83	$	0.98	$	1.00
Diluted earnings per share:
Net income		$	670,097	$	355,761	$	342,517
Interest expense, net of tax ⁽¹⁾:
2% Notes		—		907		6,111
5% Notes		—		1,709		6,362
9% Debentures		18,264		15,027		15,893
Diluted income available to common shareholders		$	688,361	$	373,404	$	370,883
Weighted-average shares - basic		365,406		362,380		342,890
Effect of dilutive securities:
Unvested restricted stock units		1,644		1,493		1,470
2% Notes		—		8,317		54,450
5% Notes		—		3,548		13,107
9% Debentures		19,028		19,028		20,075
Weighted average common shares outstanding - diluted		386,078		394,766		431,992
Diluted income per share		$	1.78	$	0.95	$	0.86


⁽¹⁾	Interest expense for the years ended December 31, 2018, 2017 and 2016 has been tax effected at a rate of 21%, 35%, and 35%, respectively.

For the years ended December 31, 2018, 2017, and 2016, all of our then outstanding Convertible Senior Notes and Convertible Junior Subordinated Debentures are reflected in diluted earnings per share using the “if-converted” method. Under this method, if dilutive, the common stock related to the outstanding Convertible Senior Notes and/or Convertible Junior Debentures is assumed issued as of the beginning of the reporting period and the related interest expense, net of tax, is added back to earnings in calculating diluted EPS.

Investments

12 Months Ended

Dec. 31, 2018

Investments [Abstract]

Investments



NOTE 5		Investments

FIXED INCOME SECURITIES

The amortized cost, gross unrealized gains and losses and fair value of our fixed income securities as of December 31, 2018 and 2017 are shown below:



Details of fixed income investment securities by category as of December 31, 2018
Table	5.1a
(In thousands)		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	167,655	$	597	$	(1,076	)	$	167,176
Obligations of U.S. states and political subdivisions		1,701,826		29,259		(10,985		)	1,720,100
Corporate debt securities		2,439,173		2,103		(40,514		)	2,400,762
ABS		111,953		226		(146		)	112,033
RMBS		189,238		32		(10,309		)	178,961
CMBS		276,352		888		(9,580		)	267,660
CLOs		310,587		2		(5,294		)	305,295
Total fixed income securities		$	5,196,784	$	33,107	$	(77,904	)	$	5,151,987



Details of fixed income investment securities by category as of December 31, 2017
Table	5.1b
(In thousands)		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	179,850	$	274	$	(1,278	)	$	178,846
Obligations of U.S. states and political subdivisions		2,105,063		56,210		(8,749		)	2,152,524
Corporate debt securities		2,065,475		10,532		(9,169		)	2,066,838
ABS		4,925		—		(2		)	4,923
RMBS		189,153		60		(7,364		)	181,849
CMBS		301,014		1,204		(4,906		)	297,312
CLOs		100,798		304		(79		)	101,023
Total fixed income securities		$	4,946,278	$	68,584	$	(31,547	)	$	4,983,315


⁽¹⁾	There were no OTTI losses recorded in other comprehensive (loss) income as of December 31, 2018 and 2017.

We had $13.5 million and $13.6 million of investments at fair value on deposit with various states as of December 31, 2018 and 2017, respectively, due to regulatory requirements of those state insurance departments. In connection with our insurance and reinsurance activities, we are required to maintain assets in trusts for the benefit of contractual counterparties. The fair value of the investments on deposit in these trusts was $26.3 million and $7.7 million at December 31, 2018 and 2017, respectively.

Table 5.2 compares the amortized cost and fair values of fixed income securities, by contractual maturity, as of December 31, 2018. The analysis is based upon contractual maturity. Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay certain obligations with or without call or prepayment penalties. Because most mortgage and asset-backed securities provide for periodic payments throughout their lives, they are listed separately in the table.



Fixed income securities maturity schedule
Table	5.2
		December 31, 2018
(In thousands)		Amortized Cost		Fair Value
Due in one year or less		$	484,485	$	482,919
Due after one year through five years		1,652,638		1,632,494
Due after five years through ten years		1,011,237		996,335
Due after ten years		1,160,294		1,176,290
		4,308,654		4,288,038

ABS		111,953		112,033
RMBS		189,238		178,961
CMBS		276,352		267,660
CLOs		310,587		305,295
Total as of December 31, 2018		$	5,196,784	$	5,151,987

Proceeds from the sale of fixed income securities classified as available-for-sale were $365.6 million, $246.9 million, and $728.0 million during the years ended December 31, 2018, 2017, and 2016, respectively. Gross gains of $0.7 million, $1.6 million, and $11.9 million and gross losses of $3.8 million, $1.4 million and $3.0 million were realized on those sales during the years ended December 31, 2018, 2017, and 2016, respectively.

For the year ended December 31, 2018, we recorded $1.8 million of OTTI losses in earnings. For the years ended December 31, 2017 and 2016, there were no OTTI losses in earnings.

EQUITY SECURITIES

The cost and fair value of investments in equity securities as of December 31, 2018 and December 31, 2017 are showing in tables 5.3a and 5.3b below. As described in Note 3 - "Significant Accounting Pronouncements," under updated guidance regarding the "Recognition and Measurement of Financial Assets and Financial Liabilities" which became effective on January 1, 2018, the amount of our FHLB stock investment has been reclassified and presented in "Other invested assets" on our consolidated balance sheet as of December 31, 2018.

Details of equity investment securities as of December 31, 2018

Table

5.3a

(In thousands)

Cost

Gross gains

Gross losses

Fair Value

Equity securities

3,993

(72

)

3,932

Details of equity investment securities as of December 31, 2017

Table

5.3b

(In thousands)

Cost

Gross gains

Gross losses

Fair Value

Equity securities

7,223

(16

)

7,246

Proceeds from the sale of equity securities were $4.9 million during the year ended December 31, 2018. Gross gains of $3.7 million were realized on those sales during the year ended December 31, 2018. There were no sales of equity securities in 2017 or 2016. For the year ended December 31, 2018, we recognized $84 thousand of net losses on equity securities still held as of December 31, 2018, which are reported in Net realized investment (losses) gains on our consolidated statements of operations.

OTHER INVESTED ASSETS

Other invested assets include an investment in FHLB stock that is carried at cost, which due to its nature approximates fair value. Ownership of FHLB stock provides access to a secured lending facility, and our current FHLB Advance amount is secured by eligible collateral whose fair value is maintained at a minimum of 102% of the outstanding principal balance of the FHLB Advance. As of December 31, 2018, that collateral consisted of fixed income securities included in our total investment portfolio, and cash and cash equivalents, with a total fair value of $168.9 million.

UNREALIZED INVESTMENT LOSSES

Tables 5.4a and 5.4b below summarize, for all available-for-sale investments in an unrealized loss position as of December 31, 2018 and 2017, the aggregate fair value and gross unrealized losses by the length of time those securities have been continuously in an unrealized loss position. Gross unrealized losses on our available-for-sale investments amounted to $78 million and $32 million as of December 31, 2018 and 2017, respectively. The fair value amounts reported in tables 5.4a and 5.4b below are estimated using the process described in Note 6 - "Fair Value Measurements" to these consolidated financial statements.



Unrealized loss aging for securities by type and length of time as of December 31, 2018
Table	5.4a
		Less Than 12 Months					12 Months or Greater					Total
(In thousands)		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	23,710	$	(15	)	$	69,146	$	(1,061	)	$	92,856	$	(1,076	)
Obligations of U.S. states and political subdivisions		316,655		(3,875		)	358,086		(7,110		)	674,741		(10,985		)
Corporate debt securities		1,272,279		(18,130		)	785,627		(22,384		)	2,057,906		(40,514		)
ABS		51,324		(146		)	—		—			51,324		(146		)
RMBS		24		—			178,573		(10,309		)	178,597		(10,309		)
CMBS		65,704		(1,060		)	163,272		(8,520		)	228,976		(9,580		)
CLOs		296,497		(5,294		)	—		—			296,497		(5,294		)
Total		$	2,026,193	$	(28,520	)	$	1,554,704	$	(49,384	)	$	3,580,897	$	(77,904	)



Unrealized loss aging for securities by type and length of time as of December 31, 2017
Table	5.4b
		Less Than 12 Months					12 Months or Greater					Total
(In thousands)		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	144,042	$	(796	)	$	31,196	$	(482	)	$	175,238	$	(1,278	)
Obligations of U.S. states and political subdivisions		505,311		(3,624		)	211,684		(5,125		)	716,995		(8,749		)
Corporate debt securities		932,350		(4,288		)	200,716		(4,881		)	1,133,066		(9,169		)
ABS		4,923		(2		)	—		—			4,923		(2		)
RMBS		14,979		(280		)	166,329		(7,084		)	181,308		(7,364		)
CMBS		51,096		(358		)	138,769		(4,548		)	189,865		(4,906		)
CLOs		14,243		(7		)	3,568		(72		)	17,811		(79		)
Equity securities		226		(2		)	431		(14		)	657		(16		)
Total		$	1,667,170	$	(9,357	)	$	752,693	$	(22,206	)	$	2,419,863	$	(31,563	)

For those securities in an unrealized loss position, the length of time the securities were in such a position, is measured by their month-end fair values. The unrealized losses in all categories of our investments as of December 31, 2018 and 2017 were primarily caused by changes in interest rates between the time of purchase and the respective year end. There were 721 and 586 securities in an unrealized loss position as of December 31, 2018 and 2017, respectively. As of December 31, 2018, the fair value as a percent of amortized cost of the securities in an unrealized loss position was 98% and approximately 8% of the securities in an unrealized loss position were backed by the U.S. Government.

The source of net investment income is shown in table 5.5 below.



Net investment income
Table	5.5
(In thousands)		2018			2017			2016
Fixed income securities		$	140,539		$	122,105		$	112,513
Equity securities		228			206			182
Cash equivalents		3,423			1,447			754
Other		816			620			433
Investment income		145,006			124,378			113,882
Investment expenses		(3,675		)	(3,507		)	(3,216		)
Net investment income		$	141,331		$	120,871		$	110,666

The change in unrealized gains (losses) of investments is shown in table 5.6 below.



Change in unrealized gains (losses)
Table	5.6
(In thousands)		2018			2017			2016
Fixed income securities		$	(81,834	)	$	69,026		$	(5,403	)
Equity securities		—			39			(36		)
Other		—			(13		)	14
Change in unrealized gains/losses		$	(81,834	)	$	69,052		$	(5,425	)

Fair Value Measurements

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements



NOTE 6		Fair Value Measurements

The following table describes the valuation methodologies generally used by the independent pricing sources, or by us, to measure financial instruments at fair value, including the general classification of such financial instruments pursuant to the valuation hierarchy.

Level 1 measurements


•	Fixed income securities: Consist of primarily U.S. Treasury securities with valuations derived from quoted prices for identical instruments in active markets that we can access.


•	Equity securities: Consist of actively traded, exchange-listed equity securities with valuations derived from quoted prices for identical assets in active markets that we can access.


•	Other: Consists of money market funds with valuations derived from quoted prices for identical assets in active markets that we can access.

Level 2 measurements


•	Fixed income securities:

Corporate Debt & U.S. Government and Agency Bonds are valued by surveying the dealer community, obtaining relevant trade data, benchmark quotes and spreads and incorporating this information into the valuation process.

Obligations of U.S. States & Political Subdivisions are valued by tracking, capturing, and analyzing quotes for active issues and trades reported via the Municipal Securities Rulemaking Board records. Daily briefings and reviews of current economic conditions, trading levels, spread relationships, and the slope of the yield curve provide further data for evaluation.

Residential Mortgage-Backed Securities ("RMBS") are valued by monitoring interest rate movements, and other pertinent data daily. Incoming market data is enriched to derive spread, yield and/or price data as appropriate, enabling known data points to be extrapolated for valuation application across a range of related securities.

Commercial Mortgage-Backed Securities ("CMBS") are valued using techniques that reflect market participants’ assumptions and maximize the use of relevant observable inputs including quoted prices for similar assets, benchmark yield curves and market corroborated inputs. Evaluation uses regular reviews of the inputs for securities covered, including executed trades, broker quotes, credit information, collateral attributes and/or cash flow waterfall as applicable.

Asset-Backed Securities ("ABS") are valued using spreads and other information solicited from market buy-and-sell-side sources, including primary and secondary dealers, portfolio managers, and research analysts. Cash flows are generated for each tranche, benchmark yields are determined, and deal collateral performance and tranche level attributes including trade activity, bids, and offers are applied, resulting in tranche specific prices.

Collateralized loan obligations ("CLO") Collateralized Loan Obligations are valued by evaluating manager rating, seniority in the capital structure, assumptions about prepayment, default and recovery and their impact on cash flow generation. Loan level net asset values are determined and aggregated for tranches and as a final step prices are checked against available recent trade activity.

Level 3 measurements


•	Equity securities (2017): FHLB stock valued at par value due to restrictions that require it to be redeemed or sold only to the security issuer at par value.

RECURRING FAIR VALUE MEASUREMENTS

Assets carried at fair value included those listed, by hierarchy level, in the following tables as of December 31, 2018 and 2017:



Assets carried at fair value by hierarchy level as of December 31, 2018
Table	6.1a
(In thousands)		Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	167,176	$	42,264	$	124,912	$	—
Obligations of U.S. states and political subdivisions		1,720,100		—		1,720,087		13
Corporate debt securities		2,400,762		—		2,400,762		—
ABS		112,033		—		112,033		—
RMBS		178,961		—		178,961		—
CMBS		267,660		—		267,660		—
CLOs		305,295		—		305,295		—
Total fixed income securities		5,151,987		42,264		5,109,710		13
Equity securities		3,932		3,932		—		—
Other ⁽¹⁾		96,403		96,403		—		—
Real estate acquired ⁽²⁾		14,535		—		—		14,535
Total		$	5,266,857	$	142,599	$	5,109,710	$	14,548



Assets carried at fair value by hierarchy level as of December 31, 2017
Table	6.1b
(In thousands)		Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	178,846	$	81,598	$	97,248	$	—
Obligations of U.S. states and political subdivisions		2,152,524		—		2,152,253		271
Corporate debt securities		2,066,838		—		2,066,838		—
ABS		4,923		—		4,923		—
RMBS		181,849		—		181,849		—
CMBS		297,312		—		297,312		—
CLOs		101,023		—		101,023		—
Total fixed income securities		4,983,315		81,598		4,901,446		271
Equity securities ⁽³⁾		7,246		2,978		—		4,268
Real estate acquired ⁽²⁾		12,713		—		—		12,713
Total		$	5,003,274	$	84,576	$	4,901,446	$	17,252


⁽¹⁾	Consists of money market funds included in "Cash and Cash Equivalents" and "Restricted Cash and Cash Equivalents" on the consolidated balance sheet.


⁽²⁾	Real estate acquired through claim settlement, which is held for sale, is reported in "Other assets" on the consolidated balance sheets.


⁽³⁾	Equity securities in Level 3 are carried at cost, which approximates fair value. See "Reconciliation of Level 3 assets" below for information regarding a change in presentation of amounts previously included in Level 3 Equity securities.

Certain financial instruments, including insurance contracts, are excluded from fair value disclosure requirements. The carrying values of cash and cash equivalents (Level 1) and accrued investment income (Level 2) approximated their fair values.

RECONCILIATIONS OF LEVEL 3 ASSETS

For assets and liabilities measured at fair value using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances for the years ended December 31, 2018, 2017, and 2016 is shown in tables 6.2a, 6.2b and 6.2c below. As described in Note 3 - "Significant Accounting Policies," under updated guidance regarding the "Recognition and Measurement of Financial Assets and Financial Liabilities" which became effective on January 1, 2018, our investment in FHLB stock is no longer presented with equity securities. Prior to the updated guidance, the FHLB stock was included in our Level 3 equity securities. As shown in table 6.2a below, for the year ended December 31, 2018, we have transferred the FHLB stock out of Level 3 assets, and it is carried at cost, which approximates fair value, on our consolidated balance sheet in "Other invested assets" as of December 31, 2018. There were no transfers into or out of Level 3 for the years ending December 31, 2017 and 2016. There were no losses included in earnings for the years ended December 31, 2018, 2017, and 2016 attributable to the change in unrealized losses on assets still held at the end of each applicable year.



Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2018
Table	6.2a
(In thousands)		Debt Securities			Equity Securities			Total Investments			Real Estate Acquired
Balance at December 31, 2017		$	271		$	4,268		$	4,539		$	12,713
Transfers out of Level 3		—			(3,100		)	(3,100		)	—
Total realized/unrealized gains (losses):
Included in earnings and reported as net realized investment gains		—			3,663			3,663			—
Included in earnings and reported as losses incurred, net		—			—			—			(1,995		)
Purchases		—			—			—			33,912
Sales		(258		)	(4,831		)	(5,089		)	(30,095		)
Balance at December 31, 2018		$	13		$	—		$	13		$	14,535



Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2017
Table	6.2b
(In thousands)		Debt Securities			Equity Securities		Total Investments			Real Estate Acquired
Balance at December 31, 2016		$	691		$	4,268	$	4,959		$	11,748
Total realized/unrealized gains (losses):
Included in earnings and reported as losses incurred, net		—			—		—			(1,315		)
Purchases		—			—		—			34,749
Sales		(420		)	—		(420		)	(32,469		)
Balance at December 31, 2017		$	271		$	4,268	$	4,539		$	12,713



Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2016
Table	6.2c
(In thousands)		Debt Securities			Equity Securities			Total Investments			Real Estate Acquired
Balance at December 31, 2015		$	1,228		$	2,855		$	4,083		$	12,149
Total realized/unrealized gains (losses):
Included in earnings and reported as net realized investment gains		—			3,579			3,579			—
Included in earnings and reported as losses incurred, net		—			—			—			(1,142		)
Purchases		—			4,258			4,258			36,859
Sales		(537		)	(6,424		)	(6,961		)	(36,118		)
Balance at December 31, 2016		$	691		$	4,268		$	4,959		$	11,748

Additional fair value disclosures related to our investment portfolio are included in Note 5 – “Investments.”

FINANCIAL LIABILITIES NOT CARRIED AT FAIR VALUE

Financial liabilities are incurred in the normal course of our business. Table 6.3 compares the carrying value and fair value of our financial liabilities disclosed, but not carried, at fair value as of December 31, 2018 and 2017. The fair values of our 5.75% Notes and 9% Debentures were based on observable market prices. The fair value of the FHLB Advance was estimated using cash flows discounted at current incremental borrowing rates for similar borrowing arrangements, and in all cases they are categorized as Level 2. See Note 7 - "Debt" for a description of the financial liabilities in table 6.3.



Financial liabilities not carried at fair value
Table	6.3
		December 31, 2018				December 31, 2017
(In thousands)		Carrying Value		Fair Value		Carrying Value		Fair Value
Liabilities
FHLB Advance		$	155,000	$	150,551	$	155,000	$	152,124
5.75% Notes		419,713		425,791		418,560		465,473
9% Debentures		256,872		338,069		256,872		353,507
Total financial liabilities		$	831,585	$	914,411	$	830,432	$	971,104

The 5.75% Notes and 9% Debentures are obligations of our holding company, MGIC Investment Corporation, and not of its subsidiaries.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Debt

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Debt



NOTE 7		Debt

DEBT OBLIGATIONS

Table 7.1 shows the carrying value of our long-term debt obligations as of December 31, 2018 and 2017.



Long-term debt obligations
Table	7.1
		December 31,
(In millions)		2018		2017
FHLB Advance - 1.91%, due February 2023		$	155.0	$	155.0
5.75% Notes, due August 2023 (par value: $425 million)		419.7		418.5
9% Debentures, due April 2063		256.9		256.9
Long-term debt, carrying value		$	831.6	$	830.4

FHLB Advance

MGIC borrowed $155.0 million in the form of a fixed rate advance from the Federal Home Loan Bank of Chicago ("Advance"). Interest on the Advance is payable monthly at an annual rate, fixed for the term of the Advance, of 1.91%. The principal of the Advance matures on February 10, 2023. MGIC may prepay the Advance at any time. Such prepayment would be below par if interest rates have risen after the Advance was originated, or above par if interest rates have declined. The Advance is secured by eligible collateral whose market value must be maintained at 102% of the principal balance of the Advance. MGIC provided eligible collateral from its investment portfolio.

5.75% Notes

Interest on the 5.75% Notes is payable semi-annually on February 15 and August 15 of each year, commencing on February 15, 2017. We have the option to redeem these notes, in whole or in part, at any time or from time to time prior to maturity at a redemption price equal to the greater of (i)100% of the aggregate principal amount of the notes to be redeemed and (ii) the make-whole amount, which is the sum of the present values of the remaining scheduled payments of principal and interest discounted at the treasury rate defined in the notes plus 50 basis points, plus, in each case, accrued interest thereon to, but excluding, the redemption date.

The 5.75% Notes have covenants customary for securities of this nature, including customary events of default, and further provide that the trustee or holders of at least 25% in aggregate principal amount of the outstanding 5.75% Notes may declare them immediately due and payable upon the occurrence of certain events of default after the expiration of the applicable grace period. In addition, in the case of an event of default arising from certain events of bankruptcy, insolvency or reorganization relating to the Company or any of its significant subsidiaries, the 5.75% Notes will become due and payable immediately. This description is not intended to be complete in all respects and is qualified in its entirety by the terms of the 5.75% Notes, including their covenants and events of default. We were in compliance with all covenants as of December 31, 2018.

9% Debentures

The 9% Debentures are currently convertible, at the holder's option, at an initial conversion rate, which is subject to adjustment, of 74.0741 common shares per $1,000 principal amount of the 9% Debentures at any time prior to the maturity date. This represents an initial conversion price of approximately $13.50 per share. If a holder elects to convert their 9% Debentures, deferred interest, if any, owed on the 9% Debentures being converted is also converted into shares of our common stock. The conversion rate for any deferred interest is based on the average price that our shares traded at during a 5-day period immediately prior to the election to convert. We have 19.0 million authorized shares reserved for conversion under our 9% debentures.

The 9% Debentures include a conversion feature that allows us, at our option, to make a cash payment to converting holders in lieu of issuing shares of common stock upon conversion of the 9% Debentures. We may redeem the 9% Debentures in whole or in part from time to time, at our option, at a redemption price equal to 100% of the principal amount of the 9% Debentures being redeemed, plus any accrued and unpaid interest, if the closing sale price of our common stock exceeds $17.55 for at least 20 of the 30 trading days preceding notice of the redemption.

Interest on the 9% Debentures is payable semi-annually in arrears on April 1 and October 1 of each year. As long as no event of default with respect to the debentures has occurred and is continuing, we may defer interest, under an optional deferral provision, for one or more consecutive interest periods up to 10 years without giving rise to an event of default. Deferred interest will accrue additional interest at the rate then applicable to the debentures. During an optional deferral period we may not pay or declare dividends on our common stock.

When interest on the 9% Debentures is deferred, we are required, not later than a specified time, to use reasonable commercial efforts to begin selling qualifying securities to persons who are not our affiliates. The specified time is one business day after we pay interest on the 9% Debentures that was not deferred, or if earlier, the fifth anniversary of the scheduled interest payment date on which the deferral started. Qualifying securities are common stock, certain warrants and certain non-cumulative perpetual preferred stock. The requirement to use such efforts to sell such securities is called the Alternative Payment Mechanism.

The net proceeds of Alternative Payment Mechanism sales are to be applied to the payment of deferred interest, including the compound portion. We cannot pay deferred interest other than from the net proceeds of Alternative Payment Mechanism sales, except at the final maturity of the debentures or at the tenth anniversary of the start of the interest deferral. The Alternative Payment Mechanism does not require us to sell common stock or warrants before the fifth anniversary of the interest payment date on which that deferral started if the net proceeds (counting any net proceeds of those securities previously sold under the Alternative Payment Mechanism) would exceed the 2% cap. The 2% cap is 2% of the average closing price of our common stock times the number of our outstanding shares of common stock. The average price is determined over a specified period ending before the issuance of the common stock or warrants being sold, and the number of outstanding shares is determined as of the date of our most recent publicly released financial statements.

We are not required to issue under the Alternative Payment Mechanism a total of more than 10 million shares of common stock, including shares underlying qualifying warrants. In addition, we may not issue under the Alternative Payment Mechanism qualifying preferred stock if the total net proceeds of all issuances would exceed 25% of the aggregate principal amount of the debentures.

The Alternative Payment Mechanism does not apply during any period between scheduled interest payment dates if there is a “market disruption event” that occurs over a specified portion of such period. Market disruption events include any material adverse change in domestic or international economic or financial conditions.

The provisions of the 9% Debentures are complex. The description above is not intended to be complete in all respects. Moreover, that description is qualified in its entirety by the terms of the 9% Debentures, including their covenants and events of default. We were in compliance with all covenants at December 31, 2018. The 9% Debentures rank junior to all of our existing and future senior indebtedness.

CREDIT FACILITY

As of December 31, 2018 and 2017, there were no amounts drawn on our unsecured revolving credit facility. The Credit Agreement with various lenders provides for a $175 million unsecured revolving credit facility maturing on March 21, 2020. We are required under the Credit Agreement to pay commitment fees on the average daily amount of the unused revolving commitments of the lenders, and an annual administrative fee to the administrative agent. Commitment fees are recognized as interest expense.

INTEREST PAYMENTS

Interest payments were $51.3 million during 2018, $57.8 million during 2017, and $49.5 million during 2016.

Loss Reserves

12 Months Ended

Dec. 31, 2018

Insurance Loss Reserves [Abstract]

Loss Reserves



NOTE 8		Loss Reserves

As described in Note 3 – “Summary of Significant Accounting Policies – Loss Reserves,” we establish reserves to recognize the estimated liability for losses and loss adjustment expenses ("LAE") related to defaults on insured mortgage loans. Loss reserves are established by estimating the number of loans in our inventory of delinquent loans that will result in a claim payment, which is referred to as the claim rate, and further estimating the amount of the claim payment, which is referred to as claim severity.

Estimation of losses is inherently judgmental. The conditions that affect the claim rate and claim severity include the current and future state of the domestic economy, including unemployment and the current and future strength of local housing markets; exposure on insured loans; the amount of time between default and claim filing; and curtailments and rescissions. The actual amount of the claim payments may be substantially different than our loss reserve estimates. Our estimates could be adversely affected by several factors, including a deterioration of regional or national economic conditions, including unemployment, leading to a reduction in borrowers’ income and thus their ability to make mortgage payments, and a drop in housing values which may affect borrower willingness to continue to make mortgage payments when the value of the home is below the mortgage balance. Changes to our estimates could result in a material impact to our consolidated results of operations and financial position, even in a stable economic environment.

LOSSES INCURRED

The “Losses incurred” section of table 8.1 below shows losses incurred on delinquencies that occurred in the current year and in prior years. The amount of losses incurred relating to delinquencies that occurred in the current year represents the estimated amount to be ultimately paid on such delinquencies. The amount of losses incurred relating to delinquencies that occurred in prior years represents the difference between the actual claim rate and severity associated with those delinquencies resolved in the current year compared to the estimated claim rate and severity at the prior year-end, as well as a re-estimation of amounts to be ultimately paid on delinquencies continuing from the end of the prior year. This re-estimation of the claim rate and severity is the result of our review of current trends in the delinquent inventory, such as percentages of delinquencies that have resulted in a claim, the amount of the claims relative to the average loan exposure, changes in the relative level of delinquencies by geography and changes in average loan exposure.

Losses incurred on delinquencies that occurred in the current year decreased in 2018 compared to 2017 and in 2017 compared to 2016, in each case, primarily due to a decrease in the number of new delinquencies, net of cures, as well as a decrease in the estimated claim rate on recently reported delinquencies.

LOSSES PAID

The “Losses paid” section of table 8.1 below shows the amount of losses paid on delinquencies that occurred in the current year and losses paid on delinquencies that occurred in prior years. For several years, the average time it took to receive a claim associated with a delinquency had increased significantly from our historical experience of approximately twelve months. This was, in part, due to new loss mitigation protocols established by servicers and to changes in some state foreclosure laws that may include, for example, a requirement for additional review and/or mediation processes. In recent quarters, we have experienced a decline in the average time it takes servicers to process foreclosures, which has reduced the average time to receive a claim associated with new delinquent notices that do not cure. All else being equal, the longer the period between delinquency and claim filing, the greater the severity.

Premium refunds

Our estimate of premiums to be refunded on expected claim payments is accrued for separately in "Other liabilities" on our consolidated balance sheets and approximated $40 million and $61 million at December 31, 2018 and 2017, respectively.

Table 8.1 provides a reconciliation of beginning and ending loss reserves for each of the past three years:



Development of reserves for losses and loss adjustment expenses
Table	8.1
(In thousands)		2018			2017			2016
Reserve at beginning of year		$	985,635		$	1,438,813		$	1,893,402
Less reinsurance recoverable		48,474			50,493			44,487
Net reserve at beginning of year		937,161			1,388,320			1,848,915

Losses incurred:
Losses and LAE incurred in respect of delinquent notices received in:
Current year		203,928			284,913			387,815
Prior years ⁽¹⁾		(167,366		)	(231,204		)	(147,658		)
Total losses incurred		36,562			53,709			240,157

Losses paid:
Losses and LAE paid in respect of delinquent notices received in:
Current year		7,298			11,267			14,823
Prior years		327,743			493,300			689,258
Reinsurance terminations		(2,009		)	301			(3,329		)
Total losses paid		333,032			504,868			700,752
Net reserve at end of year		640,691			937,161			1,388,320
Plus reinsurance recoverables		33,328			48,474			50,493
Reserve at end of year		$	674,019		$	985,635		$	1,438,813


⁽¹⁾	A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves. See table 8.2 below for more information about prior year loss development.

Table 8.2 below shows the development of reserves in 2018, 2017 and 2016 for previously received delinquencies.



Reserve development on previously received delinquencies
Table	8.2
(In millions)		2018			2017			2016
Decrease in estimated claim rate on primary delinquencies		$	(213	)	$	(248	)	$	(148	)
Increase in estimated severity on primary delinquencies		29			9			9
Change in estimates related to pool reserves, LAE reserves, reinsurance and other		17			8			(9		)
Total prior year loss development ⁽¹⁾		$	(167	)	$	(231	)	$	(148	)


⁽¹⁾	A negative number for prior year loss development indicates a redundancy of prior year loss reserves.

For the years ended December 31, 2018, 2017 and 2016, we experienced favorable development on previously received delinquencies. This development was, in part, due to the resolution of approximately 73%, 67% and 63% for the years ended December 31, 2018, 2017 and 2016, respectively, of the prior year delinquent inventory, with improved cure rates. During 2018 and 2017, cure activity on loans that were delinquent twelve months or more was significantly higher than our previous estimates. The favorable development for the years ended 2018, 2017, and 2016 was offset, in part, by an increase in the estimated severity on previously reported delinquencies remaining in the delinquent inventory.

DELINQUENT INVENTORY

A roll-forward of our primary delinquent inventory for the years ended December 31, 2018, 2017, and 2016 appears in table 8.3 below. The information concerning new notices and cures is compiled from monthly reports received from loan servicers. The level of new notice and cure activity reported in a particular month can be influenced by, among other things, the date on which a servicer generates its report, the number of business days in a month and transfers of servicing between loan servicers.



Primary delinquent inventory roll-forward
Table	8.3
		2018		2017		2016
Beginning delinquent inventory		46,556		50,282		62,633
New Notices		54,448		68,268		67,434
Cures		(60,511	)	(61,094	)	(65,516	)
Paid claims		(5,750	)	(9,206	)	(12,367	)
Rescissions and denials		(267	)	(357	)	(629	)
Other items removed from inventory		(1,578	)	(1,337	)	(1,273	)
Ending delinquent inventory		32,898		46,556		50,282

Hurricane activity

New delinquent notice activity increased in 2017 compared to 2016 (particularly in the fourth quarter) because of hurricane activity that primarily impacted Puerto Rico, Texas, and Florida in the third quarter of 2017. In response to the hurricanes, the Federal Emergency Management Agency declared Individual Assistance Disaster Areas ("IADA") which we used to identify new notices of delinquency for reserving and loss mitigation purposes. We received 9,294 new notices of delinquency on loans in the IADAs in the fourth quarter of 2017, which compares to 1,968 new notices in the same areas in the fourth quarter of 2016. Loans in our ending delinquent inventory within the IADAs were 12,446 and 7,162 as of December 31, 2017 and 2016, respectively. The majority of notices of delinquency received from the IADAs due to the hurricane activity cured during 2018.

Other items removed from inventory

During 2018, 2017, and 2016 our losses paid included amounts paid upon commutation of coverage on pools of non-performing loans ("NPLs"), and in 2016 our losses paid also included amounts paid in connection with settlements for disputes concerning our claims paying practices. The impacts of the commutations of coverage on NPLs and/or settlements in each of the past three years were as follows:


•	2018 - 1,578 notices removed from delinquent inventory with an amount paid of $50 million,


•	2017 - 1,337 notices removed from delinquent inventory with an amount paid of $54 million,


•	2016 - 1,273 notices removed from delinquent inventory with an amount paid of $53 million. In addition, we made a final payment of $42 million in connection with a 2012 settlement agreement with Freddie Mac regarding the aggregate loss limit under certain pool insurance policies.

Aging of delinquent inventory

Historically as a delinquency ages it becomes more likely to result in a claim. The new notice activity from hurricane impacted areas in the fourth quarter of 2017 increased the percentage of our delinquent inventory that has been delinquent for three months or less (table 8.4) as of December 31, 2017 when compared to December 31, 2016.

The number of consecutive months that a borrower has been delinquent is shown in the table below.



Primary delinquent inventory - consecutive months delinquent
Table	8.4
		December 31,
		2018		2017		2016
3 months or less		9,829		17,119		12,194
4 - 11 months		9,655		12,050		13,450
12 months or more⁽¹⁾		13,414		17,387		24,638
Total		32,898		46,556		50,282

3 months or less		30	%	37	%	24	%
4 - 11 months		29	%	26	%	27	%
12 months or more		41	%	37	%	49	%
Total		100	%	100	%	100	%

Primary claims received inventory included in ending delinquent inventory		809		954		1,385


⁽¹⁾	Approximately 38%, 45%, and 47% of the primary delinquent inventory delinquent for 12 consecutive months or more has been delinquent for at least 36 consecutive months as of December 31, 2018, 2017 and 2016, respectively.

POOL INSURANCE DEFAULT INVENTORY

Pool insurance default inventory decreased to 859 at December 31, 2018 from 1,309 at December 31, 2017 and 1,883 at December 31, 2016.

CLAIMS PAYING PRACTICES

Our loss reserving methodology incorporates our estimates of future rescissions. A variance between ultimate actual rescission rates and our estimates, as a result of the outcome of litigation, settlements or other factors, could materially affect our losses. Our estimate of premiums to be refunded on expected future rescissions is accrued for separately and is included in "Other liabilities" on our consolidated balance sheets.

For information about discussions and legal proceedings with customers with respect to our claims paying practices, including settlements that we believe are probable, as defined in ASC 450-20, see Note 17 – “Litigation and Contingencies.”

Reinsurance

12 Months Ended

Dec. 31, 2018

Reinsurance Disclosures [Abstract]

Reinsurance



NOTE 9		Reinsurance

Our consolidated financial statements reflect the effects of assumed and ceded reinsurance transactions. Assumed reinsurance refers to the acceptance of certain insurance risks that other insurance companies have underwritten. Ceded reinsurance involves transferring certain insurance risks (along with the related earned premiums) we have underwritten to other insurance companies who agree to share these risks. The purpose of ceded reinsurance is to protect us, at a cost, against losses arising from our mortgage guaranty policies covered by the agreement and to manage our capital requirements under PMIERs. Reinsurance is currently placed on a quota-share and excess of loss basis, but we also have immaterial captive reinsurance agreements that remain in effect.

Table 9.1 below shows the effect of all reinsurance agreements on premiums earned and losses incurred as reflected in the consolidated statements of operations.



Reinsurance
Table	9.1
		Years ended December 31,
(In thousands)		2018			2017			2016
Premiums earned:
Direct		$	1,084,748		$	1,059,973		$	1,058,545
Assumed		1,805			509			662
Ceded		(111,391		)	(125,735		)	(133,981		)
Net premiums earned		$	975,162		$	934,747		$	925,226

Losses incurred:
Direct		$	43,060		$	74,727		$	273,207
Assumed		331			183			1,138
Ceded		(6,829		)	(21,201		)	(34,188		)
Net losses incurred		$	36,562		$	53,709		$	240,157

QUOTA SHARE REINSURANCE

Each of the reinsurers under our quota share reinsurance agreements described below has an insurer financial strength rating of A- or better by Standard and Poor's Rating Services, A.M. Best, or both.

2018 QSR Transaction. Our 2018 quota share reinsurance agreement ("2018 QSR Transaction") provides coverage on eligible new business written in 2018. Under the 2018 QSR Transaction, we cede losses incurred and premiums on or after the effective date through December 31, 2029, at which time the agreement expires. Early termination of the agreement can be elected by us effective December 31, 2021, and annually thereafter, for a fee, or under specified scenarios for no fee upon prior written notice, including if we will receive less than 90% of the full credit amount under the PMIERs for the risk ceded in any required calculation period.

The structure of the 2018 QSR Transaction is a 30% quota share for all policies covered, with a 20% ceding commission as well as a profit commission. Generally, under the 2018 QSR Transaction, we will receive a profit commission provided that the loss ratio on the loans covered under the agreement remains below 62%.

2017 QSR Transaction. Our 2017 quota share reinsurance agreement ("2017 QSR Transaction") provides coverage on eligible new business written in 2017. Under our 2017 QSR Transaction we cede losses incurred and premiums on or after the effective date through December 31, 2028, at which time the agreement expires. Early termination of the agreement can be elected by us effective December 31, 2021 for a fee, or under specified scenarios for no fee upon prior written notice, including if we will receive less than 90% of the full credit amount under the PMIERs for the risk ceded in any required calculation period.

2015 QSR Transaction. Our 2015 quota share reinsurance agreement ("2015 QSR Transaction") provides coverage on eligible business written before 2017. Under the 2015 QSR Transaction we cede losses incurred and premiums through December 31, 2024, at which time the agreement expires. Early termination of the agreement can be elected by us for a fee on a bi-annual basis, or under specified scenarios for no fee upon prior written notice, including if we will receive less than 90% of the full credit amount under the PMIERs for the risk ceded in any required calculation period. Our next early termination option is at June 30, 2019 and requires 90 days' prior written notice.

The structure of both the 2017 QSR Transaction and 2015 QSR Transactions is a 30% quota share for all policies covered, with a 20% ceding commission as well as a profit commission. Generally, under the 2017 and 2015 QSR Transactions, we will receive a profit commission provided that the loss ratio on the loans covered under the agreement remains below 60%.

Table 9.2 provides a summary of our quota share reinsurance agreements, excluding captive agreements, for 2018, 2017 and 2016.



Quota share reinsurance
Table	9.2
		Years ended December 31,
(In thousands)		2018		2017		2016
Ceded premiums written and earned, net of profit commission ⁽¹⁾		$	108,337	$	120,974	$	125,460
Ceded losses incurred		6,543		22,336		30,201
Ceding commissions ⁽²⁾		51,201		49,321		47,629
Profit commission		147,667		125,629		112,685


⁽¹⁾	Under our QSR Transactions, premiums are ceded on an earned and received basis as defined in our agreements.


⁽²⁾	Ceding commissions are reported within Other underwriting and operating expenses, net on the consolidated statements of operations.

Under the terms of our QSR Transactions currently in effect, reinsurance premiums, ceding commission and profit commission are settled net on a quarterly basis. The reinsurance premium due after deducting the related ceding commission and profit commission is reported within "Other liabilities" on the consolidated balance sheets.

The reinsurance recoverable on loss reserves was $33.2 million as of December 31, 2018 and $39.3 million as of December 31, 2017. The reinsurance recoverable balance is secured by funds on deposit from the reinsurers which are based on the funding requirements of PMIERs that address ceded risk.

2019 QSR Transaction. We have agreed to terms on a QSR Transaction with a group of unaffiliated reinsurers with an effective date of January 1, 2019 ("2019 QSR Transaction"), which provides coverage on eligible new business written in 2019. Under the 2019 QSR Transaction, we cede losses incurred and premiums on or after the effective date through December 31, 2030, at which time the agreement expires. Early termination of the agreement can be elected by us effective December 31, 2021, and bi-annually thereafter, for a fee, or under specified scenarios for no fee upon prior written notice, including if we will receive less than 90% of the full credit amount under the PMIERs for the risk ceded in any required calculation period.

The structure of the 2019 QSR Transaction is a 30% quota share, with a one-time option, elected by us, to reduce the cede rate to either 25% or 20% effective July 1, 2020, or bi-annually thereafter, for a fee, for all policies covered, with a 20% ceding commission as well as a profit commission. Generally, under the 2019 QSR Transaction, we will receive a profit commission provided that the loss ratio on the loans covered under the agreement remains below 62%.

EXCESS OF LOSS REINSURANCE

On October 30, 2018, MGIC entered into a fully collateralized reinsurance agreement with Home Re 2018-1 Ltd. (“Home Re”), an unaffiliated special purpose insurer domiciled in Bermuda, that provides for up to $318.6 million of aggregate excess-of-loss reinsurance coverage as of August 1, 2018 on a portfolio of mortgage insurance policies having an insurance coverage in force date on or after July 1, 2016 and before January 1, 2018. For the reinsurance coverage period, MGIC will retain the first layer of $168.7 million of aggregate losses, and Home Re will then provide second layer coverage up to the outstanding reinsurance coverage amount. The premiums ceded to the reinsurer, Home Re, are composed of coverage premiums, initial expense and supplemental premiums. The coverage premiums are generally calculated as the difference between the amount of interest payable by Home Re on the notes it issued to raise funds to collateralize its reinsurance obligations to us, and the investment income collected on the collateral assets.

The aggregate excess of loss reinsurance coverage decreases over a ten-year period, subject to certain conditions, as the underlying covered mortgages amortize, principal is prepaid, or mortgage insurance losses are paid. MGIC has rights to terminate the reinsurance agreement, which includes an option to terminate on or after October 25, 2025. Home Re financed the coverage by issuing mortgage insurance-linked notes in an aggregate amount of $318.6 million to unaffiliated investors. The notes have ten-year legal maturities and are non-recourse to any assets of MGIC or its affiliates. The proceeds of the notes were deposited into a reinsurance trust for the benefit of MGIC that will be the source of reinsurance claim payments to MGIC and principal repayments on the mortgage insurance-linked notes.

The amount of monthly reinsurance coverage premium ceded will fluctuate due to change in one-month LIBOR and changes in money market rates that affect investment income collected on the assets in the reinsurance trust. As the reinsurance premium will vary based on changes in these rates, we concluded that the reinsurance agreement contains an embedded derivative that will be accounted for separately as a freestanding derivative. The fair value of the derivative at December 31, 2018, and the change in fair value from inception of the reinsurance agreement to December 31, 2018, was not material to our consolidated balance sheet and consolidated statement of operations, respectively. Total ceded premiums were $2.8 million for the year ended December 31, 2018.

In connection with entering into the reinsurance agreement with Home Re, we concluded that the risk transfer requirements for reinsurance accounting were met as Home Re is assuming significant insurance risk and a reasonable possibility of significant loss. In addition, we assessed whether Home Re was a variable interest entity (“VIE”). A VIE is a legal entity that does not have sufficient equity at risk to finance its activities without additional subordinated financial support or is structured such that equity investors lack the ability to make sufficient decisions relating to the entity’s operations through voting rights or do not substantively participate in gains and losses of the entity. We concluded that Home Re is a VIE. However, given that MGIC (1) does not have the unilateral power to direct the activities that most significantly affect Home Re’s economic performance and (2) does not have the obligation to absorb losses or the right to receive benefits of Home Re, consolidation of Home Re is not required.

We are required to disclose our maximum exposure to loss, which we consider to be an amount that we could be required to record in our statement of operations, as a result of our involvement with this VIE. As of December 31, 2018, we did not have exposure to the VIE as we have no investment in the VIE and had no reinsurance claim payments due from the VIE under our reinsurance agreement. We are unable to determine the timing or extent of losses that may be ceded under the reinsurance agreement. The VIE assets are deposited in a reinsurance trust for the benefit of MGIC that will be the source of reinsurance claim payments to MGIC. The purpose of the reinsurance trust is to provide security to MGIC for the obligations of the VIE under the reinsurance agreement. The trustee of the reinsurance trust, a recognized provider of corporate trust services, has established a segregated account within the reinsurance trust for the benefit of MGIC, pursuant to the trust agreement. The trust agreement is governed by, and construed in accordance with, the laws of the State of New York. If the trustee of the reinsurance trust failed to distribute claim payments to us as provided in the reinsurance trust, we would incur a loss related to our losses ceded under the reinsurance agreement and deemed unrecoverable. We are also unable to determine the impact such possible failure by the trustee to perform pursuant to the reinsurance trust agreement may have on our consolidated financial statements. As a result, we are unable to quantify our maximum exposure to loss related to our involvement with the VIE. MGIC has certain termination rights under the reinsurance agreement should its claims not be paid. We consider our exposure to loss from our reinsurance agreement with the VIE to be remote.

The following presents the total assets of Home Re as of December 31, 2018.



Home Re total assets
Table	9.3

(In thousands)		Total VIE Assets
Home Re 2018-1 Ltd.		$	318,636

The reinsurance trust agreement provides that the trust assets may generally only be invested in certain money market funds that (i) invest at least 99.5% of their total assets in cash or direct U.S. federal government obligations, such as U.S. Treasury bills, as well as other short-term securities backed by the full faith and credit of the U.S. federal government or issued by an agency of the U.S. federal government, (ii) have a principal stability fund rating of “AAAm” by S&P or a money market fund rating of “Aaa-mf” by Moody’s as of the Closing Date and thereafter maintain any rating with either S&P or Moody’s, and (iii) are permitted investments under the applicable credit for reinsurance laws and applicable PMIERs credit for reinsurance requirements.

The assets of Home Re provide capital credit under the PMIERs financial requirements (see Note 1 - "Nature of Business"). A decline in the assets available to pay claims would reduce the capital credit available to MGIC.

Other Comprehensive Income (Loss)

12 Months Ended

Dec. 31, 2018

Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]

Other Comprehensive Income (Loss)



NOTE 10		Other Comprehensive Income (Loss)

The pretax components of our other comprehensive income (loss) and related income tax (expense) benefit for the years ended December 31, 2018, 2017 and 2016 are included in table 10.1 below.



Components of other comprehensive income (loss)
Table	10.1
(In thousands)		2018			2017			2016
Net unrealized investment (losses) gains arising during the year		$	(81,834	)	$	69,052		$	(5,425	)
Income tax benefit (expense)		17,188			(21,505		)	1,776
Net of taxes		(64,646		)	47,547			(3,649		)

Net changes in benefit plan assets and obligations		(19,958		)	(8,983		)	(14,799		)
Income tax benefit		4,191			3,144			5,179
Net of taxes		(15,767		)	(5,839		)	(9,620		)

Net changes in unrealized foreign currency translation adjustment		—			45			(1,463		)
Income tax (expense) benefit		—			(14		)	512
Net of taxes		—			31			(951		)

Total other comprehensive (loss) income		(101,792		)	60,114			(21,687		)
Total income tax benefit (expense), net		21,379			(18,375		)	7,467
Total other comprehensive (loss) income, net of tax		$	(80,413	)	$	41,739		$	(14,220	)

The pretax and related income tax benefit (expense) components of the amounts reclassified from our accumulated other comprehensive loss ("AOCL") to our consolidated statements of operations for the years ended December 31, 2018, 2017 and 2016 are included in table 10.2 below.



Reclassifications from AOCL
Table	10.2
(In thousands)		2018			2017			2016
Reclassification adjustment for net realized (losses) gains included in net income ⁽¹⁾		$	(7,037	)	$	(2,580	)	$	6,207
Income tax benefit (expense)		1,477			903			(2,050		)
Net of taxes		(5,560		)	(1,677		)	4,157

Reclassification adjustment related to benefit plan assets and obligations ⁽²⁾		(2,232		)	906			1,480
Income tax benefit (expense)		469			(317		)	(518		)
Net of taxes		(1,763		)	589			962

Reclassification adjustment related to foreign currency ⁽³⁾		—			—			1,467
Income tax (expense)		—			—			(513		)
Net of taxes		—			—			954

Total reclassifications		(9,269		)	(1,674		)	9,154
Total income tax benefit (expense), net		1,946			586			(3,081		)
Total reclassifications, net of tax		$	(7,323	)	$	(1,088	)	$	6,073


⁽¹⁾	(Decreases) increases Net realized investment gains on the consolidated statements of operations.


⁽²⁾	Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations.


⁽³⁾	Increases (decreases) Other revenue on the consolidated statements of operations.

A roll-forward of AOCL for the years ended December 31, 2018, 2017, and 2016, including amounts reclassified from AOCL, is included in table 10.3 below.



Roll-forward of AOCL
Table	10.3
(In thousands)		Net unrealized gains and losses on available-for-sale securities			Net benefit plan assets and obligations recognized in shareholders' equity			Net unrealized foreign currency translation			Total AOCL
Balance, December 31, 2015, net of tax		$	(17,148	)	$	(44,652	)	$	920		$	(60,880	)
Other comprehensive income (loss) before reclassifications		508			(8,658		)	3			(8,147		)
Less: Amounts reclassified from AOCL		4,157			962			954			6,073
Balance, December 31, 2016, net of tax		(20,797		)	(54,272		)	(31		)	(75,100		)
Other comprehensive income (loss) before reclassifications		45,870			(5,250		)	31			40,651
Less: Amounts reclassified from AOCL		(1,677		)	589			—			(1,088		)
Less: Amounts reclassified for lower enacted corporate tax rate		(2,525		)	12,947			—			10,422
Balance, December 31, 2017, net of tax		29,275			(73,058		)	—			(43,783		)
Cumulative effect of adopting the accounting standard update for financial instruments		(18		)	—			—			(18		)
Other comprehensive income (loss) before reclassifications		(70,206		)	(17,530		)	—			(87,736		)
Less: Amounts reclassified from AOCL		(5,560		)	(1,763		)	—			(7,323		)
Balance, December 31, 2018, net of tax		$	(35,389	)	$	(88,825	)	$	—		(124,214		)

Benefit Plans

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Benefit Plans



NOTE 11		Benefit Plans

We have a non-contributory defined benefit pension plan covering substantially all domestic employees, as well as a supplemental executive retirement plan. We also offer both medical and dental benefits for retired domestic employees, their eligible spouses and dependents under a postretirement benefit plan. The following tables 11.1, 11.2, and 11.3 provide the components of aggregate annual net periodic benefit cost for each of the years ended December 31, 2018, 2017, and 2016 and changes in the benefit obligation and the funded status of the pension, supplemental executive retirement and other postretirement benefit plans as recognized in the consolidated balance sheets as of December 31, 2018 and 2017.



Components of net periodic benefit cost
Table	11.1
		Pension and Supplemental Executive Retirement Plans									Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2016			12/31/2018			12/31/2017			12/31/2016
1. Company Service Cost		$	10,530		$	9,556		$	9,130		$	1,160		$	813		$	751
2. Interest Cost		15,095			15,475			15,906			834			706			704
3. Expected Return on Assets		(22,250		)	(20,099		)	(19,508		)	(6,359		)	(5,248		)	(4,886		)
4. Other Adjustments		—			—			—			—			—			—
Subtotal		3,375			4,932			5,528			(4,365		)	(3,729		)	(3,431		)
5. Amortization of:
a. Net Transition Obligation/(Asset)		—			—			—			—			—			—
b. Net Prior Service Cost/(Credit)		(351		)	(426		)	(687		)	(4,104		)	(6,649		)	(6,649		)
c. Net Losses/(Gains)		6,937			6,169			5,856			(250		)	—			—
Total Amortization		6,586			5,743			5,169			(4,354		)	(6,649		)	(6,649		)
6. Net Periodic Benefit Cost		9,961			10,675			10,697			(8,719		)	(10,378		)	(10,080		)
7. Cost of settlements		—			—			1,277			—			—			—
8. Total Expense for Year		$	9,961		$	10,675		$	11,974		$	(8,719	)	$	(10,378	)	$	(10,080	)



Development of funded status
Table	11.2
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
Actuarial Value of Benefit Obligations
1. Measurement Date		12/31/2018			12/31/2017			12/31/2018			12/31/2017
2. Accumulated Benefit Obligation		$	375,562		$	411,996		$	28,085		$	24,716

Funded Status/Asset (Liability) on the Consolidated Balance Sheet
1. Projected Benefit Obligation		$	(376,153	)	$	(417,770	)	$	(28,085	)	$	(24,716	)
2. Plan Assets at Fair Value		359,719			401,142			77,762			85,303
3. Funded Status - Overfunded/Asset		N/A			N/A			$	49,677		$	60,587
4. Funded Status - Underfunded/Liability		(16,434		)	(16,628		)	N/A			N/A



Accumulated other comprehensive income (loss)
Table	11.3
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018		12/31/2017
1. Net Actuarial (Gain)/Loss		$	110,321		$	109,904		$	939	$	(10,234	)
2. Net Prior Service Cost/(Credit)		(1,513		)	(1,850		)	2,690		(5,342		)
3. Net Transition Obligation/(Asset)		—			—			—		—
4. Total at Year End		$	108,808		$	108,054		$	3,629	$	(15,576	)

The amortization of gains and losses resulting from actual experience different from assumed experience or changes in assumptions including discount rates is included as a component of Net Periodic Benefit Cost/(Income) for the year. The gain or loss in excess of a 10% corridor is amortized by the average remaining service period of participating employees expected to receive benefits under the plan.

Table 11.4 shows the changes in the projected benefit obligation for 2018 and 2017.



Change in projected benefit / accumulated benefit
Table	11.4
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
1. Benefit Obligation at Beginning of Year		$	417,770		$	369,808		$	24,716		$	17,378
2. Company Service Cost		10,530			9,556			1,160			813
3. Interest Cost		15,095			15,475			834			706
4. Plan Participants' Contributions		—			—			475			395
5. Net Actuarial (Gain)/Loss due to Assumption Changes		(36,132		)	38,496			(1,209		)	5,981
6. Net Actuarial (Gain)/Loss due to Plan Experience		2,487			2,338			(692		)	924
7. Benefit Payments from Fund ⁽¹⁾		(32,674		)	(17,578		)	(1,077		)	(1,404		)
8. Benefit Payments Directly by Company		(908		)	(335		)	—			—
9. Plan Amendments		(15		)	10			3,928			—
10. Other Adjustment		—			—			(50		)	(77		)
11. Benefit Obligation at End of Year		$	376,153		$	417,770		$	28,085		$	24,716


⁽¹⁾	Includes lump sum payments of $20.9 million and $6.3 million in 2018 and 2017, respectively, from our pension plan to eligible participants, which were former employees with vested benefits.

The decrease in our pension and supplemental executive retirement plans obligation in 2018 compared to 2017 was primarily due to an increase in the discount rate used to calculate the obligation and a higher amount of benefits paid from the fund. The increase in our other postretirement plan obligation was primarily due to a plan amendment, offset by an increase in the discount rate used to calculate the obligation. Table 11.8 below includes the actuarial assumptions used to calculate the benefit obligations of our plans for 2018 and 2017.

Tables 11.5 and 11.6 shows the changes in the fair value of the net assets available for plan benefits, and changes in other comprehensive income (loss) during 2018 and 2017.



Change in plan assets
Table	11.5
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
1. Fair Value of Plan Assets at Beginning of Year		$	401,142		$	360,900		$	85,303		$	70,408
2. Company Contributions		10,908			9,435			—			—
3. Plan Participants' Contributions		—			—			475			395
4. Benefit Payments from Fund		(32,674		)	(17,578		)	(1,077		)	(1,404		)
5. Benefit Payments paid directly by Company		(908		)	(335		)	—			—
6. Actual Return on Assets		(19,583		)	48,720			(6,464		)	16,299
7. Other Adjustment		834			—			(475		)	(395		)
8. Fair Value of Plan Assets at End of Year		$	359,719		$	401,142		$	77,762		$	85,303



Change in accumulated other comprehensive income (loss) ("AOCI")
Table	11.6
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
1. AOCI in Prior Year		$	108,054		$	101,575		$	(15,576	)	$	(18,079	)
2. Increase/(Decrease) in AOCI
a. Recognized during year - Prior Service (Cost)/Credit		351			426			4,104			6,649
b. Recognized during year - Net Actuarial (Losses)/Gains		(6,937		)	(6,169		)	250			—
c. Occurring during year - Prior Service Cost		(15		)	10			3,928			—
d. Occurring during year - Net Actuarial Losses/(Gains)		7,355			12,212			10,923			(4,146		)
3. AOCI in Current Year		$	108,808		$	108,054		$	3,629		$	(15,576	)

Table 11.7 shows the amount of amortization on components of net periodic benefit costs expected to be recognized during the year ending December 31, 2019.



Amortization expected to be recognized during fiscal year ending
Table	11.7
		Pension and Supplemental Executive Retirement Plans			Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2018
1. Amortization of Net Transition Obligation/(Asset)		$	—		$	—
2. Amortization of Prior Service Cost/(Credit)		(280		)	(34		)
3. Amortization of Net Losses/(Gains)		8,271			—

The projected benefit obligations, net periodic benefit costs and accumulated postretirement benefit obligation for the plans were determined using the following weighted average assumptions.



Actuarial assumptions
Table	11.8
		Pension and Supplemental Executive Retirement Plans				Other Postretirement Benefits
		12/31/2018		12/31/2017		12/31/2018		12/31/2017
Weighted-Average Assumptions Used to Determine
Benefit Obligations at year end
1. Discount Rate		4.40	%	3.75	%	4.25	%	3.55	%
2. Rate of Compensation Increase		3.00	%	3.00	%	N/A		N/A

Weighted-Average Assumptions Used to Determine
Net Periodic Benefit Cost for Year
1. Discount Rate		3.75	%	4.30	%	3.55	%	3.95	%
2. Expected Long-term Return on Plan Assets		5.75	%	5.75	%	7.50	%	7.50	%
3. Rate of Compensation Increase		3.00	%	3.00	%	N/A		N/A

Assumed Health Care Cost Trend Rates at year end
1. Health Care Cost Trend Rate Assumed for Next Year		N/A		N/A		6.25	%	6.50	%
2. Rate to Which the Cost Trend Rate is Assumed to Decline (Ultimate Trend Rate)		N/A		N/A		5.00	%	5.00	%
3. Year That the Rate Reaches the Ultimate Trend Rate		N/A		N/A		2024		2024

In selecting a discount rate, we performed a hypothetical cash flow bond matching exercise, matching our expected pension plan and postretirement medical plan cash flows, respectively, against a selected portfolio of high quality corporate bonds. The modeling was performed using a bond portfolio of noncallable bonds with at least $50 million outstanding. The average yield of these hypothetical bond portfolios was used as the benchmark for determining the discount rate. In selecting the expected long-term rate of return on assets, we considered the average rate of earnings expected on the classes of funds invested or to be invested to provide for the benefits of these plans. This included considering the trusts' targeted asset allocation for the year and the expected returns likely to be earned over the next 20 years.

The year-end asset allocations of the plans are shown in table 11.9 below.



Plan assets
Table	11.9
		Pension Plan				Other Postretirement Benefits
		12/31/2018		12/31/2017		12/31/2018		12/31/2017
1. Equity Securities		23	%	21	%	100	%	100	%
2. Debt Securities		77	%	79	%	—	%	—	%
3. Total		100	%	100	%	100	%	100	%

In accordance with fair value guidance, we applied the following fair value hierarchy in order to measure fair value of our benefit plan assets:



è	Level 1	Quoted prices for identical instruments in active markets that we can access. Financial assets using Level 1 inputs include equity securities, mutual funds, money market funds, certain U.S. Treasury securities and exchange traded funds ("ETFs").
è	Level 2	Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and inputs, other than quoted prices, that are observable in the marketplace for the instrument. The observable inputs are used in valuation models to calculate the fair value of the instruments. Financial assets using Level 2 inputs include certain municipal, corporate and foreign bonds, obligations of U.S. government corporations and agencies, and pooled equity accounts.

To determine the fair value of securities in Level 1 and Level 2 of the fair value hierarchy, independent pricing sources have been used. One price is provided per security based on observable market data. To ensure securities are appropriately classified in the fair value hierarchy, we review the pricing techniques and methodologies of the independent pricing sources and believe that their policies adequately consider market activity, either based on specific transactions for the issue valued or based on modeling of securities with similar credit quality, duration, yield and structure that were recently traded. A variety of inputs are used by the independent pricing sources including benchmark yields, reported trades, non-binding broker/dealer quotes, issuer spreads, two sided markets, benchmark securities, bids, offers and reference data including market research publications. Inputs may be weighted differently for any security, and not all inputs are used for each security evaluation. Market indicators, industry and economic events are also considered. This information is evaluated using a multidimensional pricing model. In addition, on a quarterly basis, we perform quality controls over values received from the pricing source (the “Trustee”) which include comparing values to other independent pricing sources. In addition, we review annually the Trustee’s auditor’s report on internal controls in order to determine that their controls around valuing securities are operating effectively. We have not made any adjustments to the prices obtained from the independent sources.

Tables 11.10a and 11.10b set forth by level, within the fair value hierarchy, the pension plan assets and related accrued investment income at fair value as of December 31, 2018 and 2017. There were no securities that used Level 3 inputs.



Pension plan assets at fair value as of December 31, 2018
Table	11.10a
(In thousands)		Level 1		Level 2		Total
Domestic Mutual Funds		$	13,744	$	—	$	13,744
Corporate Bonds		—		181,363		181,363
U.S. Government Securities		19,904		1,324		21,228
Municipal Bonds		—		43,424		43,424
Foreign Bonds		—		30,113		30,113
ETFs		5,241		—		5,241
Pooled Equity Accounts		—		64,606		64,606
Total Assets at fair value		$	38,889	$	320,830	$	359,719



Pension plan assets at fair value as of December 31, 2017
Table	11.10b
(In thousands)		Level 1		Level 2		Total
Domestic Mutual Funds		$	1,006	$	—	$	1,006
Corporate Bonds		—		202,840		202,840
U.S. Government Securities		17,996		1,400		19,396
Municipal Bonds		—		62,293		62,293
Foreign Bonds		—		32,949		32,949
ETFs		5,734		—		5,734
Pooled Equity Accounts		—		76,924		76,924
Total Assets at fair value		$	24,736	$	376,406	$	401,142

The pension plan has implemented a strategy to reduce risk through the use of a targeted funded ratio. The liability driven component is key to the asset allocation. The liability driven component seeks to align the duration of the fixed income asset allocation with the expected duration of the plan liabilities or benefit payments. Overall asset allocation is dynamic and specifies target allocation weights and ranges based on the funded status.

An improvement in funded status results in the de-risking of the portfolio, allocating more funds to fixed income and less to equity. A decline in funded status would result in a higher allocation to equity. The maximum equity allocation is 40%.

The equity investments use combinations of mutual funds, ETFs, and pooled equity account structures focused on the following strategies:



Strategy	Objective	Investment types
Return seeking growth	Funded ratio improvement over the long term	●	Global quality growth
Return seeking growth	Funded ratio improvement over the long term	●	Global low volatility
Return seeking bridge	Downside protection in the event of a declining equity market	●	Enduring asset
Return seeking bridge		●	Durable company

The fixed income objective is to preserve capital and to provide monthly cash flows for the payment of plan liabilities. Fixed income investments can include government, government agency, corporate, mortgage-backed, asset-backed, and municipal securities, and other classes of bonds. The duration of the fixed income portfolio has an objective of being within one year of the duration of the accumulated benefit obligation. The fixed income investments have an objective of a weighted average credit of A3/A-/A- by Moody’s, S&P, and Fitch, respectively.

Tables 11.11a and 11.11b set forth the other postretirement benefits plan assets at fair value as of December 31, 2018 and 2017. All are Level 1 assets.



Other postretirement benefits plan assets at fair value as of December 31, 2018
Table	11.11a
(In thousands)		Level 1		Total
Domestic Mutual Funds		$	60,405	$	60,405
International Mutual Funds		17,357		17,357
Total Assets at fair value		$	77,762	$	77,762



Other postretirement benefits plan assets at fair value as of December 31, 2017
Table	11.11b
(In thousands)		Level 1		Total
Domestic Mutual Funds		$	64,489	$	64,489
International Mutual Funds		20,814		20,814
Total Assets at fair value		$	85,303	$	85,303

Our postretirement plan portfolio is designed to achieve the following objectives over each market cycle and for at least 5 years:

è Total return should exceed growth in the Consumer Price Index by 5.75% annually

è Achieve competitive investment results

The primary focus in developing asset allocation ranges for the portfolio is the assessment of the portfolio's investment objectives and the level of risk that is acceptable to obtain those objectives. To achieve these objectives the minimum and maximum allocation ranges for fixed income securities and equity securities are:



	Minimum		Maximum
Equities (long only)	70	%	100	%
Real estate	0	%	15	%
Commodities	0	%	10	%
Fixed income/Cash	0	%	10	%

Given the long term nature of this portfolio and the lack of any immediate need for significant cash flow, it is anticipated that the equity investments will consist of growth stocks and will typically be at the higher end of the allocation ranges above.

Investment in international mutual funds is limited to a maximum of 30% of the equity range. The allocation as of December 31, 2018 included 3% that was primarily invested in equity securities of emerging market countries and another 19% was invested in securities of companies primarily based in Europe and the Pacific Basin.

Tables 11.12 and 11.13 show the current and estimated future contributions and benefit payments.



Company contributions
Table	11.12
		Pension and Supplemental Executive Retirement Plans		Other Postretirement Benefits
(In thousands)		12/31/2018		12/31/2018
Company Contributions for the Year Ending:
1. Current		$	10,908	$	—
2. Current + 1		10,650		—



Benefits payments - total
Table	11.13
		Pension and Supplemental Executive Retirement Plans		Other Postretirement Benefits
(In thousands)		12/31/2018		12/31/2018
Actual Benefit Payments for the Year Ending:
1. Current		$	33,582	$	652
Expected Benefit Payments for the Year Ending:
2. Current + 1		33,258		1,352
3. Current + 2		28,688		1,650
4. Current + 3		30,574		1,916
5. Current + 4		30,490		2,386
6. Current + 5		30,510		2,613
7. Current + 6 - 10		143,389		14,065

HEALTH CARE SENSITIVITIES

Assumed health care cost trend rates have a significant effect on the amounts reported for the other postretirement benefits plan. A 1 percentage point change in the health care trend rate assumption would have the following effects on other postretirement benefits:



Health care trend rate assumption
Table	11.14
(In thousands)		1-Percentage Point Increase		1-Percentage Point Decrease
Effect on total service and interest cost components		$	327	$	(282	)
Effect on postretirement benefit obligation		3,221		(2,866		)

PROFIT SHARING AND 401(K)

We have a profit sharing and 401(k) savings plan for employees. At the discretion of the Board of Directors, we may make a contribution to the plan of up to 5% of each participant's eligible compensation. We provide a matching 401(k) savings contribution for employees on their before-tax contributions at a rate of 80% of the first $1,000 contributed and 40% of the next $2,000 contributed. For employees hired after January 1, 2014, the match is 100% up to 4% contributed. We recognized expenses related to these plans of $6.0 million, $6.0 million and $5.9 million in 2018, 2017 and 2016, respectively.

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes



NOTE 12		Income Taxes

Net deferred tax assets and liabilities as of December 31, 2018 and 2017 are as follows:



Deferred tax assets and liabilities
Table	12.1
(In thousands)		2018			2017
Total deferred tax assets		$	83,082		$	258,663
Total deferred tax liabilities		(13,898		)	(24,282		)
Net deferred tax asset		$	69,184		$	234,381

Table 12.2 includes the components of the net deferred tax asset as of December 31, 2018 and 2017.



Deferred tax components
Table	12.2
(In thousands)		2018			2017
Unearned premium reserves		$	31,808		$	29,196
Benefit plans		(5,047		)	(7,162		)
Federal net operating loss		—			155,839
Loss reserves		3,113			4,994
Unrealized depreciation (appreciation) in investments		9,407			(7,782		)
Mortgage investments		8,307			8,963
Deferred compensation		8,662			7,265
AMT credit carryforward		17,521			37,017
Other, net		(4,587		)	6,051
Net deferred tax asset		$	69,184		$	234,381

We used the remaining balance of our Federal net operating loss carryforward to offset taxable income during 2018. We believe that all gross deferred tax assets at December 31, 2018 are fully realizable and no valuation allowance has been established.

Table 12.3 summarizes the components of the provision for (benefit from) income taxes:



Provision for (benefit from) income taxes
Table	12.3
(In thousands)		2018			2017		2016
Current Federal		$	(16,272	)	$	73,348	$	9,470
Deferred Federal		185,598			351,677		160,657
Other		4,727			3,710		2,070
Provision for income taxes		$	174,053		$	428,735	$	172,197

Our income tax expense for 2017 reflects the remeasurement of our net deferred tax assets to reflect the lower corporate tax rate of 21% under the Tax Act. As a result of the lower tax rate, we recorded a decrease to our net deferred tax assets of $133 million with a corresponding increase to our deferred income tax expense for the year ended December 31, 2017.

Current federal income tax payments were $12.2 million, $22.0 million, and $4.5 million in 2018, 2017 and 2016, respectively.

Table 12.6 reconciles the federal statutory income tax rate to our effective tax provision rate.



Effective tax rate reconciliation
Table	12.6
		2018		2017		2016
Federal statutory income tax rate		21.0	%	35.0	%	35.0	%
Additional income tax provision related to the rate decrease included in the Tax Act		—	%	17.0	%	—	%
Additional income tax provision related to IRS litigation		(0.3	)%	3.7	%	0.1	%
Tax exempt municipal bond interest		(0.7	)%	(1.4	)%	(1.9	)%
Other, net		0.6	%	0.4	%	0.3	%
Effective tax rate		20.6	%	54.7	%	33.5	%

As previously disclosed, the Internal Revenue Service ("IRS") completed examinations of our federal income tax returns for the years 2000 through 2007 and issued proposed assessments for taxes, interest and penalties related to our treatment of the flow-through income and loss from an investment in a portfolio of residual interests of Real Estate Mortgage Investment Conduits ("REMICs").

In 2014, we received Notices of Deficiency (commonly referred to as "90 day letters") from the IRS. We filed a petition with the U.S. Tax Court contesting most of the IRS' proposed adjustments reflected in the Notices of Deficiency. In July 2018, we finalized an agreement with the IRS to settle all issues in the examinations and related U.S. Tax Court case; the settlement was approved by the U.S. Tax Court on July 26, 2018. As a result of our settlement, we made federal tax and interest payments of $14.8 million during 2018. We also made state tax and interest payments of $36.8 million during 2018. The impact of the agreed upon settlement was previously reflected in our consolidated statements of operations.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is shown in table 12.7.



Unrecognized tax benefits reconciliation
Table	12.7
(In thousands)		2018			2017			2016
Balance at beginning of year		$	142,821		$	108,245		$	107,120
Additions for tax positions of prior years		—			35,003			1,125
Reductions for tax positions of prior years		(3,070		)	(427		)	—
Settlements		(139,751		)	—			—
Balance at end of year		$	—		$	142,821		$	108,245

With the approval of our settlement by the U.S. Tax Court, we have no unrecognized tax benefits at December 31, 2018. We recognize interest accrued and penalties related to unrecognized tax benefits in income taxes. During 2018, we recognized an interest benefit of $3.1 million. As of December 31, 2017, we had $52.0 million of accrued interest related to uncertain tax positions. The statute of limitations related to the consolidated federal income tax return is closed for all years prior to 2015.

Shareholders' Equity

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Note [Abstract]

Shareholders' Equity



NOTE 13		Shareholders' Equity

CHANGE IN ACCOUNTING PRINCIPLE

As of January 1, 2018, the updated guidance of "Recognition and Measurement of Financial Assets and Financial Liabilities" became effective. The application of this guidance resulted in an immaterial cumulative effect adjustment to our 2018 beginning accumulated other comprehensive (loss) income and retained earnings to recognize unrealized gains on equity securities.

As of January 1, 2017, we adopted the updated guidance of "Improvements to Employee Share-Based Compensation Accounting." The adoption of this guidance resulted in an immaterial cumulative effect adjustment to our 2017 beginning retained earnings. For the year ending December 31, 2017, we adopted the updated guidance of "Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income." The adoption of this guidance resulted in a $10.4 million reclassification from accumulated other comprehensive loss to retained earnings in the fourth quarter of 2017.

SHARE REPURCHASE PROGRAM

On April 26, 2018, our Board of Directors authorized a share repurchase program under which we may repurchase up to $200 million of our common stock through the end of 2019. Repurchases may be made from time to time on the open market or through privately negotiated transactions. The repurchase program may be suspended for periods or discontinued at any time.

During 2018, we repurchased approximately 16.0 million shares of our common stock at a weighted average cost per share of $10.95, which included commissions. As of December 31, 2018, the authorized share repurchase program had approximately $25 million remaining.

2017 CAPITAL TRANSACTIONS

2% Notes

In April 2017, holders of approximately $202.5 million of the outstanding principal amount of our 2% Notes exercised their rights to convert their notes into shares of our common stock resulting in the delivery of approximately 29.1 million shares of our common stock to the holders. The transactions included the delivery of approximately 18.7 million from our treasury stock and an additional 10.4 million of newly issued shares. Shareholders' equity was increased by the carrying value of the notes at the time of conversion.

2016 CAPITAL TRANSACTIONS

5% Notes

In 2016, we repurchased $188.5 million in aggregate principal of our 5% Notes at a purchase price of $195.5 million, plus accrued interest using funds held at our holding company. The excess of the purchase price over carrying value was reflected as a loss on debt extinguishment of $7.9 million on our consolidated statement of operations.

2% Notes

In 2016, we entered into privately negotiated agreements to repurchase $292.4 million in aggregate principal of our outstanding 2% Notes at a purchase price of $362.1 million, plus accrued interest. We funded the purchases with $230.7 million of cash, using proceeds from the issuance of our 5.75% Notes, and by issuing to certain sellers approximately 18.3 million shares of our common stock. The excess of the purchase price over carrying value is reflected as a loss of debt extinguishment of $74.3 million on our consolidated statement of operations for the year ended December 31, 2016. As of December 31, 2016, we had repurchased all of the shares issued as partial consideration for our 2% Notes repurchases. The weighted average cost per share was $8.03, which included commissions, and the aggregate purchase amount was $147.1 million.

9% Debentures

In 2016, MGIC purchased $132.7 million in aggregate principal of our outstanding 9% Debentures at a purchase price of $150.7 million, plus accrued interest. The 9% Debentures include a conversion feature that allows us, at our option, to make a cash payment to converting holders in lieu of issuing shares of common stock upon conversion of the 9% Debentures. The accounting standards applicable to extinguishment of debt with a cash conversion feature require the consideration paid to be allocated between the extinguishment of the liability component and reacquisition of the equity component. The purchase of the 9% Debentures resulted in an $8.3 million loss on debt extinguishment on the consolidated statement of operations for the year ended December 31, 2016, which represents the difference between the fair value and the carrying value of the liability component on the purchase date. In addition, our shareholders' equity was separately reduced by $6.3 million as of December 31, 2016. This reduction represents the allocated portion of the consideration paid to reacquire the equity component of the 9% Debentures, net of tax.

Statutory Information

12 Months Ended

Dec. 31, 2018

Statutory Capital [Abstract]

Statutory Information



NOTE 14		Statutory Information

STATUTORY ACCOUNTING PRINCIPLES

The statutory financial statements of our insurance companies are presented on the basis of accounting principles prescribed, or practices permitted, by the Office of the Commissioner of Insurance of the State of Wisconsin (the "OCI"), which has adopted the National Association of Insurance Commissioners ("NAIC") Statements of Statutory Accounting Principles ("SSAP") as the basis of its statutory accounting principles. In converting from statutory to GAAP, typical adjustments include deferral of policy acquisition costs, the inclusion of net unrealized holding gains or losses in shareholders' equity relating to fixed income securities and the inclusion of statutory non-admitted assets.

In addition to the typical adjustments from statutory to GAAP, mortgage insurance companies are required to maintain contingency loss reserves equal to 50% of premiums earned under SSAP and principles prescribed by the OCI, and such amounts cannot be withdrawn for a period of ten years except as permitted by insurance regulations. With regulatory approval, a mortgage guaranty insurance company may make early withdrawals from the contingency reserve when incurred losses exceed 35% of net premiums earned in a calendar year. For the year ended 2018, MGIC's losses incurred were 4% of net premiums earned. Changes in contingency loss reserves impact the statutory statement of operations. Contingency loss reserves are not reflected as liabilities under GAAP and changes in contingency loss reserves do not impact the GAAP statements of operations.

The statutory net income loss, policyholders' surplus and contingency reserve liability of the insurance subsidiaries of our holding company are show in table 14.1 below. The surplus amounts included in the following table are the combined policyholders' surplus of our insurance operations as utilized in our risk-to-capital calculations.



Statutory financial information of holding company and insurance subsidiaries
Table	14.1
		As of and for the Years Ended December 31,
(In thousands)		2018		2017		2016
Statutory net income		$	375,484	$	310,776	$	106,326
Statutory policyholders' surplus		1,683,058		1,622,115		1,506,475
Contingency reserve		2,442,996		1,896,701		1,360,088

The surplus contributions made to MGIC, dividends paid by MGIC, and distributions from other insurance subsidiaries to us, are shown in table 14.2 below.



Surplus contributions and dividends of insurance subsidiaries
Table	14.2
		Years Ended December 31,
(In thousands)		2018		2017	2016
Additions to the surplus of MGIC from parent company funds		$	—	—	36,025
Dividends paid by MGIC to the parent company		$	220,000	140,000	64,000
Distributions from other insurance subsidiaries to the parent company		$	—	—	52,001

STATUTORY CAPITAL REQUIREMENTS

The insurance laws of 16 jurisdictions, including Wisconsin, our domiciliary state, require a mortgage insurer to maintain a minimum amount of statutory capital relative to the RIF (or a similar measure) in order for the mortgage insurer to continue to write new business. We refer to these requirements as the “State Capital Requirements” and, together with the GSE Financial Requirements, the “Financial Requirements.” While they vary among jurisdictions, the most common State Capital Requirements allow for a maximum risk-to-capital ratio of 25 to 1. A risk-to-capital ratio will increase if (i) the percentage decrease in capital exceeds the percentage decrease in insured risk, or (ii) the percentage increase in capital is less than the percentage increase in insured risk. Wisconsin does not regulate capital by using a risk-to-capital measure but instead requires a minimum policyholder position ("MPP"). The “policyholder position” of a mortgage insurer is its net worth or surplus, contingency reserve and a portion of the reserves for unearned premiums.

At December 31, 2018, MGIC’s risk-to-capital ratio was 9.0 to 1, below the maximum allowed by the jurisdictions with State Capital Requirements and its policyholder position was $2.6 billion above the required MPP of $1.3 billion. In calculating our risk-to-capital ratio and MPP, we are allowed full credit for the risk ceded under our quota share reinsurance transactions with unaffiliated reinsurers. It is possible that under the revised State Capital Requirements discussed below, MGIC will not be allowed full credit for the risk ceded to the reinsurers. If MGIC is not allowed an agreed level of credit under either the State Capital Requirements or the PMIERs, MGIC may terminate the reinsurance agreement, without penalty. At this time, we expect MGIC to continue to comply with the current State Capital Requirements; however, you should read the rest of these financial statement footnotes for information about matters that could negatively affect such compliance.

At December 31, 2018, the risk-to-capital ratio of our combined insurance operations (which includes a reinsurance affiliate) was 9.8 to 1. Reinsurance transactions with our affiliate permit MGIC to write insurance with a higher coverage percentage than it could on its own under certain state-specific requirements.

The NAIC plans to revise the minimum capital and surplus requirements for mortgage insurers that are provided for in its Mortgage Guaranty Insurance Model Act. In May 2016, a working group of state regulators released an exposure draft of a risk-based capital framework to establish capital requirements for mortgage insurers, although no date has been established by which the NAIC must propose revisions to the capital requirements and certain items have not yet been completely addressed by the framework, including the treatment of ceded risk, minimum capital floors, and action level triggers. Currently we believe that the PMIERs contain the more restrictive capital requirements than the draft Mortgage Guaranty Insurance Model Act in most circumstances.

While MGIC currently meets the State Capital Requirements of Wisconsin and all other jurisdictions, it could be prevented from writing new business in the future in all jurisdictions if it fails to meet the State Capital Requirements of Wisconsin, or it could be prevented from writing new business in a particular jurisdiction if it fails to meet the State Capital Requirements of that jurisdiction and in each case MGIC does not obtain a waiver of such requirements. It is possible that regulatory action by one or more jurisdictions, including those that do not have specific State Capital Requirements, may prevent MGIC from continuing to write new insurance in such jurisdictions. If we are unable to write business in all jurisdictions, lenders may be unwilling to procure insurance from us anywhere. In addition, a lender’s assessment of the future ability of our insurance operations to meet the State Capital Requirements or the PMIERs may affect its willingness to procure insurance from us. A possible future failure by MGIC to meet the State Capital Requirements or the PMIERs will not necessarily mean that MGIC lacks sufficient resources to pay claims on its insurance liabilities. While we believe MGIC has sufficient claims paying resources to meet its claim obligations on its IIF on a timely basis, you should read the rest of these financial statement footnotes for information about matters that could negatively affect MGIC’s claims paying resources.

DIVIDEND RESTRICTIONS

In 2018, MGIC paid a total of $220 million in dividends to our holding company, and we expect MGIC to continue to pay quarterly dividends. In 2016, distributions of $52 million were paid to our holding company from other insurance subsidiaries. These distributions were completed in conjunction with the transfer of risk and the final dissolution of those insurance entities during 2016. Our holding company subsequently contributed the majority of the funds to MGIC in relation to the transfer of risk.

MGIC is subject to statutory regulations as to payment of dividends. The maximum amount of dividends that MGIC may pay in any twelve-month period without regulatory approval by the OCI is the lesser of adjusted statutory net income or 10% of statutory policyholders' surplus as of the preceding calendar year end. Adjusted statutory net income is defined for this purpose to be the greater of statutory net income, net of realized investment gains, for the calendar year preceding the date of the dividend or statutory net income, net of realized investment gains, for the three calendar years preceding the date of the dividend less dividends paid within the first two of the preceding three calendar years. The OCI recognizes only statutory accounting principles prescribed, or practices permitted, by the State of Wisconsin for determining and reporting the financial condition and results of operations of an insurance company. The OCI has adopted certain prescribed accounting practices that differ from those found in other states. Specifically, Wisconsin domiciled companies record changes in the contingency reserves through the income statement as a change in underwriting deduction. As a result, in periods in which MGIC is increasing contingency reserves, statutory net income is reduced. For the year ended December 31, 2018, MGIC’s increase in contingency reserves was $484 million and statutory net income was $325 million. As of December 31, 2018, MGIC's statutory policyholders' surplus was $1,682 million.

Share-based Compensation Plans

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-based Compensation Plans



NOTE 15		Share-based Compensation Plans

We have an omnibus incentive plan that was adopted on April 23, 2015. The purpose of the 2015 plan is to motivate and incent performance by, and to retain the services of, key employees and non-employee directors through receipt of equity-based and other incentive awards under the plan. The maximum number of shares of stock that can be awarded under the 2015 plan is 10.0 million. Awards issued under the plan that are subsequently forfeited will not count against the limit on the maximum number of shares that may be issued under the plan. The 2015 plan provides for the award of stock options, stock appreciation rights, restricted stock and restricted stock units, as well as cash incentive awards. No awards may be granted after April 23, 2025 under the 2015 plan. The vesting provisions of options, restricted stock and restricted stock units are determined at the time of grant. At December 31, 2018, 5.1 million shares were available for future grant under the 2015 plan.

The compensation cost that has been charged against income for share-based plans was $20.9 million, $14.9 million, and $11.4 million for the years ended December 31, 2018, 2017 and 2016, respectively. The related income tax benefit recognized for share-based plans was $3.0 million, $5.2 million, and $4.0 million for the years ended December 31, 2018, 2017, and 2016, respectively.

Table 15.1 summarizes restricted stock or restricted stock unit (collectively called “restricted stock”) activity during 2018.



Restricted stock
Table	15.1
		Weighted Average Grant Date Fair Market Value		Shares
Restricted stock outstanding at December 31, 2017		$	8.78	3,300,609
Granted		15.69		1,685,264
Vested		7.81		(1,371,063	)
Forfeited		13.28		(31,304	)
Restricted stock outstanding at December 31, 2018		$	12.27	3,583,506

At December 31, 2018, the 3.6 million shares of restricted stock outstanding consisted of 2.7 million shares that are subject to performance conditions (“performance shares”) and 0.9 million shares that are subject only to service conditions (“time vested shares”). The weighted-average grant date fair value of restricted stock granted during 2017 and 2016 was $10.41 and $5.66, respectively. The fair value of restricted stock granted is the closing price of the common stock on the New York Stock Exchange on the date of grant. The total fair value of restricted stock vested during 2018, 2017 and 2016 was $19.1 million, $15.3 million, and $12.2 million, respectively.

As of December 31, 2018, there was $18.0 million of total unrecognized compensation cost related to non-vested share-based compensation agreements granted under the plans. Of this total, $12.4 million of unrecognized compensation costs relate to performance shares and $5.6 million relates to time vested shares. A portion of the unrecognized costs associated with the performance shares may or may not be recognized in future periods, depending upon whether or not the performance and service conditions are met. The cost associated with the time vested shares is expected to be recognized over a weighted-average period of 1.8 years.

Leases

12 Months Ended

Dec. 31, 2018

Leases [Abstract]

Leases



NOTE 16		Leases

We lease certain office space as well as data processing equipment and autos under operating leases that expire during the next four years. Generally, rental payments are fixed.

Table 16.1 shows minimum the future operating lease payments as of December 31, 2018.



Minimum future operating lease payments
Table	16.1
(In thousands)		Amount
2019		$	1,406
2020		1,069
2021		371
2022		161
2023 and thereafter		—
Total		$	3,007

Total rental expense under operating leases was $1.9 million in 2018, $2.0 million in 2017, and $2.1 million in 2016.

Litigation and Contingencies

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Litigation and Contingencies



NOTE 17		Litigation and Contingencies

Before paying an insurance claim, we review the loan and servicing files to determine the appropriateness of the claim amount. When reviewing the files, we may determine that we have the right to rescind coverage on the loan. We refer to insurance rescissions and denials of claims collectively as “rescissions” and variations of that term. In addition, our insurance policies generally provide that we can reduce or deny a claim if the servicer did not comply with its obligations under our insurance policy. We call such reduction of claims “curtailments.” In recent quarters, an immaterial percentage of claims received in a quarter have been resolved by rescissions. In 2017 and 2018, curtailments reduced our average claim paid by approximately 5.6% and 5.8%, respectively.

Our loss reserving methodology incorporates our estimates of future rescissions, curtailments, and reversals of rescissions and curtailments. A variance between ultimate actual rescission, curtailment, and reversal rates and our estimates, as a result of the outcome of litigation, settlements or other factors, could materially affect our losses.

When the insured disputes our right to rescind coverage or curtail claims, we generally engage in discussions in an attempt to settle the dispute. If we are unable to reach a settlement, the outcome of a dispute ultimately may be determined by legal proceedings.

Under ASC 450-20, until a liability associated with settlement discussions or legal proceedings becomes probable and can be reasonably estimated, we consider our claim payment or rescission resolved for financial reporting purposes and do not accrue an estimated loss. Where we have determined that a loss is probable and can be reasonably estimated we have recorded our best estimate of our probable loss.

In addition to matters for which we have recorded a probable loss, we are involved in other discussions and/or proceedings with insureds with respect to our claims paying practices. Although it is reasonably possible that when these matters are resolved we will not prevail in all cases, we are unable to make a reasonable estimate or range of estimates of the potential liability. We estimate the maximum exposure associated with matters where a loss is reasonably possible to be approximately $279 million. This estimate of maximum exposure is based upon currently available information and is subject to significant judgment, numerous assumptions and known and unknown uncertainties. The matters underlying the estimate of maximum exposure will change from time to time. This estimate of our maximum exposure does not include interest or consequential or exemplary damages.

Mortgage insurers, including MGIC, have been involved in litigation and regulatory actions related to alleged violations of the anti-referral fee provisions of the Real Estate Settlement Procedures Act, which is commonly known as RESPA, and the notice provisions of the Fair Credit Reporting Act, which is commonly known as FCRA.

While these proceedings in the aggregate have not resulted in material liability for MGIC, there can be no assurance that the outcome of future proceedings, if any, under these laws would not have a material adverse effect on us. In addition, various regulators, including the CFPB, state insurance commissioners and state attorneys general may bring other actions seeking various forms of relief in connection with alleged violations of RESPA. The insurance law provisions of many states prohibit paying for the referral of insurance business and provide various mechanisms to enforce this prohibition. While we believe our practices are in conformity with applicable laws and regulations, it is not possible to predict the eventual scope, duration or outcome of any such reviews or investigations nor is it possible to predict their effect on us or the mortgage insurance industry.

Through a non-insurance subsidiary, we utilize our underwriting skills to provide an outsourced underwriting service to our customers known as contract underwriting. As part of the contract underwriting activities, that subsidiary is responsible for the quality of the underwriting decisions in accordance with the terms of the contract underwriting agreements with customers. That subsidiary may be required to provide certain remedies to its customers if certain standards relating to the quality of our underwriting work are not met, and we have an established reserve for such future obligations. Claims for remedies may be made a number of years after the underwriting work was performed. The related contract underwriting remedy expense for each of the years ended December 31, 2018, 2017, and 2016, was immaterial to our consolidated financial statements.

In addition to the matters described above, we are involved in other legal proceedings in the ordinary course of business. In our opinion, based on the facts known at this time, the ultimate resolution of these ordinary course legal proceedings will not have a material adverse effect on our financial position or consolidated results of operations.

Unaudited Quarterly Financial Data

12 Months Ended

Dec. 31, 2018

Quarterly Financial Information Disclosure [Abstract]

Unaudited Quarterly Financial Data



NOTE 18		Unaudited Quarterly Financial Data



Unaudited quarterly financial data - current year:
Table:	18.1a
2018:		Quarter												Full
(In thousands, except per share data)		First			Second			Third			Fourth			Year
Net premiums earned		$	232,107		$	246,964		$	250,426		$	245,665		$	975,162
Investment income, net of expenses		32,121			34,502			36,380			38,328			141,331
Realized (losses) gains		(329		)	(1,897		)	1,114			(241		)	(1,353		)
Other revenue		1,871			2,431			2,525			1,881			8,708
Loss incurred, net		23,850			(13,455		)	(1,518		)	27,685			36,562
Underwriting and other expenses, net		61,895			57,933			60,069			63,239			243,136
Provision for income tax		36,388			50,708			49,994			36,963			174,053
Net income		143,637			186,814			181,900			157,746			670,097
Income per share ^{(a) (b)}:
Basic		0.39			0.51			0.50			0.44			1.83
Diluted		0.38			0.49			0.49			0.43			1.78



Unaudited quarterly financial statements - prior year:
Table:	18.1b
2017:		Quarter												Full
(In thousands, except per share data)		First			Second			Third			Fourth			Year
Net premiums earned		$	229,103		$	231,136		$	237,083		$	237,425		$	934,747
Investment income, net of expenses		29,477			29,716			30,402			31,276			120,871
Realized gains (losses)		(125		)	(52		)	(50		)	458			231
Other revenue		2,425			2,512			2,925			2,343			10,205
Loss incurred, net		27,619			27,339			29,747			(30,996		)	53,709
Underwriting and other expenses, net		59,304			55,292			56,146			57,042			227,784
Loss on debt extinguishment		—			65			—			—			65
Provision for income tax		84,159			61,994			64,440			218,142			428,735
Net income		89,798			118,622			120,027			27,314			355,761
Income per share^{(a) (b)}:
Basic		0.26			0.32			0.32			0.07			0.98
Diluted		0.24			0.31			0.32			0.07			0.95


^(a)	Due to the use of weighted average shares outstanding when calculating earnings per share, the sum of the quarterly per share data may not equal the per share data for the year.


^(b)	In periods where convertible debt instruments are dilutive to earnings per share the “if-converted” method of computing diluted EPS requires an interest expense adjustment, net of tax, to net income available to shareholders. See Note 4 – “Earnings Per Share” for further discussion on our calculation of diluted EPS.

SCHEDULE I - SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES

12 Months Ended

Dec. 31, 2018

Summary of Investments, Other than Investments in Related Parties [Abstract]

SCHEDULE I - SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES



SCHEDULE I — Summary of investments - Other than investments in related parties - December 31, 2018
(In thousands) Type of Investment	Amortized Cost		Fair Value		Amount at which shown in the balance sheet
Fixed income:
Bonds:
United States Government and government agencies and authorities	$	167,655	$	167,176	$	167,176
States, municipalities and political subdivisions	1,701,826		1,720,100		1,720,100
Public utilities	212,584		208,381		208,381
Asset-backed securities	111,953		112,033		112,033
Collateralized loan obligations	310,587		305,295		305,295
Mortgage-backed	465,590		446,621		446,621
All other corporate bonds	2,226,589		2,192,381		2,192,381
Total fixed income	5,196,784		5,151,987		5,151,987

Equity securities:
Common stocks:
Industrial, miscellaneous and all other	3,993		3,932		3,932
Total equity securities	3,993		3,932		3,932

Total investments	$	5,200,777	$	5,155,919	$	5,155,919

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT

12 Months Ended

Dec. 31, 2018

Condensed Financial Information of Parent Company Only Disclosure [Abstract]

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT



SCHEDULE II - Condensed Financial Information of Registrant Condensed Balance Sheets Parent Company Only
	December 31,
(In thousands)	2018			2017
ASSETS
Fixed income, available-for-sale, at fair value (amortized cost, 2018 – $203,743; 2017 – $195,846)	$	201,507		$	194,061
Cash and cash equivalents	46,502			22,247
Investment in subsidiaries, at equity in net assets	3,981,970			3,567,034
Accounts receivable - affiliates	1,396			1,414
Income taxes - current and deferred	186,561			192,570
Accrued investment income	2,020			1,941
Other assets	740			1,275
Total assets	$	4,420,696		$	3,980,542

LIABILITIES AND SHAREHOLDERS' EQUITY
Liabilities:
Senior notes	$	419,713		$	418,560
Convertible junior subordinated debentures	389,522			389,522
Accrued interest	17,930			17,934
Other liabilities	11,640			—
Total liabilities	838,805			826,016

Shareholders’ equity:
Common stock, (one dollar par value, shares authorized 1,000,000; shares issued 2018 – 371,353; 2017 – 370,567; outstanding 2018 – 355,371; 2017 – 370,567)	371,353			370,567
Paid-in capital	1,862,536			1,850,582
Treasury stock (shares at cost 2018 – 15,982)	(175,059		)	—
Accumulated other comprehensive loss, net of tax	(124,214		)	(43,783		)
Retained earnings	1,647,275			977,160
Total shareholders’ equity	3,581,891			3,154,526
Total liabilities and shareholders’ equity	$	4,420,696		$	3,980,542

See accompanying supplementary notes to Parent Company condensed financial statements.

MGIC INVESTMENT CORPORATION



SCHEDULE II - Condensed Financial Information of Registrant Condensed Statements of Operations Parent Company Only
	Years Ended December 31,
(In thousands)	2018			2017			2016
Revenues:
Investment income, net of expenses	$	4,685		$	3,177		$	3,807
Net realized investment (losses) gains	(532		)	(13		)	646
Total revenues	4,153			3,164			4,453

Expenses:
Operating expenses	637			642			1,409
Interest expense	61,930			65,972			64,598
Loss on debt extinguishment	—			65			82,234
Total expenses	62,567			66,679			148,241
Loss before tax	(58,414		)	(63,515		)	(143,788		)
(Benefit from) provision for income taxes	(13,517		)	95,517			(52,575		)
Equity in net income of subsidiaries	714,994			514,793			433,730
Net income	670,097			355,761			342,517
Other comprehensive (loss) income, net of tax	(80,413		)	41,739			(14,220		)
Comprehensive income	$	589,684		$	397,500		$	328,297

See accompanying supplementary notes to Parent Company condensed financial statements.

MGIC INVESTMENT CORPORATION



SCHEDULE II - Condensed Financial Information of Registrant Condensed Statements of Cash Flows Parent Company Only
	Years Ended December 31,
(In thousands)	2018			2017			2016
Cash flows from operating activities:
Net income	$	670,097		$	355,761		$	342,517
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of subsidiaries	(714,994		)	(514,793		)	(433,730		)
Dividends received from subsidiaries	199,692			110,145			64,000
Deferred tax (benefit) expense	(11,756		)	96,741			(55,988		)
Loss on debt extinguishment	—			65			82,234
Other	24,303			18,716			16,722
Change in certain assets and liabilities:
Accounts receivable - affiliates	18			(634		)	158
Income taxes receivable	17,859			297			3,602
Accrued investment income	112			(192		)	1,951
Accrued interest	(4		)	(2,819		)	6,811
Net cash provided by operating activities	185,327			63,287			28,277
Cash flows from investing activities:
Capital distributions from subsidiaries	—			—			51,987
Capital contributions to subsidiaries	—			—			(36,025		)
Purchases of investments	(83,003		)	(97,091		)	(194,751		)
Proceeds from sales of investments	93,481			176,960			330,142
Net cash provided by investing activities	10,478			79,869			151,353
Cash flows from financing activities:
Proceeds from revolving credit facility	—			150,000			—
Repayment of revolving credit facility	—			(150,000		)	—
Net proceeds from issuance of long-term debt	—			—			418,094
Repurchase of convertible senior notes	—			(150,124		)	(426,191		)
Repurchase of common stock	(163,419		)	—			(147,127		)
Payment of debt issuance costs	—			(1,630		)	(1,127		)
Payment of withholding taxes related to share-based compensation net share settlement	(8,131		)	(6,821		)	(5,030		)
Net cash used in financing activities	(171,550		)	(158,575		)	(161,381		)
Net increase (decrease) in cash and cash equivalents	24,255			(15,419		)	18,249
Cash and cash equivalents at beginning of year	22,247			37,666			19,417
Cash and cash equivalents at end of year	$	46,502		$	22,247		$	37,666

See accompanying supplementary notes to Parent Company condensed financial statements.

SCHEDULE II — CONDENSED FINANCIAL INFORMATION OF REGISTRANT

PARENT COMPANY ONLY

SUPPLEMENTARY NOTES

Note A

The accompanying Parent Company financial statements should be read in conjunction with the consolidated financial statements and notes to consolidated financial statements appearing this annual report.

Note B

Our insurance subsidiaries are subject to statutory regulations as to maintenance of policyholders’ surplus and payment of dividends. The maximum amount of dividends that the insurance subsidiaries may pay in any twelve-month period without regulatory approval by the OCI is the lesser of adjusted statutory net income or 10% of statutory policyholders’ surplus as of the preceding calendar year end. Adjusted statutory net income is defined for this purpose to be the greater of statutory net income, net of realized investment gains, for the calendar year preceding the date of the dividend or statutory net income, net of realized investment gains, for the three calendar years preceding the date of the dividend less dividends paid within the first two of the preceding three calendar years.

The payment of dividends from our insurance subsidiaries is the principal source of cash inflow for MGIC Investment Corporation, our holding company, other than investment income and raising capital in the public markets. The payment of dividends by our insurance subsidiaries is restricted by insurance regulation as discussed above. MGIC is the principal source of dividend-paying capacity and, in 2018, it paid a total of $220 million in dividends in cash and fixed income securities to our holding company, and we expect MGIC to continue to pay quarterly dividends. During 2017, MGIC paid a total of $140 million in dividends in cash and fixed income securities to our holding company. During 2016, MGIC paid a total of $64 million in dividends; and other insurance subsidiaries paid distributions of $52 million to our holding company. These distributions were completed in conjunction with the transfer of risk and the final dissolution of those insurance entities during 2016. Our holding company subsequently contributed the majority of the funds, approximately $36 million, to MGIC in relation to the transfer of risk. No contributions were made to our insurance subsidiaries in 2018 or 2017.

Note C

The senior notes and convertible junior subordinated debentures ("9% Debentures"), discussed in Note 7 – “Debt” to our consolidated financial statements, are obligations of MGIC Investment Corporation, our holding company, and not of its subsidiaries. MGIC owns $132.7 million in aggregate principal of the 9% Debentures. The 9% Debentures owned by MGIC remain obligations of our holding company. For GAAP accounting purposes, the 9% Debentures owned by MGIC are eliminated in our consolidated financial statements.

- Definition

The entire disclosure for condensed financial information, including the financial position, cash flows, and the results of operations of the registrant (parent company) as of the same dates or for the same periods for which audited consolidated financial statements are being presented. Alternatively, the details of this disclosure can be reported by the specific parent company taxonomy elements, indicating the appropriate date and period contexts in an instance document.

+ References + Details

SCHEDULE IV - REINSURANCE

12 Months Ended

Dec. 31, 2018

Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]

SCHEDULE IV - REINSURANCE



SCHEDULE IV — Reinsurance Mortgage Insurance Premiums Earned Years Ended December 31, 2018, 2017 and 2016

(Dollars in thousands)	Gross Amount		Ceded to Other Companies		Assumed From Other Companies		Net Amount		Percentage of Amount Assumed to Net
Years ended December 31,
2018	$	1,084,748	$	111,391	$	1,805	$	975,162	0.2	%
2017	1,059,973		125,735		509		934,747		0.1	%
2016	1,058,545		133,981		662		925,226		0.1	%

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Basis of presentation

Reclassifications

Certain reclassifications to 2017 and 2016 amounts have been made in the accompanying consolidated financial statements to conform to the 2018 presentation.

Cash and Cash Equivalents

We consider money market funds and investments with original maturities of three months or less to be cash equivalents.

Restricted Cash and Cash Equivalents

Restricted cash and cash equivalents consists of cash and money market funds held in trusts for the benefit of contractual counterparties under reinsurance agreements.

Fair value measurements

Valuation process

Valuation hierarchy

The three levels are defined as follows.



è	Level 1	Quoted prices for identical instruments in active markets that we can access. Financial assets using Level 1 inputs primarily include U.S. Treasury securities, money market funds, and certain equity securities.
è	Level 2	Quoted prices for similar instruments in active markets that we can access; quoted prices for identical or similar instruments in markets that are not active; and inputs, other than quoted prices, that are observable in the marketplace for the instrument. The observable inputs are used in valuation models to calculate the fair value of the instruments. Financial assets using Level 2 inputs primarily include obligations of U.S. government corporations and agencies, corporate bonds, mortgage-backed securities, asset-backed securities, and most municipal bonds. The independent pricing sources used for our Level 2 investments vary by type of investment. See Note 6 - "Fair Value Measurements" for further information.
è	Level 3	Valuations derived from valuation techniques in which one or more significant inputs or value drivers are unobservable or, from par values due to restrictions on certain securities that require them to be redeemed or sold only to the security issuer at par value. The inputs used to derive the fair value of Level 3 securities reflect our own assumptions about the assumptions a market participant would use in pricing an asset or liability. Financial assets using Level 3 inputs include obligations of U.S. states and political subdivisions and certain equity securities (2017 only). Our non-financial assets that are classified as Level 3 securities consist of real estate acquired through claim settlement. The fair value of real estate acquired is the lower of our acquisition cost or a percentage of the appraised value. The percentage applied to the appraised value is based upon our historical sales experience adjusted for current trends.

Investments

Unrealized losses and OTTI



è	our intent to sell the security or whether it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis;
è	the present value of the discounted cash flows we expect to collect compared to the amortized cost basis of the security;
è	extent and duration of the decline;
è	failure of the issuer to make scheduled interest or principal payments;
è	change in rating below investment grade; and
è	adverse conditions specifically related to the security, an industry, or a geographic area.

Home office and equipment

Deferred Insurance Policy Acquisition Costs

Loss Reserves

Premium Deficiency Reserve

Share-Based Compensation

Earnings per Share

For purposes of calculating basic and diluted EPS, vested restricted stock and RSUs are considered outstanding.

Recent accounting and reporting developments

Accounting standards effective in 2018, or early adopted, and relevant to our financial statements



Standard / Interpretation
Table	3.1
				Effective date
Amended Standards
ASC 230		Statement of Cash Flows
		•	ASU 2016-18 - Restricted Cash	January 1, 2018
ASC 718		Compensation - Stock Compensation
		•	ASU 2017-09 - Scope of Modification Accounting	January 1, 2018
ASC 310		Receivables - Nonrefundable Fees and Other Costs
		•	ASU 2017-08 - Premium Amortization on Purchased Callable Debt Securities	January 1, 2019
ASC 715		Compensation - Retirement Benefits
		•	ASU 2017-07 - Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost	January 1, 2018
ASC 825		Financial Instruments - Overall
		•	ASU 2016-01 - Recognition and Measurement of Financial Assets and Financial Liabilities	January 1, 2018

Statement of Cash Flows - Restricted Cash



è	Adoption impact: The statements of cash flows presented for the three years ended December 31, 2018 are in accordance with the guidance of this updated standard.

Stock Compensation - Scope of Modification Accounting



è	Adoption impact: The adoption of this guidance had no impact on our consolidated financial statements or disclosures.

Premium Amortization on Purchased Callable Debt Securities



è	Adoption impact: We adopted this guidance as of January 1, 2018 with no impact to our consolidated financial statements or disclosures as our accounting policy adhered to the updated guidance.

Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost



è	Adoption impact: The adoption of this guidance had no impact on our consolidated financial statements or disclosures as the service cost component is reported in the same financial statement caption as other compensation costs and we do not present a subtotal of income outside of income from operations. The service cost component of our benefit plans is disclosed in Note 11 - “Benefit Plans” to our consolidated financial statements.

Recognition and Measurement of Financial Assets and Financial Liabilities



è	Adoption impact: The adoption of this guidance resulted in an immaterial cumulative effect adjustment to our 2018 beginning accumulated other comprehensive (loss) income and retained earnings to recognize unrealized gains on equity investments. At December 31, 2017, equity investments were classified as available-for-sale on the consolidated balance sheet. Upon adoption, the updated guidance eliminated the available-for-sale balance sheet classification for equity securities.



è	Adoption impact: At December 31, 2018, the value of our investment in FHLB stock, which is carried at cost, is presented within “Other invested assets” on our consolidated balance sheet.

PROSPECTIVE ACCOUNTING STANDARDS

Table 3.2 shows the relevant new amendments to accounting standards, which are not yet effective or adopted.



Standard / Interpretation
Table	3.2
				Effective date
Amended Standards
ASC 326		Financial Instruments - Credit Losses
		•	ASU 2016-13 - Measurement of Credit Losses on Financial Instruments	January 1, 2020
ASC 820		Fair Value Measurement
		•	ASU 2018-13 - Changes to the Disclosure Requirements for Fair Value Measurements	January 1, 2020
ASC 715		Compensation - Retirement Benefits
		•	ASU 2018-14 - Changes to the Disclosure Requirements for Defined Benefit Plans	January 1, 2021

Measurement of Credit Losses on Financial Instruments

Changes to the Disclosure Requirements for Fair Value Measurement

Changes to the Disclosure Requirements for Defined Benefit Plans

Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Schedule of Recent Accounting and Reporting Developments



Standard / Interpretation
Table	3.1
				Effective date
Amended Standards
ASC 230		Statement of Cash Flows
		•	ASU 2016-18 - Restricted Cash	January 1, 2018
ASC 718		Compensation - Stock Compensation
		•	ASU 2017-09 - Scope of Modification Accounting	January 1, 2018
ASC 310		Receivables - Nonrefundable Fees and Other Costs
		•	ASU 2017-08 - Premium Amortization on Purchased Callable Debt Securities	January 1, 2019
ASC 715		Compensation - Retirement Benefits
		•	ASU 2017-07 - Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost	January 1, 2018
ASC 825		Financial Instruments - Overall
		•	ASU 2016-01 - Recognition and Measurement of Financial Assets and Financial Liabilities	January 1, 2018

Schedule of Prospective Accounting Standards, Not Yet Effective Or Adopted

Table 3.2 shows the relevant new amendments to accounting standards, which are not yet effective or adopted.



Standard / Interpretation
Table	3.2
				Effective date
Amended Standards
ASC 326		Financial Instruments - Credit Losses
		•	ASU 2016-13 - Measurement of Credit Losses on Financial Instruments	January 1, 2020
ASC 820		Fair Value Measurement
		•	ASU 2018-13 - Changes to the Disclosure Requirements for Fair Value Measurements	January 1, 2020
ASC 715		Compensation - Retirement Benefits
		•	ASU 2018-14 - Changes to the Disclosure Requirements for Defined Benefit Plans	January 1, 2021

Earnings per Share (Tables)

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Calculation of earnings (loss) per share

Table 4.1 reconciles basic and diluted EPS amounts:



Earnings per share
Table	4.1
		Years Ended December 31,
(In thousands, except per share data)		2018		2017		2016
Basic earnings per share:
Net income		$	670,097	$	355,761	$	342,517
Weighted average common shares outstanding - basic		365,406		362,380		342,890
Basic earnings per share		$	1.83	$	0.98	$	1.00
Diluted earnings per share:
Net income		$	670,097	$	355,761	$	342,517
Interest expense, net of tax ⁽¹⁾:
2% Notes		—		907		6,111
5% Notes		—		1,709		6,362
9% Debentures		18,264		15,027		15,893
Diluted income available to common shareholders		$	688,361	$	373,404	$	370,883
Weighted-average shares - basic		365,406		362,380		342,890
Effect of dilutive securities:
Unvested restricted stock units		1,644		1,493		1,470
2% Notes		—		8,317		54,450
5% Notes		—		3,548		13,107
9% Debentures		19,028		19,028		20,075
Weighted average common shares outstanding - diluted		386,078		394,766		431,992
Diluted income per share		$	1.78	$	0.95	$	0.86


⁽¹⁾	Interest expense for the years ended December 31, 2018, 2017 and 2016 has been tax effected at a rate of 21%, 35%, and 35%, respectively.

Investments (Tables)

12 Months Ended

Dec. 31, 2018

Investments [Abstract]

Amortized cost, gross unrealized gains and losses and fair value of investment portfolio

The amortized cost, gross unrealized gains and losses and fair value of our fixed income securities as of December 31, 2018 and 2017 are shown below:



Details of fixed income investment securities by category as of December 31, 2018
Table	5.1a
(In thousands)		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	167,655	$	597	$	(1,076	)	$	167,176
Obligations of U.S. states and political subdivisions		1,701,826		29,259		(10,985		)	1,720,100
Corporate debt securities		2,439,173		2,103		(40,514		)	2,400,762
ABS		111,953		226		(146		)	112,033
RMBS		189,238		32		(10,309		)	178,961
CMBS		276,352		888		(9,580		)	267,660
CLOs		310,587		2		(5,294		)	305,295
Total fixed income securities		$	5,196,784	$	33,107	$	(77,904	)	$	5,151,987



Details of fixed income investment securities by category as of December 31, 2017
Table	5.1b
(In thousands)		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	179,850	$	274	$	(1,278	)	$	178,846
Obligations of U.S. states and political subdivisions		2,105,063		56,210		(8,749		)	2,152,524
Corporate debt securities		2,065,475		10,532		(9,169		)	2,066,838
ABS		4,925		—		(2		)	4,923
RMBS		189,153		60		(7,364		)	181,849
CMBS		301,014		1,204		(4,906		)	297,312
CLOs		100,798		304		(79		)	101,023
Total fixed income securities		$	4,946,278	$	68,584	$	(31,547	)	$	4,983,315


⁽¹⁾	There were no OTTI losses recorded in other comprehensive (loss) income as of December 31, 2018 and 2017.

Amortized cost and fair values of debt securities by contractual maturity



Fixed income securities maturity schedule
Table	5.2
		December 31, 2018
(In thousands)		Amortized Cost		Fair Value
Due in one year or less		$	484,485	$	482,919
Due after one year through five years		1,652,638		1,632,494
Due after five years through ten years		1,011,237		996,335
Due after ten years		1,160,294		1,176,290
		4,308,654		4,288,038

ABS		111,953		112,033
RMBS		189,238		178,961
CMBS		276,352		267,660
CLOs		310,587		305,295
Total as of December 31, 2018		$	5,196,784	$	5,151,987

Cost and fair value of investments in equity securities

Details of equity investment securities as of December 31, 2018

Table

5.3a

(In thousands)

Cost

Gross gains

Gross losses

Fair Value

Equity securities

3,993

(72

)

3,932

Details of equity investment securities as of December 31, 2017

Table

5.3b

(In thousands)

Cost

Gross gains

Gross losses

Fair Value

Equity securities

7,223

(16

)

7,246

Aging of the fair values of securities in an unrealized loss position



Unrealized loss aging for securities by type and length of time as of December 31, 2018
Table	5.4a
		Less Than 12 Months					12 Months or Greater					Total
(In thousands)		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	23,710	$	(15	)	$	69,146	$	(1,061	)	$	92,856	$	(1,076	)
Obligations of U.S. states and political subdivisions		316,655		(3,875		)	358,086		(7,110		)	674,741		(10,985		)
Corporate debt securities		1,272,279		(18,130		)	785,627		(22,384		)	2,057,906		(40,514		)
ABS		51,324		(146		)	—		—			51,324		(146		)
RMBS		24		—			178,573		(10,309		)	178,597		(10,309		)
CMBS		65,704		(1,060		)	163,272		(8,520		)	228,976		(9,580		)
CLOs		296,497		(5,294		)	—		—			296,497		(5,294		)
Total		$	2,026,193	$	(28,520	)	$	1,554,704	$	(49,384	)	$	3,580,897	$	(77,904	)



Unrealized loss aging for securities by type and length of time as of December 31, 2017
Table	5.4b
		Less Than 12 Months					12 Months or Greater					Total
(In thousands)		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	144,042	$	(796	)	$	31,196	$	(482	)	$	175,238	$	(1,278	)
Obligations of U.S. states and political subdivisions		505,311		(3,624		)	211,684		(5,125		)	716,995		(8,749		)
Corporate debt securities		932,350		(4,288		)	200,716		(4,881		)	1,133,066		(9,169		)
ABS		4,923		(2		)	—		—			4,923		(2		)
RMBS		14,979		(280		)	166,329		(7,084		)	181,308		(7,364		)
CMBS		51,096		(358		)	138,769		(4,548		)	189,865		(4,906		)
CLOs		14,243		(7		)	3,568		(72		)	17,811		(79		)
Equity securities		226		(2		)	431		(14		)	657		(16		)
Total		$	1,667,170	$	(9,357	)	$	752,693	$	(22,206	)	$	2,419,863	$	(31,563	)

Net investment income

The source of net investment income is shown in table 5.5 below.



Net investment income
Table	5.5
(In thousands)		2018			2017			2016
Fixed income securities		$	140,539		$	122,105		$	112,513
Equity securities		228			206			182
Cash equivalents		3,423			1,447			754
Other		816			620			433
Investment income		145,006			124,378			113,882
Investment expenses		(3,675		)	(3,507		)	(3,216		)
Net investment income		$	141,331		$	120,871		$	110,666

Change in unrealized gains (losses) of investments

The change in unrealized gains (losses) of investments is shown in table 5.6 below.



Change in unrealized gains (losses)
Table	5.6
(In thousands)		2018			2017			2016
Fixed income securities		$	(81,834	)	$	69,026		$	(5,403	)
Equity securities		—			39			(36		)
Other		—			(13		)	14
Change in unrealized gains/losses		$	(81,834	)	$	69,052		$	(5,425	)

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair value measurements for items measured at fair value

Assets carried at fair value included those listed, by hierarchy level, in the following tables as of December 31, 2018 and 2017:



Assets carried at fair value by hierarchy level as of December 31, 2018
Table	6.1a
(In thousands)		Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	167,176	$	42,264	$	124,912	$	—
Obligations of U.S. states and political subdivisions		1,720,100		—		1,720,087		13
Corporate debt securities		2,400,762		—		2,400,762		—
ABS		112,033		—		112,033		—
RMBS		178,961		—		178,961		—
CMBS		267,660		—		267,660		—
CLOs		305,295		—		305,295		—
Total fixed income securities		5,151,987		42,264		5,109,710		13
Equity securities		3,932		3,932		—		—
Other ⁽¹⁾		96,403		96,403		—		—
Real estate acquired ⁽²⁾		14,535		—		—		14,535
Total		$	5,266,857	$	142,599	$	5,109,710	$	14,548



Assets carried at fair value by hierarchy level as of December 31, 2017
Table	6.1b
(In thousands)		Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$	178,846	$	81,598	$	97,248	$	—
Obligations of U.S. states and political subdivisions		2,152,524		—		2,152,253		271
Corporate debt securities		2,066,838		—		2,066,838		—
ABS		4,923		—		4,923		—
RMBS		181,849		—		181,849		—
CMBS		297,312		—		297,312		—
CLOs		101,023		—		101,023		—
Total fixed income securities		4,983,315		81,598		4,901,446		271
Equity securities ⁽³⁾		7,246		2,978		—		4,268
Real estate acquired ⁽²⁾		12,713		—		—		12,713
Total		$	5,003,274	$	84,576	$	4,901,446	$	17,252


⁽¹⁾	Consists of money market funds included in "Cash and Cash Equivalents" and "Restricted Cash and Cash Equivalents" on the consolidated balance sheet.


⁽²⁾	Real estate acquired through claim settlement, which is held for sale, is reported in "Other assets" on the consolidated balance sheets.


⁽³⁾	Equity securities in Level 3 are carried at cost, which approximates fair value. See "Reconciliation of Level 3 assets" below for information regarding a change in presentation of amounts previously included in Level 3 Equity securities.

Reconciliation of beginning and ending balance for assets and liabilities measured at fair value with significant unobservable inputs (level 3)



Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2018
Table	6.2a
(In thousands)		Debt Securities			Equity Securities			Total Investments			Real Estate Acquired
Balance at December 31, 2017		$	271		$	4,268		$	4,539		$	12,713
Transfers out of Level 3		—			(3,100		)	(3,100		)	—
Total realized/unrealized gains (losses):
Included in earnings and reported as net realized investment gains		—			3,663			3,663			—
Included in earnings and reported as losses incurred, net		—			—			—			(1,995		)
Purchases		—			—			—			33,912
Sales		(258		)	(4,831		)	(5,089		)	(30,095		)
Balance at December 31, 2018		$	13		$	—		$	13		$	14,535



Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2017
Table	6.2b
(In thousands)		Debt Securities			Equity Securities		Total Investments			Real Estate Acquired
Balance at December 31, 2016		$	691		$	4,268	$	4,959		$	11,748
Total realized/unrealized gains (losses):
Included in earnings and reported as losses incurred, net		—			—		—			(1,315		)
Purchases		—			—		—			34,749
Sales		(420		)	—		(420		)	(32,469		)
Balance at December 31, 2017		$	271		$	4,268	$	4,539		$	12,713



Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2016
Table	6.2c
(In thousands)		Debt Securities			Equity Securities			Total Investments			Real Estate Acquired
Balance at December 31, 2015		$	1,228		$	2,855		$	4,083		$	12,149
Total realized/unrealized gains (losses):
Included in earnings and reported as net realized investment gains		—			3,579			3,579			—
Included in earnings and reported as losses incurred, net		—			—			—			(1,142		)
Purchases		—			4,258			4,258			36,859
Sales		(537		)	(6,424		)	(6,961		)	(36,118		)
Balance at December 31, 2016		$	691		$	4,268		$	4,959		$	11,748

Schedule of carrying value and fair value of financial liabilities measured on a recurring basis

Table 6.3 compares the carrying value and fair value of our financial liabilities disclosed, but not carried, at fair value as of December 31, 2018 and 2017. The fair values of our 5.75% Notes and 9% Debentures were based on observable market prices. The fair value of the FHLB Advance was estimated using cash flows discounted at current incremental borrowing rates for similar borrowing arrangements, and in all cases they are categorized as Level 2. See Note 7 - "Debt" for a description of the financial liabilities in table 6.3.



Financial liabilities not carried at fair value
Table	6.3
		December 31, 2018				December 31, 2017
(In thousands)		Carrying Value		Fair Value		Carrying Value		Fair Value
Liabilities
FHLB Advance		$	155,000	$	150,551	$	155,000	$	152,124
5.75% Notes		419,713		425,791		418,560		465,473
9% Debentures		256,872		338,069		256,872		353,507
Total financial liabilities		$	831,585	$	914,411	$	830,432	$	971,104

Loss Reserves (Tables)

12 Months Ended

Dec. 31, 2018

Insurance Loss Reserves [Abstract]

Reconciliation of beginning and ending loss reserves

Table 8.1 provides a reconciliation of beginning and ending loss reserves for each of the past three years:



Development of reserves for losses and loss adjustment expenses
Table	8.1
(In thousands)		2018			2017			2016
Reserve at beginning of year		$	985,635		$	1,438,813		$	1,893,402
Less reinsurance recoverable		48,474			50,493			44,487
Net reserve at beginning of year		937,161			1,388,320			1,848,915

Losses incurred:
Losses and LAE incurred in respect of delinquent notices received in:
Current year		203,928			284,913			387,815
Prior years ⁽¹⁾		(167,366		)	(231,204		)	(147,658		)
Total losses incurred		36,562			53,709			240,157

Losses paid:
Losses and LAE paid in respect of delinquent notices received in:
Current year		7,298			11,267			14,823
Prior years		327,743			493,300			689,258
Reinsurance terminations		(2,009		)	301			(3,329		)
Total losses paid		333,032			504,868			700,752
Net reserve at end of year		640,691			937,161			1,388,320
Plus reinsurance recoverables		33,328			48,474			50,493
Reserve at end of year		$	674,019		$	985,635		$	1,438,813


⁽¹⁾	A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves. See table 8.2 below for more information about prior year loss development.

Prior year development of the reserves

Table 8.2 below shows the development of reserves in 2018, 2017 and 2016 for previously received delinquencies.



Reserve development on previously received delinquencies
Table	8.2
(In millions)		2018			2017			2016
Decrease in estimated claim rate on primary delinquencies		$	(213	)	$	(248	)	$	(148	)
Increase in estimated severity on primary delinquencies		29			9			9
Change in estimates related to pool reserves, LAE reserves, reinsurance and other		17			8			(9		)
Total prior year loss development ⁽¹⁾		$	(167	)	$	(231	)	$	(148	)


⁽¹⁾	A negative number for prior year loss development indicates a redundancy of prior year loss reserves.

Rollforward of delinquent inventory roll-forward



Primary delinquent inventory roll-forward
Table	8.3
		2018		2017		2016
Beginning delinquent inventory		46,556		50,282		62,633
New Notices		54,448		68,268		67,434
Cures		(60,511	)	(61,094	)	(65,516	)
Paid claims		(5,750	)	(9,206	)	(12,367	)
Rescissions and denials		(267	)	(357	)	(629	)
Other items removed from inventory		(1,578	)	(1,337	)	(1,273	)
Ending delinquent inventory		32,898		46,556		50,282

Aging of the primary default inventory

The number of consecutive months that a borrower has been delinquent is shown in the table below.



Primary delinquent inventory - consecutive months delinquent
Table	8.4
		December 31,
		2018		2017		2016
3 months or less		9,829		17,119		12,194
4 - 11 months		9,655		12,050		13,450
12 months or more⁽¹⁾		13,414		17,387		24,638
Total		32,898		46,556		50,282

3 months or less		30	%	37	%	24	%
4 - 11 months		29	%	26	%	27	%
12 months or more		41	%	37	%	49	%
Total		100	%	100	%	100	%

Primary claims received inventory included in ending delinquent inventory		809		954		1,385


⁽¹⁾	Approximately 38%, 45%, and 47% of the primary delinquent inventory delinquent for 12 consecutive months or more has been delinquent for at least 36 consecutive months as of December 31, 2018, 2017 and 2016, respectively.

Reinsurance (Tables)

12 Months Ended

Dec. 31, 2018

Reinsurance Disclosures [Abstract]

Effect of reinsurance agreements on premiums earned and losses incurred

Table 9.1 below shows the effect of all reinsurance agreements on premiums earned and losses incurred as reflected in the consolidated statements of operations.



Reinsurance
Table	9.1
		Years ended December 31,
(In thousands)		2018			2017			2016
Premiums earned:
Direct		$	1,084,748		$	1,059,973		$	1,058,545
Assumed		1,805			509			662
Ceded		(111,391		)	(125,735		)	(133,981		)
Net premiums earned		$	975,162		$	934,747		$	925,226

Losses incurred:
Direct		$	43,060		$	74,727		$	273,207
Assumed		331			183			1,138
Ceded		(6,829		)	(21,201		)	(34,188		)
Net losses incurred		$	36,562		$	53,709		$	240,157

Quota share reinsurance, excluding captive agreements

Table 9.2 provides a summary of our quota share reinsurance agreements, excluding captive agreements, for 2018, 2017 and 2016.



Quota share reinsurance
Table	9.2
		Years ended December 31,
(In thousands)		2018		2017		2016
Ceded premiums written and earned, net of profit commission ⁽¹⁾		$	108,337	$	120,974	$	125,460
Ceded losses incurred		6,543		22,336		30,201
Ceding commissions ⁽²⁾		51,201		49,321		47,629
Profit commission		147,667		125,629		112,685


⁽¹⁾	Under our QSR Transactions, premiums are ceded on an earned and received basis as defined in our agreements.


⁽²⁾	Ceding commissions are reported within Other underwriting and operating expenses, net on the consolidated statements of operations.

Schedule of Total Assets of Home Re

The following presents the total assets of Home Re as of December 31, 2018.



Home Re total assets
Table	9.3

(In thousands)		Total VIE Assets
Home Re 2018-1 Ltd.		$	318,636

The following presents the total assets of Home Re as of December 31, 2018.



Home Re total assets
Table	9.3

(In thousands)		Total VIE Assets
Home Re 2018-1 Ltd.		$	318,636

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2018

Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]

Other comprehensive income

The pretax components of our other comprehensive income (loss) and related income tax (expense) benefit for the years ended December 31, 2018, 2017 and 2016 are included in table 10.1 below.



Components of other comprehensive income (loss)
Table	10.1
(In thousands)		2018			2017			2016
Net unrealized investment (losses) gains arising during the year		$	(81,834	)	$	69,052		$	(5,425	)
Income tax benefit (expense)		17,188			(21,505		)	1,776
Net of taxes		(64,646		)	47,547			(3,649		)

Net changes in benefit plan assets and obligations		(19,958		)	(8,983		)	(14,799		)
Income tax benefit		4,191			3,144			5,179
Net of taxes		(15,767		)	(5,839		)	(9,620		)

Net changes in unrealized foreign currency translation adjustment		—			45			(1,463		)
Income tax (expense) benefit		—			(14		)	512
Net of taxes		—			31			(951		)

Total other comprehensive (loss) income		(101,792		)	60,114			(21,687		)
Total income tax benefit (expense), net		21,379			(18,375		)	7,467
Total other comprehensive (loss) income, net of tax		$	(80,413	)	$	41,739		$	(14,220	)

Reclassification out of accumulated other comprehensive income



Reclassifications from AOCL
Table	10.2
(In thousands)		2018			2017			2016
Reclassification adjustment for net realized (losses) gains included in net income ⁽¹⁾		$	(7,037	)	$	(2,580	)	$	6,207
Income tax benefit (expense)		1,477			903			(2,050		)
Net of taxes		(5,560		)	(1,677		)	4,157

Reclassification adjustment related to benefit plan assets and obligations ⁽²⁾		(2,232		)	906			1,480
Income tax benefit (expense)		469			(317		)	(518		)
Net of taxes		(1,763		)	589			962

Reclassification adjustment related to foreign currency ⁽³⁾		—			—			1,467
Income tax (expense)		—			—			(513		)
Net of taxes		—			—			954

Total reclassifications		(9,269		)	(1,674		)	9,154
Total income tax benefit (expense), net		1,946			586			(3,081		)
Total reclassifications, net of tax		$	(7,323	)	$	(1,088	)	$	6,073


⁽¹⁾	(Decreases) increases Net realized investment gains on the consolidated statements of operations.


⁽²⁾	Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations.


⁽³⁾	Increases (decreases) Other revenue on the consolidated statements of operations.

Accumulated other comprehensive income (loss)

A roll-forward of AOCL for the years ended December 31, 2018, 2017, and 2016, including amounts reclassified from AOCL, is included in table 10.3 below.



Roll-forward of AOCL
Table	10.3
(In thousands)		Net unrealized gains and losses on available-for-sale securities			Net benefit plan assets and obligations recognized in shareholders' equity			Net unrealized foreign currency translation			Total AOCL
Balance, December 31, 2015, net of tax		$	(17,148	)	$	(44,652	)	$	920		$	(60,880	)
Other comprehensive income (loss) before reclassifications		508			(8,658		)	3			(8,147		)
Less: Amounts reclassified from AOCL		4,157			962			954			6,073
Balance, December 31, 2016, net of tax		(20,797		)	(54,272		)	(31		)	(75,100		)
Other comprehensive income (loss) before reclassifications		45,870			(5,250		)	31			40,651
Less: Amounts reclassified from AOCL		(1,677		)	589			—			(1,088		)
Less: Amounts reclassified for lower enacted corporate tax rate		(2,525		)	12,947			—			10,422
Balance, December 31, 2017, net of tax		29,275			(73,058		)	—			(43,783		)
Cumulative effect of adopting the accounting standard update for financial instruments		(18		)	—			—			(18		)
Other comprehensive income (loss) before reclassifications		(70,206		)	(17,530		)	—			(87,736		)
Less: Amounts reclassified from AOCL		(5,560		)	(1,763		)	—			(7,323		)
Balance, December 31, 2018, net of tax		$	(35,389	)	$	(88,825	)	$	—		(124,214		)

Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Components of net periodic benefit cost

The following tables 11.1, 11.2, and 11.3 provide the components of aggregate annual net periodic benefit cost for each of the years ended December 31, 2018, 2017, and 2016 and changes in the benefit obligation and the funded status of the pension, supplemental executive retirement and other postretirement benefit plans as recognized in the consolidated balance sheets as of December 31, 2018 and 2017.



Components of net periodic benefit cost
Table	11.1
		Pension and Supplemental Executive Retirement Plans									Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2016			12/31/2018			12/31/2017			12/31/2016
1. Company Service Cost		$	10,530		$	9,556		$	9,130		$	1,160		$	813		$	751
2. Interest Cost		15,095			15,475			15,906			834			706			704
3. Expected Return on Assets		(22,250		)	(20,099		)	(19,508		)	(6,359		)	(5,248		)	(4,886		)
4. Other Adjustments		—			—			—			—			—			—
Subtotal		3,375			4,932			5,528			(4,365		)	(3,729		)	(3,431		)
5. Amortization of:
a. Net Transition Obligation/(Asset)		—			—			—			—			—			—
b. Net Prior Service Cost/(Credit)		(351		)	(426		)	(687		)	(4,104		)	(6,649		)	(6,649		)
c. Net Losses/(Gains)		6,937			6,169			5,856			(250		)	—			—
Total Amortization		6,586			5,743			5,169			(4,354		)	(6,649		)	(6,649		)
6. Net Periodic Benefit Cost		9,961			10,675			10,697			(8,719		)	(10,378		)	(10,080		)
7. Cost of settlements		—			—			1,277			—			—			—
8. Total Expense for Year		$	9,961		$	10,675		$	11,974		$	(8,719	)	$	(10,378	)	$	(10,080	)

Development of funded status



Development of funded status
Table	11.2
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
Actuarial Value of Benefit Obligations
1. Measurement Date		12/31/2018			12/31/2017			12/31/2018			12/31/2017
2. Accumulated Benefit Obligation		$	375,562		$	411,996		$	28,085		$	24,716

Funded Status/Asset (Liability) on the Consolidated Balance Sheet
1. Projected Benefit Obligation		$	(376,153	)	$	(417,770	)	$	(28,085	)	$	(24,716	)
2. Plan Assets at Fair Value		359,719			401,142			77,762			85,303
3. Funded Status - Overfunded/Asset		N/A			N/A			$	49,677		$	60,587
4. Funded Status - Underfunded/Liability		(16,434		)	(16,628		)	N/A			N/A



Accumulated other comprehensive income (loss)
Table	11.3
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018		12/31/2017
1. Net Actuarial (Gain)/Loss		$	110,321		$	109,904		$	939	$	(10,234	)
2. Net Prior Service Cost/(Credit)		(1,513		)	(1,850		)	2,690		(5,342		)
3. Net Transition Obligation/(Asset)		—			—			—		—
4. Total at Year End		$	108,808		$	108,054		$	3,629	$	(15,576	)

Change in projected benefit obligation

Table 11.4 shows the changes in the projected benefit obligation for 2018 and 2017.



Change in projected benefit / accumulated benefit
Table	11.4
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
1. Benefit Obligation at Beginning of Year		$	417,770		$	369,808		$	24,716		$	17,378
2. Company Service Cost		10,530			9,556			1,160			813
3. Interest Cost		15,095			15,475			834			706
4. Plan Participants' Contributions		—			—			475			395
5. Net Actuarial (Gain)/Loss due to Assumption Changes		(36,132		)	38,496			(1,209		)	5,981
6. Net Actuarial (Gain)/Loss due to Plan Experience		2,487			2,338			(692		)	924
7. Benefit Payments from Fund ⁽¹⁾		(32,674		)	(17,578		)	(1,077		)	(1,404		)
8. Benefit Payments Directly by Company		(908		)	(335		)	—			—
9. Plan Amendments		(15		)	10			3,928			—
10. Other Adjustment		—			—			(50		)	(77		)
11. Benefit Obligation at End of Year		$	376,153		$	417,770		$	28,085		$	24,716


⁽¹⁾	Includes lump sum payments of $20.9 million and $6.3 million in 2018 and 2017, respectively, from our pension plan to eligible participants, which were former employees with vested benefits.

Change in plan assets

Tables 11.5 and 11.6 shows the changes in the fair value of the net assets available for plan benefits, and changes in other comprehensive income (loss) during 2018 and 2017.



Change in plan assets
Table	11.5
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
1. Fair Value of Plan Assets at Beginning of Year		$	401,142		$	360,900		$	85,303		$	70,408
2. Company Contributions		10,908			9,435			—			—
3. Plan Participants' Contributions		—			—			475			395
4. Benefit Payments from Fund		(32,674		)	(17,578		)	(1,077		)	(1,404		)
5. Benefit Payments paid directly by Company		(908		)	(335		)	—			—
6. Actual Return on Assets		(19,583		)	48,720			(6,464		)	16,299
7. Other Adjustment		834			—			(475		)	(395		)
8. Fair Value of Plan Assets at End of Year		$	359,719		$	401,142		$	77,762		$	85,303

Change in accumulated other comprehensive income (AOCI)



Change in accumulated other comprehensive income (loss) ("AOCI")
Table	11.6
		Pension and Supplemental Executive Retirement Plans						Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2017			12/31/2018			12/31/2017
1. AOCI in Prior Year		$	108,054		$	101,575		$	(15,576	)	$	(18,079	)
2. Increase/(Decrease) in AOCI
a. Recognized during year - Prior Service (Cost)/Credit		351			426			4,104			6,649
b. Recognized during year - Net Actuarial (Losses)/Gains		(6,937		)	(6,169		)	250			—
c. Occurring during year - Prior Service Cost		(15		)	10			3,928			—
d. Occurring during year - Net Actuarial Losses/(Gains)		7,355			12,212			10,923			(4,146		)
3. AOCI in Current Year		$	108,808		$	108,054		$	3,629		$	(15,576	)

Amortizations expected to be recognized during next fiscal year

Table 11.7 shows the amount of amortization on components of net periodic benefit costs expected to be recognized during the year ending December 31, 2019.



Amortization expected to be recognized during fiscal year ending
Table	11.7
		Pension and Supplemental Executive Retirement Plans			Other Postretirement Benefits
(In thousands)		12/31/2018			12/31/2018
1. Amortization of Net Transition Obligation/(Asset)		$	—		$	—
2. Amortization of Prior Service Cost/(Credit)		(280		)	(34		)
3. Amortization of Net Losses/(Gains)		8,271			—

Actuarial assumptions

The projected benefit obligations, net periodic benefit costs and accumulated postretirement benefit obligation for the plans were determined using the following weighted average assumptions.



Actuarial assumptions
Table	11.8
		Pension and Supplemental Executive Retirement Plans				Other Postretirement Benefits
		12/31/2018		12/31/2017		12/31/2018		12/31/2017
Weighted-Average Assumptions Used to Determine
Benefit Obligations at year end
1. Discount Rate		4.40	%	3.75	%	4.25	%	3.55	%
2. Rate of Compensation Increase		3.00	%	3.00	%	N/A		N/A

Weighted-Average Assumptions Used to Determine
Net Periodic Benefit Cost for Year
1. Discount Rate		3.75	%	4.30	%	3.55	%	3.95	%
2. Expected Long-term Return on Plan Assets		5.75	%	5.75	%	7.50	%	7.50	%
3. Rate of Compensation Increase		3.00	%	3.00	%	N/A		N/A

Assumed Health Care Cost Trend Rates at year end
1. Health Care Cost Trend Rate Assumed for Next Year		N/A		N/A		6.25	%	6.50	%
2. Rate to Which the Cost Trend Rate is Assumed to Decline (Ultimate Trend Rate)		N/A		N/A		5.00	%	5.00	%
3. Year That the Rate Reaches the Ultimate Trend Rate		N/A		N/A		2024		2024

Year-end asset allocations of the plans

The year-end asset allocations of the plans are shown in table 11.9 below.



Plan assets
Table	11.9
		Pension Plan				Other Postretirement Benefits
		12/31/2018		12/31/2017		12/31/2018		12/31/2017
1. Equity Securities		23	%	21	%	100	%	100	%
2. Debt Securities		77	%	79	%	—	%	—	%
3. Total		100	%	100	%	100	%	100	%

Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]

Schedule of investment allocation strategies

The equity investments use combinations of mutual funds, ETFs, and pooled equity account structures focused on the following strategies:



Strategy	Objective	Investment types
Return seeking growth	Funded ratio improvement over the long term	●	Global quality growth
Return seeking growth	Funded ratio improvement over the long term	●	Global low volatility
Return seeking bridge	Downside protection in the event of a declining equity market	●	Enduring asset
Return seeking bridge		●	Durable company

Minimum and maximum allocation ranges for fixed income securities and equity securities



	Minimum		Maximum
Equities (long only)	70	%	100	%
Real estate	0	%	15	%
Commodities	0	%	10	%
Fixed income/Cash	0	%	10	%

Actual and estimated future contributions and actual and estimated future benefit payments

Tables 11.12 and 11.13 show the current and estimated future contributions and benefit payments.



Company contributions
Table	11.12
		Pension and Supplemental Executive Retirement Plans		Other Postretirement Benefits
(In thousands)		12/31/2018		12/31/2018
Company Contributions for the Year Ending:
1. Current		$	10,908	$	—
2. Current + 1		10,650		—



Benefits payments - total
Table	11.13
		Pension and Supplemental Executive Retirement Plans		Other Postretirement Benefits
(In thousands)		12/31/2018		12/31/2018
Actual Benefit Payments for the Year Ending:
1. Current		$	33,582	$	652
Expected Benefit Payments for the Year Ending:
2. Current + 1		33,258		1,352
3. Current + 2		28,688		1,650
4. Current + 3		30,574		1,916
5. Current + 4		30,490		2,386
6. Current + 5		30,510		2,613
7. Current + 6 - 10		143,389		14,065

Effect of a 1% change in the health care trend rate assumption

A 1 percentage point change in the health care trend rate assumption would have the following effects on other postretirement benefits:



Health care trend rate assumption
Table	11.14
(In thousands)		1-Percentage Point Increase		1-Percentage Point Decrease
Effect on total service and interest cost components		$	327	$	(282	)
Effect on postretirement benefit obligation		3,221		(2,866		)

Pension Plan

Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]

Fair value of plan assets



Pension plan assets at fair value as of December 31, 2018
Table	11.10a
(In thousands)		Level 1		Level 2		Total
Domestic Mutual Funds		$	13,744	$	—	$	13,744
Corporate Bonds		—		181,363		181,363
U.S. Government Securities		19,904		1,324		21,228
Municipal Bonds		—		43,424		43,424
Foreign Bonds		—		30,113		30,113
ETFs		5,241		—		5,241
Pooled Equity Accounts		—		64,606		64,606
Total Assets at fair value		$	38,889	$	320,830	$	359,719



Pension plan assets at fair value as of December 31, 2017
Table	11.10b
(In thousands)		Level 1		Level 2		Total
Domestic Mutual Funds		$	1,006	$	—	$	1,006
Corporate Bonds		—		202,840		202,840
U.S. Government Securities		17,996		1,400		19,396
Municipal Bonds		—		62,293		62,293
Foreign Bonds		—		32,949		32,949
ETFs		5,734		—		5,734
Pooled Equity Accounts		—		76,924		76,924
Total Assets at fair value		$	24,736	$	376,406	$	401,142

Other Postretirement Benefit Plan

Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]

Fair value of plan assets

Tables 11.11a and 11.11b set forth the other postretirement benefits plan assets at fair value as of December 31, 2018 and 2017. All are Level 1 assets.



Other postretirement benefits plan assets at fair value as of December 31, 2018
Table	11.11a
(In thousands)		Level 1		Total
Domestic Mutual Funds		$	60,405	$	60,405
International Mutual Funds		17,357		17,357
Total Assets at fair value		$	77,762	$	77,762



Other postretirement benefits plan assets at fair value as of December 31, 2017
Table	11.11b
(In thousands)		Level 1		Total
Domestic Mutual Funds		$	64,489	$	64,489
International Mutual Funds		20,814		20,814
Total Assets at fair value		$	85,303	$	85,303

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Net deferred tax assets and liabilities

Net deferred tax assets and liabilities as of December 31, 2018 and 2017 are as follows:



Deferred tax assets and liabilities
Table	12.1
(In thousands)		2018			2017
Total deferred tax assets		$	83,082		$	258,663
Total deferred tax liabilities		(13,898		)	(24,282		)
Net deferred tax asset		$	69,184		$	234,381

Components of the net deferred tax asset (liability)

Table 12.2 includes the components of the net deferred tax asset as of December 31, 2018 and 2017.



Deferred tax components
Table	12.2
(In thousands)		2018			2017
Unearned premium reserves		$	31,808		$	29,196
Benefit plans		(5,047		)	(7,162		)
Federal net operating loss		—			155,839
Loss reserves		3,113			4,994
Unrealized depreciation (appreciation) in investments		9,407			(7,782		)
Mortgage investments		8,307			8,963
Deferred compensation		8,662			7,265
AMT credit carryforward		17,521			37,017
Other, net		(4,587		)	6,051
Net deferred tax asset		$	69,184		$	234,381

Components of the provision for (benefit from) income taxes

Table 12.3 summarizes the components of the provision for (benefit from) income taxes:



Provision for (benefit from) income taxes
Table	12.3
(In thousands)		2018			2017		2016
Current Federal		$	(16,272	)	$	73,348	$	9,470
Deferred Federal		185,598			351,677		160,657
Other		4,727			3,710		2,070
Provision for income taxes		$	174,053		$	428,735	$	172,197

Reconciliation of federal statutory income tax rate

Table 12.6 reconciles the federal statutory income tax rate to our effective tax provision rate.



Effective tax rate reconciliation
Table	12.6
		2018		2017		2016
Federal statutory income tax rate		21.0	%	35.0	%	35.0	%
Additional income tax provision related to the rate decrease included in the Tax Act		—	%	17.0	%	—	%
Additional income tax provision related to IRS litigation		(0.3	)%	3.7	%	0.1	%
Tax exempt municipal bond interest		(0.7	)%	(1.4	)%	(1.9	)%
Other, net		0.6	%	0.4	%	0.3	%
Effective tax rate		20.6	%	54.7	%	33.5	%

Reconciliation of unrecognized tax benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is shown in table 12.7.



Unrecognized tax benefits reconciliation
Table	12.7
(In thousands)		2018			2017			2016
Balance at beginning of year		$	142,821		$	108,245		$	107,120
Additions for tax positions of prior years		—			35,003			1,125
Reductions for tax positions of prior years		(3,070		)	(427		)	—
Settlements		(139,751		)	—			—
Balance at end of year		$	—		$	142,821		$	108,245

Statutory Information (Tables)

12 Months Ended

Dec. 31, 2018

Statutory Capital [Abstract]

Summary of amounts disclosed under statutory accounting practices



Statutory financial information of holding company and insurance subsidiaries
Table	14.1
		As of and for the Years Ended December 31,
(In thousands)		2018		2017		2016
Statutory net income		$	375,484	$	310,776	$	106,326
Statutory policyholders' surplus		1,683,058		1,622,115		1,506,475
Contingency reserve		2,442,996		1,896,701		1,360,088

The surplus contributions made to MGIC, dividends paid by MGIC, and distributions from other insurance subsidiaries to us, are shown in table 14.2 below.



Surplus contributions and dividends of insurance subsidiaries
Table	14.2
		Years Ended December 31,
(In thousands)		2018		2017	2016
Additions to the surplus of MGIC from parent company funds		$	—	—	36,025
Dividends paid by MGIC to the parent company		$	220,000	140,000	64,000
Distributions from other insurance subsidiaries to the parent company		$	—	—	52,001

- Definition

Tabular disclosure of how the entity's reporting under GAAP as of the balance sheet date differs from the results based on prescribed and permitted accounting practices of the state or country of domicile in which a relevant statutory filing is made, or differences in results based on the National Association of Insurance Commissioners (NAIC) prescribed practices, or a combination thereof. Describes the accounting practices used and the related monetary effect on statutory surplus, net income, and risk-based capital. If an insurance enterprise's risk-based capital would have triggered a regulatory event had it not used a permitted practice, that fact is disclosed in the financial statements. Permitted statutory accounting practices include practices not prescribed but allowed by the domiciliary state insurance department regulatory authority.

+ References + Details

Unaudited Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2018

Quarterly Financial Information Disclosure [Abstract]

Unaudited quarterly financial data



Unaudited quarterly financial data - current year:
Table:	18.1a
2018:		Quarter												Full
(In thousands, except per share data)		First			Second			Third			Fourth			Year
Net premiums earned		$	232,107		$	246,964		$	250,426		$	245,665		$	975,162
Investment income, net of expenses		32,121			34,502			36,380			38,328			141,331
Realized (losses) gains		(329		)	(1,897		)	1,114			(241		)	(1,353		)
Other revenue		1,871			2,431			2,525			1,881			8,708
Loss incurred, net		23,850			(13,455		)	(1,518		)	27,685			36,562
Underwriting and other expenses, net		61,895			57,933			60,069			63,239			243,136
Provision for income tax		36,388			50,708			49,994			36,963			174,053
Net income		143,637			186,814			181,900			157,746			670,097
Income per share ^{(a) (b)}:
Basic		0.39			0.51			0.50			0.44			1.83
Diluted		0.38			0.49			0.49			0.43			1.78



Unaudited quarterly financial statements - prior year:
Table:	18.1b
2017:		Quarter												Full
(In thousands, except per share data)		First			Second			Third			Fourth			Year
Net premiums earned		$	229,103		$	231,136		$	237,083		$	237,425		$	934,747
Investment income, net of expenses		29,477			29,716			30,402			31,276			120,871
Realized gains (losses)		(125		)	(52		)	(50		)	458			231
Other revenue		2,425			2,512			2,925			2,343			10,205
Loss incurred, net		27,619			27,339			29,747			(30,996		)	53,709
Underwriting and other expenses, net		59,304			55,292			56,146			57,042			227,784
Loss on debt extinguishment		—			65			—			—			65
Provision for income tax		84,159			61,994			64,440			218,142			428,735
Net income		89,798			118,622			120,027			27,314			355,761
Income per share^{(a) (b)}:
Basic		0.26			0.32			0.32			0.07			0.98
Diluted		0.24			0.31			0.32			0.07			0.95


^(a)	Due to the use of weighted average shares outstanding when calculating earnings per share, the sum of the quarterly per share data may not equal the per share data for the year.


^(b)	In periods where convertible debt instruments are dilutive to earnings per share the “if-converted” method of computing diluted EPS requires an interest expense adjustment, net of tax, to net income available to shareholders. See Note 4 – “Earnings Per Share” for further discussion on our calculation of diluted EPS.

Significant Accounting Policies (Details)	12 Months Ended
Significant Accounting Policies (Details)	Dec. 31, 2018 USD ($) Payment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Home office and equipment [Abstract]
Accumulated depreciation of home office and equipment	$ 38,100,000	$ 33,900,000	$ 30,600,000
Depreciation expense of home office and equipment	$ 6,000,000	5,400,000	4,600,000
Minimum number of payments past due to be in default \| Payment	2
Maximum age for qualified employees for both medical and dental benefits	65 years
Related party transaction amount	$ 0	$ 0	$ 0
Minimum
Home office and equipment [Abstract]
Estimated useful life	3 years
Award vesting period	1 year
Maximum
Home office and equipment [Abstract]
Estimated useful life	45 years
Award vesting period	3 years

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic earnings per share [Abstract]
Net income	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 27,314	$ 120,027	$ 118,622	$ 89,798	$ 670,097	$ 355,761	$ 342,517
Weighted average common shares outstanding - basic (in shares)									365,406	362,380	342,890
Basic earnings per share (in dollars per share)	$ 0.44	$ 0.50	$ 0.51	$ 0.39	$ 0.07	$ 0.32	$ 0.32	$ 0.26	$ 1.83	$ 0.98	$ 1.00
Diluted earnings per share [Abstract]
Net income	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 27,314	$ 120,027	$ 118,622	$ 89,798	$ 670,097	$ 355,761	$ 342,517
Diluted income available to common shareholders									$ 688,361	$ 373,404	$ 370,883
Weighted-average shares - basic (in shares)									365,406	362,380	342,890
Effect of dilutive securities [Abstract]
Weighted-average shares - diluted (in shares)									386,078	394,766	431,992
Diluted income per share (in dollars per share)	$ 0.43	$ 0.49	$ 0.49	$ 0.38	$ 0.07	$ 0.32	$ 0.31	$ 0.24	$ 1.78	$ 0.95	$ 0.86
Federal statutory income tax rate (in hundredths)									21.00%	35.00%	35.00%
2% Convertible Senior Notes due 2020
Diluted earnings per share [Abstract]
Dilutive securities									$ 0	$ 907	$ 6,111
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)									0	8,317	54,450
Stated interest rate (in hundredths)					2.00%					2.00%
5% Convertible Senior Notes due 2017
Diluted earnings per share [Abstract]
Dilutive securities									$ 0	$ 1,709	$ 6,362
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)									0	3,548	13,107
Stated interest rate (in hundredths)					5.00%					5.00%
9% Convertible Junior Subordinated Debentures due 2063
Diluted earnings per share [Abstract]
Dilutive securities									$ 18,264	$ 15,027	$ 15,893
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)									19,028	19,028	20,075
Stated interest rate (in hundredths)	9.00%								9.00%
Unvested Restricted Stock Units
Effect of dilutive securities [Abstract]
Dilutive securities - Share based compensation (in shares)									1,644	1,493	1,470

Investments (Details)	12 Months Ended
Investments (Details)	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($)
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	$ 5,196,784,000	$ 4,946,278,000
Total at end of period	5,151,987,000	4,983,315,000
Assets held by insurance regulatory requirements	13,500,000	13,600,000
Assets held in trust for the benefit of contractual counterparties	26,300,000	7,700,000
Maturities, Amortized Cost [Abstract]
Due in one year or less	484,485,000
Due after one year through five years	1,652,638,000
Due after five years through ten years	1,011,237,000
Due after ten years	1,160,294,000
Total debt securities with single maturity date	4,308,654,000
Total at end of period	5,196,784,000	4,946,278,000
Maturities, Fair Value [Abstract]
Due in one year or less	482,919,000
Due after one year through five years	1,632,494,000
Due after five years through ten years	996,335,000
Due after ten years	1,176,290,000
Total debt securities with single maturity date	4,288,038,000
Total at end of period	5,151,987,000	4,983,315,000
Other than temporary impairments recorded in other comprehensive (loss) income	0	0
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Equity securities, cost	3,993,000
Equity securities, at fair value	$ 3,932,000
Available-for-sale Equity Securities, Amortized Cost Basis [Abstract]
Equity securities, cost		7,223,000
Equity securities, at fair value		7,246,000
Collateral, principal balance of FHLB (as a percent)	102.00%
Collateral, principal balance of FHLB	$ 168,900,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	2,026,193,000	1,667,170,000
12 months or greater	1,554,704,000	752,693,000
Total investment portfolio	3,580,897,000	2,419,863,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(28,520,000)	(9,357,000)
12 months or greater	(49,384,000)	(22,206,000)
Total investment portfolio	$ (77,904,000)	$ (31,563,000)
Number of securities in unrealized loss position \| security	721	586
For securities in an unrealized loss position, percentage of fair value to amortized cost (in hundredths)	98.00%
For securities in an unrealized loss position, percentage backed by the U.S. Government (in hundredths)	8.00%
Total fixed income securities
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	$ 5,196,784,000	$ 4,946,278,000
Gross Unrealized Gains	33,107,000	68,584,000
Gross Unrealized Losses	(77,904,000)	(31,547,000)
Total at end of period	5,151,987,000	4,983,315,000
Maturities, Amortized Cost [Abstract]
Total at end of period	5,196,784,000	4,946,278,000
Maturities, Fair Value [Abstract]
Total at end of period	5,151,987,000	4,983,315,000
Proceeds from sale of fixed income securities available for sale	365,600,000	246,900,000	$ 728,000,000
Gross realized gains	700,000	1,600,000	11,900,000
Gross realized losses	3,800,000	1,400,000	3,000,000
Recognized other than temporary impairments	1,800,000	0	$ 0
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	167,655,000	179,850,000
Gross Unrealized Gains	597,000	274,000
Gross Unrealized Losses	(1,076,000)	(1,278,000)
Total at end of period	167,176,000	178,846,000
Maturities, Amortized Cost [Abstract]
Total at end of period	167,655,000	179,850,000
Maturities, Fair Value [Abstract]
Total at end of period	167,176,000	178,846,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	23,710,000	144,042,000
12 months or greater	69,146,000	31,196,000
Total investment portfolio	92,856,000	175,238,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(15,000)	(796,000)
12 months or greater	(1,061,000)	(482,000)
Total investment portfolio	(1,076,000)	(1,278,000)
Obligations of U.S. states and political subdivisions
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	1,701,826,000	2,105,063,000
Gross Unrealized Gains	29,259,000	56,210,000
Gross Unrealized Losses	(10,985,000)	(8,749,000)
Total at end of period	1,720,100,000	2,152,524,000
Maturities, Amortized Cost [Abstract]
Total at end of period	1,701,826,000	2,105,063,000
Maturities, Fair Value [Abstract]
Total at end of period	1,720,100,000	2,152,524,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	316,655,000	505,311,000
12 months or greater	358,086,000	211,684,000
Total investment portfolio	674,741,000	716,995,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(3,875,000)	(3,624,000)
12 months or greater	(7,110,000)	(5,125,000)
Total investment portfolio	(10,985,000)	(8,749,000)
Corporate debt securities
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	2,439,173,000	2,065,475,000
Gross Unrealized Gains	2,103,000	10,532,000
Gross Unrealized Losses	(40,514,000)	(9,169,000)
Total at end of period	2,400,762,000	2,066,838,000
Maturities, Amortized Cost [Abstract]
Total at end of period	2,439,173,000	2,065,475,000
Maturities, Fair Value [Abstract]
Total at end of period	2,400,762,000	2,066,838,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	1,272,279,000	932,350,000
12 months or greater	785,627,000	200,716,000
Total investment portfolio	2,057,906,000	1,133,066,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(18,130,000)	(4,288,000)
12 months or greater	(22,384,000)	(4,881,000)
Total investment portfolio	(40,514,000)	(9,169,000)
ABS
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	111,953,000	4,925,000
Gross Unrealized Gains	226,000	0
Gross Unrealized Losses	(146,000)	(2,000)
Total at end of period	112,033,000	4,923,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	111,953,000
Total at end of period	111,953,000	4,925,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	112,033,000
Total at end of period	112,033,000	4,923,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	51,324,000	4,923,000
12 months or greater	0	0
Total investment portfolio	51,324,000	4,923,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(146,000)	(2,000)
12 months or greater	0	0
Total investment portfolio	(146,000)	(2,000)
RMBS
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	189,238,000	189,153,000
Gross Unrealized Gains	32,000	60,000
Gross Unrealized Losses	(10,309,000)	(7,364,000)
Total at end of period	178,961,000	181,849,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	189,238,000
Total at end of period	189,238,000	189,153,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	178,961,000
Total at end of period	178,961,000	181,849,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	24,000	14,979,000
12 months or greater	178,573,000	166,329,000
Total investment portfolio	178,597,000	181,308,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	0	(280,000)
12 months or greater	(10,309,000)	(7,084,000)
Total investment portfolio	(10,309,000)	(7,364,000)
CMBS
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	276,352,000	301,014,000
Gross Unrealized Gains	888,000	1,204,000
Gross Unrealized Losses	(9,580,000)	(4,906,000)
Total at end of period	267,660,000	297,312,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	276,352,000
Total at end of period	276,352,000	301,014,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	267,660,000
Total at end of period	267,660,000	297,312,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	65,704,000	51,096,000
12 months or greater	163,272,000	138,769,000
Total investment portfolio	228,976,000	189,865,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(1,060,000)	(358,000)
12 months or greater	(8,520,000)	(4,548,000)
Total investment portfolio	(9,580,000)	(4,906,000)
CLOs
Available-for-sale Debt Securities, Amortized Cost Basis [Abstract]
Total at end of period	310,587,000	100,798,000
Gross Unrealized Gains	2,000	304,000
Gross Unrealized Losses	(5,294,000)	(79,000)
Total at end of period	305,295,000	101,023,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	310,587,000
Total at end of period	310,587,000	100,798,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	305,295,000
Total at end of period	305,295,000	101,023,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months	296,497,000	14,243,000
12 months or greater	0	3,568,000
Total investment portfolio	296,497,000	17,811,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	(5,294,000)	(7,000)
12 months or greater	0	(72,000)
Total investment portfolio	(5,294,000)	(79,000)
Equity securities
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Equity securities, cost	3,993,000
Gross gains	11,000
Gross losses	(72,000)
Equity securities, at fair value	3,932,000
Proceeds from sale of equity securities	4,900,000
Gross realized gains on equity securities	3,700,000
Recognized net losses on equity securities still held	$ 84,000
Available-for-sale Equity Securities, Amortized Cost Basis [Abstract]
Equity securities, cost		7,223,000
Gross gains		39,000
Gross losses		(16,000)
Equity securities, at fair value		7,246,000
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months		226,000
12 months or greater		431,000
Total investment portfolio		657,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months		(2,000)
12 months or greater		(14,000)
Total investment portfolio		$ (16,000)

Investments, Investment Income By Category (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									$ 145,006	$ 124,378	$ 113,882
Investment expenses									(3,675)	(3,507)	(3,216)
Net investment income	$ 38,328	$ 36,380	$ 34,502	$ 32,121	$ 31,276	$ 30,402	$ 29,716	$ 29,477	141,331	120,871	110,666
Fixed income securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									140,539	122,105	112,513
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									228	206	182
Cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									3,423	1,447	754
Other
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									$ 816	$ 620	$ 433

Investments, Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gain (Loss) on Investments [Line Items]
Change in unrealized gains (losses)	$ (81,834)	$ 69,052	$ (5,425)
Available-for-Sale Securities \| Fixed income
Gain (Loss) on Investments [Line Items]
Change in unrealized gains (losses)	(81,834)	69,026	(5,403)
Available-for-Sale Securities \| Equity Securities
Gain (Loss) on Investments [Line Items]
Change in unrealized gains (losses)	0	39	(36)
Available-for-Sale Securities \| Other
Gain (Loss) on Investments [Line Items]
Change in unrealized gains (losses)	$ 0	$ (13)	$ 14

Fair Value Measurements - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 4,539	$ 4,959	$ 4,083
Transfers out of Level 3	(3,100)
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as net realized investment gains	3,663		3,579
Included in earnings and reported as losses incurred, net	0	0	0
Purchases	0	0	4,258
Sales	(5,089)	(420)	(6,961)
Balance at end of period	13	4,539	4,959
Total fixed income securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	271	691	1,228
Transfers out of Level 3	0
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as net realized investment gains	0		0
Included in earnings and reported as losses incurred, net	0	0	0
Purchases	0	0	0
Sales	(258)	(420)	(537)
Balance at end of period	13	271	691
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	4,268	4,268	2,855
Transfers out of Level 3	(3,100)
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as net realized investment gains	3,663		3,579
Included in earnings and reported as losses incurred, net	0	0	0
Purchases	0	0	4,258
Sales	(4,831)	0	(6,424)
Balance at end of period	0	4,268	4,268
Real Estate Acquired
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	12,713	11,748	12,149
Transfers out of Level 3	0
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as net realized investment gains	0		0
Included in earnings and reported as losses incurred, net	(1,995)	(1,315)	(1,142)
Purchases	33,912	34,749	36,859
Sales	(30,095)	(32,469)	(36,118)
Balance at end of period	$ 14,535	$ 12,713	$ 11,748

Fair Value Measurements - Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Senior Notes \| 5.75% Senior Notes due 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate (in hundredths)	5.75%
9% Convertible Junior Subordinated Debentures due 2063
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate (in hundredths)	9.00%
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
FHLB Advance	$ 155,000	$ 155,000
5.75% Notes	419,713	418,560
9% Debentures	256,872	256,872
Total financial liabilities	831,585	830,432
Fair Value \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
FHLB Advance	150,551	152,124
5.75% Notes	425,791	465,473
9% Debentures	338,069	353,507
Total financial liabilities	$ 914,411	$ 971,104

Debt Summary of Obligations (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 831,600,000	$ 830,400,000
Federal Home Loan Bank Advances (FHLB)
Debt Instrument [Line Items]
Long-term debt, carrying value	155,000,000	155,000,000
Senior Notes \| 5.75% Senior Notes due 2023
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 419,700,000	418,500,000
Stated interest rate (in hundredths)	5.75%
Debt instrument, face amount	$ 425,000,000
Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 256,900,000	$ 256,900,000
Stated interest rate (in hundredths)	9.00%

Debt (Details)	12 Months Ended
Debt (Details)	Dec. 31, 2018 USD ($) Period $ / shares shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
FHLBC advances	$ 155,000,000
FHLBC fixed interest rate	1.91%
Collateral, principal balance of FHLB (as a percent)	102.00%
Interest paid	$ 51,300,000	$ 57,800,000	$ 49,500,000
Senior Notes \| 5.75% Senior Notes due 2023
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	5.75%
Redemption price, percentage (in hundredths)	100.00%
Ownership percentage threshold for declaration of due and payable	25.00%
Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	9.00%
Redemption price, percentage (in hundredths)	100.00%
Conversion rate (in shares per $1,000 note) \| shares	74.0741
Principal amount of notes used in determining conversion rate	$ 1,000
Initial conversion price (in dollars per share) \| $ / shares	$ 13.50
Period preceding election to convert	5 days
Convertible debt, number of equity instruments reserved for conversion \| shares	19,000,000
Closing sale price of our common stock for consideration of redemption (in dollars per share) \| $ / shares	$ 17.55
Minimum number of trading days	20 days
Maximum number of trading days	30 days
Minimum number of consecutive interest periods for which interest payments may be deferred \| Period	1
Maximum period for which interest payments may be deferred without giving rise to an event of default	10 years
Period in which reasonable commercial efforts must begin, maximum	1 day
Anniversary payment release of the start of the interest deferral to the Alternative Payment Mechanism in lieu of the final maturity of the debentures	10 years
Net proceeds cap (in hundredths)	2.00%
Maximum number of shares of common stock issuable under the Alternative Payment Mechanism (in shares) \| shares	10,000,000
Maximum percentage of aggregate principal amount of the debentures (in hundredths)	25.00%
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 175,000,000

Loss Reserves - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
Loss Reserves - Narrative (Details) $ in Thousands	Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 loan	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Premium refund liability, expected claim payments	$ 61,000		$ 40,000	$ 61,000
Other items removed from inventory \| loan			1,578	1,337	1,273
Losses for unpaid claims and adjustment expense			$ 327,743	$ 493,300	$ 689,258
Default notices for loans in IADAs \| loan	9,294	1,968
Default inventory in FEMA individual assistance disaster areas \| loan	12,446	7,162		12,446	7,162
Percent of inventory in default for more than 36 consecutive months	45.00%	47.00%	38.00%	45.00%	47.00%
Pool insurance notice inventory (in number of loans) \| loan	1,309	1,883	859	1,309	1,883
Decrease in estimated claim rate on primary delinquencies
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Percentage of prior year default inventory resolved (in hundredths)			73.00%	67.00%	63.00%
Settlements for commutations of coverage, pools of nonperforming loans
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Losses for unpaid claims and adjustment expense			$ 50,000	$ 54,000
Settlements for commutations of coverage, pools of nonperforming loans, and claims paying practices
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Losses for unpaid claims and adjustment expense					$ 53,000
Payments for settlements \| Freddie Mac
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Losses for unpaid claims and adjustment expense					$ 42,000

Loss Reserves - Reconciliation of Changes in Loss Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Reserve [Roll Forward]
Reserve at beginning of year	$ 985,635	$ 1,438,813	$ 1,893,402
Less reinsurance recoverable	33,328	48,474	50,493	$ 44,487
Net reserve at beginning of year	640,691	937,161	1,388,320	$ 1,848,915
Losses incurred: [Abstract]
Current year	203,928	284,913	387,815
Prior years	(167,366)	(231,204)	(147,658)
Total losses incurred	36,562	53,709	240,157
Losses paid [Abstract]
Current year	7,298	11,267	14,823
Prior years	327,743	493,300	689,258
Reinsurance terminations	(2,009)	301	(3,329)
Total losses paid	333,032	504,868	700,752
Reserve at end of year	$ 674,019	$ 985,635	$ 1,438,813

Loss Reserves - Prior Year Loss Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	$ (167,366)	$ (231,204)	$ (147,658)
Decrease in estimated claim rate on primary delinquencies
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	(213,000)	(248,000)	(148,000)
Increase in estimated severity on primary delinquencies
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	29,000	9,000	9,000
Change in estimates related to pool reserves, LAE reserves, reinsurance and other
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	$ 17,000	$ 8,000	$ (9,000)

Loss Reserves - Default Inventory Reconciliation (Details) - loan	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Primary Default Inventory [Roll Forward]
Beginning delinquent inventory	46,556	50,282	62,633
New Notices	54,448	68,268	67,434
Cures	(60,511)	(61,094)	(65,516)
Paid claims	(5,750)	(9,206)	(12,367)
Rescissions and denials	(267)	(357)	(629)
Other items removed from inventory	(1,578)	(1,337)	(1,273)
Ending delinquent inventory	32,898	46,556	50,282

Loss Reserves - Aging of Primary Default Inventory and Number of Delinquent Payments (Details) - loan	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Aging of the Primary Default Inventory [Abstract]
3 months or less	9,829	17,119	12,194
4 - 11 months	9,655	12,050	13,450
12 months or more	13,414	17,387	24,638
Total primary default inventory	32,898	46,556	50,282	62,633
3 months or less (in hundredths)	30.00%	37.00%	24.00%
4 - 11 months (in hundredths)	29.00%	26.00%	27.00%
12 months or more (in hundredths)	41.00%	37.00%	49.00%
Total primary default inventory (in hundredths)	100.00%	100.00%	100.00%
Primary claims received inventory included in ending default inventory	809	954	1,385

Reinsurance - Summary of Reinsurance Agreements (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premiums Earned, Net [Abstract]
Premiums earned, direct									$ 1,084,748	$ 1,059,973	$ 1,058,545
Premiums earned, assumed									1,805	509	662
Premiums earned, ceded									(111,391)	(125,735)	(133,981)
Net premiums earned	$ 245,665	$ 250,426	$ 246,964	$ 232,107	$ 237,425	$ 237,083	$ 231,136	$ 229,103	975,162	934,747	925,226
Policyholder Benefits and Claims Incurred, Net [Abstract]
Losses incurred, direct									43,060	74,727	273,207
Losses incurred, assumed									331	183	1,138
Losses incurred, ceded									(6,829)	(21,201)	(34,188)
Net losses incurred	$ 27,685	$ (1,518)	$ (13,455)	$ 23,850	$ (30,996)	$ 29,747	$ 27,339	$ 27,619	36,562	53,709	240,157
Ceded losses incurred									6,829	21,201	34,188
Quota Share Reinsurance Agreements, Excluding Captives
Policyholder Benefits and Claims Incurred, Net [Abstract]
Losses incurred, ceded									(6,543)	(22,336)	(30,201)
Ceded premiums written and earned, net of profit commission									108,337	120,974	125,460
Ceded losses incurred									6,543	22,336	30,201
Ceding commissions									51,201	49,321	47,629
Profit commission									$ 147,667	$ 125,629	$ 112,685

Reinsurance - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
Reinsurance - Narrative (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves		$ 33,328,000	$ 48,474,000	$ 50,493,000	$ 44,487,000
Aggregate excess of loss reinsurance coverage		318,600,000
Ceded premiums earned		$ 111,391,000	125,735,000	$ 133,981,000
Amortization period excess of loss reinsurance coverage		10 years
Quota Share Reinsurance Agreement, 2018
Effects of Reinsurance [Line Items]
Contingent termination fee		$ 0
Threshold for private mortgage insurer eligibility requirements for termination election		90.00%
Quota share, percentage		30.00%
Ceding commission, percentage		20.00%
Loss ratio		62.00%
Quota Share Reinsurance Agreement, 2017
Effects of Reinsurance [Line Items]
Contingent termination fee		$ 0
Threshold for private mortgage insurer eligibility requirements for termination election		90.00%
Quota share, percentage		30.00%
Ceding commission, percentage		20.00%
Loss ratio		60.00%
Quota Share Reinsurance Agreement, 2015
Effects of Reinsurance [Line Items]
Contingent termination fee		$ 0
Threshold for private mortgage insurer eligibility requirements for termination election		90.00%
Early termination written notice period		90 days
Quota share, percentage		30.00%
Ceding commission, percentage		20.00%
Loss ratio		60.00%
Quota Share Reinsurance Agreements, Excluding Captives
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves		$ 33,200,000	$ 39,300,000
Quota Share Reinsurance Agreement, 2019 \| Forecast
Effects of Reinsurance [Line Items]
Contingent termination fee	$ 0
Threshold for private mortgage insurer eligibility requirements for termination election	90.00%
Quota share, percentage	30.00%
Ceding commission, percentage	20.00%
Loss ratio	62.00%
Cede rate, option 1	25.00%
Cede rate, option 2	20.00%
Excess of Loss Reinsurance Agreement, Home Re
Effects of Reinsurance [Line Items]
Ceded premiums earned		$ 2,800,000
Mortgage Guaranty Insurance Corporation
Effects of Reinsurance [Line Items]
Loss ratio		4.00%
First layer of aggregate losses retained		$ 168,700,000
Home Re 2018-1
Effects of Reinsurance [Line Items]
Total VIE Assets		$ 318,636,000
Percent of total trust assets invested in cash or direct U.S. federal government obligations		99.50%
Home Re 2018-1 \| Mortgage Insurance Linked Notes
Effects of Reinsurance [Line Items]
Debt instrument, face amount		$ 318,600,000
Term of mortgage insurance-linked notes		10 years

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of Other Comprehensive Income (Loss) [Abstract]
Net unrealized investment (losses) gains arising during the year									$ (81,834)	$ 69,052	$ (5,425)
Income tax benefit (expense)									17,188	(21,505)	1,776
Net of taxes									(64,646)	47,547	(3,649)
Net changes in benefit plan assets and obligations									(19,958)	(8,983)	(14,799)
Income tax benefit									4,191	3,144	5,179
Net of taxes									(15,767)	(5,839)	(9,620)
Net changes in unrealized foreign currency translation adjustment									0	45	(1,463)
Income tax (expense) benefit									0	(14)	512
Net of taxes									0	31	(951)
Total other comprehensive (loss) income									(101,792)	60,114	(21,687)
Total income tax benefit (expense), net									21,379	(18,375)	7,467
Other comprehensive (loss) income, net of tax									(80,413)	41,739	(14,220)
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications									844,150	784,496	514,714
Total income tax benefit (expense), net	$ (36,963)	$ (49,994)	$ (50,708)	$ (36,388)	$ (218,142)	$ (64,440)	$ (61,994)	$ (84,159)	(174,053)	(428,735)	(172,197)
Net income	157,746	$ 181,900	$ 186,814	143,637	27,314	$ 120,027	$ 118,622	89,798	670,097	355,761	342,517
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				3,154,526				2,548,842	3,154,526	2,548,842
Balance, end of year	3,581,891				3,154,526				3,581,891	3,154,526	2,548,842
Accumulated other comprehensive loss
Components of Other Comprehensive Income (Loss) [Abstract]
Other comprehensive (loss) income, net of tax									(80,413)	41,739	(14,220)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				(43,783)				(75,100)	(43,783)	(75,100)	(60,880)
Cumulative effect of accounting standard update					(18)					(18)
Other comprehensive income (loss) before reclassifications									(87,736)	40,651	(8,147)
Less: Amounts reclassified from AOCL									(7,323)	(1,088)	6,073
Less: Amounts reclassified for lower enacted corporate tax rate					10,400					10,422
Balance, end of year	(124,214)				(43,783)				(124,214)	(43,783)	(75,100)
Net unrealized gains and losses on available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				29,275				(20,797)	29,275	(20,797)	(17,148)
Cumulative effect of accounting standard update					(18)					(18)
Other comprehensive income (loss) before reclassifications									(70,206)	45,870	508
Less: Amounts reclassified from AOCL									(5,560)	(1,677)	4,157
Less: Amounts reclassified for lower enacted corporate tax rate										(2,525)
Balance, end of year	(35,389)				29,275				(35,389)	29,275	(20,797)
Net benefit plan assets and obligations recognized in shareholders' equity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				(73,058)				(54,272)	(73,058)	(54,272)	(44,652)
Other comprehensive income (loss) before reclassifications									(17,530)	(5,250)	(8,658)
Less: Amounts reclassified from AOCL									(1,763)	589	962
Less: Amounts reclassified for lower enacted corporate tax rate										12,947
Balance, end of year	(88,825)				(73,058)				(88,825)	(73,058)	(54,272)
Net unrealized foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				$ 0				$ (31)	0	(31)	920
Other comprehensive income (loss) before reclassifications									0	31	3
Less: Amounts reclassified from AOCL									0	0	954
Less: Amounts reclassified for lower enacted corporate tax rate										0
Balance, end of year	$ 0				$ 0				0	0	(31)
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications									(9,269)	(1,674)	9,154
Total income tax benefit (expense), net									1,946	586	(3,081)
Net income									(7,323)	(1,088)	6,073
Reclassification from Accumulated Other Comprehensive Income \| Net unrealized gains and losses on available-for-sale securities
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications									(7,037)	(2,580)	6,207
Total income tax benefit (expense), net									1,477	903	(2,050)
Net income									(5,560)	(1,677)	4,157
Reclassification from Accumulated Other Comprehensive Income \| Net benefit plan assets and obligations recognized in shareholders' equity
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications									(2,232)	906	1,480
Total income tax benefit (expense), net									469	(317)	(518)
Net income									(1,763)	589	962
Reclassification from Accumulated Other Comprehensive Income \| Net unrealized foreign currency translation
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications									0	0	1,467
Total income tax benefit (expense), net									0	0	(513)
Net income									$ 0	$ 0	$ 954

Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Company Service Cost	$ 10,530	$ 9,556	$ 9,130
Interest Cost	15,095	15,475	15,906
Expected Return on Assets	(22,250)	(20,099)	(19,508)
Other Adjustments	0	0	0
Subtotal	3,375	4,932	5,528
Amortization of Net Transition Obligation/(Asset)	0	0	0
Amortization of Net Prior Service Cost/(Credit)	(351)	(426)	(687)
Amortization of Net Losses/(Gains)	6,937	6,169	5,856
Total Amortization	6,586	5,743	5,169
Net Periodic Benefit Cost	9,961	10,675	10,697
Cost of settlements	0	0	1,277
Total Expense for Year	9,961	10,675	11,974
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Company Service Cost	1,160	813	751
Interest Cost	834	706	704
Expected Return on Assets	(6,359)	(5,248)	(4,886)
Other Adjustments	0	0	0
Subtotal	(4,365)	(3,729)	(3,431)
Amortization of Net Transition Obligation/(Asset)	0	0	0
Amortization of Net Prior Service Cost/(Credit)	(4,104)	(6,649)	(6,649)
Amortization of Net Losses/(Gains)	(250)	0	0
Total Amortization	(4,354)	(6,649)	(6,649)
Net Periodic Benefit Cost	(8,719)	(10,378)	(10,080)
Cost of settlements	0	0	0
Total Expense for Year	$ (8,719)	$ (10,378)	$ (10,080)

Benefit Plans - Development of Funded Status (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation	$ 375,562	$ 411,996
Projected Benefit Obligation	(376,153)	(417,770)	$ (369,808)
Plan Assets at Fair Value	359,719	401,142	360,900
Funded Status - Overfunded/(Underfunded)	(16,434)	(16,628)
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation	28,085	24,716
Projected Benefit Obligation	(28,085)	(24,716)	(17,378)
Plan Assets at Fair Value	77,762	85,303	$ 70,408
Funded Status - Overfunded/(Underfunded)	$ 49,677	$ 60,587

Benefit Plans - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain)/Loss	$ 110,321	$ 109,904
Net Prior Service Cost/(Credit)	(1,513)	(1,850)
Net Transition Obligation/(Asset)	0	0
Total at Year End	108,808	108,054	$ 101,575
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain)/Loss	939	(10,234)
Net Prior Service Cost/(Credit)	2,690	(5,342)
Net Transition Obligation/(Asset)	0	0
Total at Year End	$ 3,629	$ (15,576)	$ (18,079)

Benefit Plans - Change in Project Benefit/Accumulated Benefit Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	$ 417,770	$ 369,808
Company Service Cost	10,530	9,556	$ 9,130
Interest Cost	15,095	15,475	15,906
Plan Participants' Contributions	0	0
Net Actuarial (Gain)/Loss due to Assumption Changes	(36,132)	38,496
Net Actuarial (Gain)/Loss due to Plan Experience	2,487	2,338
Benefit Payments from Fund	(32,674)	(17,578)
Benefit Payments Directly by Company	(908)	(335)
Plan Amendments	(15)	10
Other Adjustment	0	0
Benefit Obligation at End of Year	376,153	417,770	369,808
Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	24,716	17,378
Company Service Cost	1,160	813	751
Interest Cost	834	706	704
Plan Participants' Contributions	475	395
Net Actuarial (Gain)/Loss due to Assumption Changes	(1,209)	5,981
Net Actuarial (Gain)/Loss due to Plan Experience	(692)	924
Benefit Payments from Fund	(1,077)	(1,404)
Benefit Payments Directly by Company	0	0
Plan Amendments	3,928	0
Other Adjustment	(50)	(77)
Benefit Obligation at End of Year	$ 28,085	$ 24,716	$ 17,378

Benefit Plans - Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	$ 401,142	$ 360,900
Company Contributions	10,908	9,435
Plan Participants' Contributions	0	0
Benefit Payments from Fund	(32,674)	(17,578)
Benefit Payments paid directly by Company	(908)	(335)
Actual Return on Assets	(19,583)	48,720
Other Adjustment	834	0
Fair Value of Plan Assets at End of Year	359,719	401,142
Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	85,303	70,408
Company Contributions	0	0
Plan Participants' Contributions	475	395
Benefit Payments from Fund	(1,077)	(1,404)
Benefit Payments paid directly by Company	0	0
Actual Return on Assets	(6,464)	16,299
Other Adjustment	(475)	(395)
Fair Value of Plan Assets at End of Year	$ 77,762	$ 85,303

Benefit Plans - Change in Accumulated Other Comprehensive Income (AOCI) and Expected Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI in Prior Year	$ 108,054	$ 101,575
Recognized during year - Prior Service (Cost)/Credit	351	426
Recognized during year - Net Actuarial (Losses)/Gains	(6,937)	(6,169)
Occurring during year - Prior Service Cost	(15)	10
Occurring during year - Net Actuarial Losses/(Gains)	7,355	12,212
AOCI in Current Year	108,808	108,054
Amortization of Net Transition Obligation/(Asset)	0
Amortization of Prior Service Cost/(Credit)	(280)
Amortization of Net Losses/(Gains)	8,271
Other Postretirement Benefit Plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI in Prior Year	(15,576)	(18,079)
Recognized during year - Prior Service (Cost)/Credit	4,104	6,649
Recognized during year - Net Actuarial (Losses)/Gains	250	0
Occurring during year - Prior Service Cost	3,928	0
Occurring during year - Net Actuarial Losses/(Gains)	10,923	(4,146)
AOCI in Current Year	3,629	$ (15,576)
Amortization of Net Transition Obligation/(Asset)	0
Amortization of Prior Service Cost/(Credit)	(34)
Amortization of Net Losses/(Gains)	$ 0

Benefit Plans - Actuarial Assumptions and Year-End Asset Allocations (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Discount Rate (in hundredths)	4.40%	3.75%
Rate of Compensation Increase (in hundredths)	3.00%	3.00%
Discount Rate (in hundredths)	3.75%	4.30%
Expected Long-term Return on Plan Assets (in hundredths)	5.75%	5.75%
Rate of Compensation Increase (in hundredths)	3.00%	3.00%
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Discount Rate (in hundredths)	4.25%	3.55%
Discount Rate (in hundredths)	3.55%	3.95%
Expected Long-term Return on Plan Assets (in hundredths)	7.50%	7.50%
Health Care Cost Trend Rate Assumed for Next Year (in hundredths)	6.25%	6.50%
Rate to Which the Cost Trend Rate is Assumed to Decline (Ultimate Trend Rate) (in hundredths)	5.00%	5.00%
Year That the Rate Reaches the Ultimate Trend Rate	2024	2024
Weighted-average asset allocations of plans (in hundredths)	100.00%	100.00%
Other Postretirement Benefit Plan \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocations of plans (in hundredths)	100.00%	100.00%
Other Postretirement Benefit Plan \| Total fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocations of plans (in hundredths)	0.00%	0.00%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocations of plans (in hundredths)	100.00%	100.00%
Pension Plan \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocations of plans (in hundredths)	23.00%	21.00%
Pension Plan \| Total fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocations of plans (in hundredths)	77.00%	79.00%

Benefit Plans - Additional Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Company Contributions	$ 0	$ 0
Current plus 1	0
Actual Benefit Payments for the Year Ending: Current	652
Expected Benefit Payments for the Year Ending: Current plus 1	1,352
Expected Benefit Payments for the Year Ending: Current plus 2	1,650
Expected Benefit Payments for the Year Ending: Current plus 3	1,916
Expected Benefit Payments for the Year Ending: Current plus 4	2,386
Expected Benefit Payments for the Year Ending: Current plus 5	2,613
Expected Benefit Payments for the Year Ending: Current plus 6 - 10	14,065
Effect of 1-percentage point increase on total service and interest cost component	327
Effect of 1-percentage point decrease on total service and interest cost components	(282)
Effect of 1-percentage point increase on postretirement benefit obligation	3,221
Effect of 1-percentage point decrease on postretirement benefit obligation	$ (2,866)
Other Postretirement Benefit Plan \| Equity securities \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	70.00%
Other Postretirement Benefit Plan \| Equity securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	100.00%
Other Postretirement Benefit Plan \| Real Estate \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	0.00%
Other Postretirement Benefit Plan \| Real Estate \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	15.00%
Other Postretirement Benefit Plan \| Commodities \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	0.00%
Other Postretirement Benefit Plan \| Commodities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	10.00%
Other Postretirement Benefit Plan \| Fixed Income/Cash \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	0.00%
Other Postretirement Benefit Plan \| Fixed Income/Cash \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	10.00%
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Company Contributions	$ 10,908	$ 9,435
Current plus 1	10,650
Actual Benefit Payments for the Year Ending: Current	33,582
Expected Benefit Payments for the Year Ending: Current plus 1	33,258
Expected Benefit Payments for the Year Ending: Current plus 2	28,688
Expected Benefit Payments for the Year Ending: Current plus 3	30,574
Expected Benefit Payments for the Year Ending: Current plus 4	30,490
Expected Benefit Payments for the Year Ending: Current plus 5	30,510
Expected Benefit Payments for the Year Ending: Current plus 6 - 10	$ 143,389

Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
Benefit Plans - Narrative (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Minimum percentages of gain loss consider for amortization (in hundredths)	10.00%
Minimum value of outstanding noncallable bonds used in hypothetical cash flow bond matching exercise	$ 50,000,000
Future earnings period used in determining the expected average rate of earnings	20 years
Minimum percentage return should exceed growth in consumer price index annually (in hundredths)	5.75%
Maximum investment in international mutual funds (in hundredths)	30.00%
Percent of international mutual funds equity allocation in emerging markets (in hundredths)	3.00%
Percent of international mutual funds equity allocation in companies primarily based in Europe and the Pacific Basin (in hundredths)	19.00%
Discretionary profit sharing contribution as a percentage of participant's eligible compensation (in hundredths)	5.00%
Matching contribution rate on employees' before-tax contributions, first contribution level (in hundredths)	80.00%
Employee contributions subject to employer match, first contribution level	$ 1,000
Matching contribution rate on employees' before-tax contributions, second contribution level (in hundredths)	40.00%
Employee contributions subject to employer match, second contribution level	$ 2,000
Matching contribution rate on employees' before-tax contributions, hired after 01/01/2014 (in hundredths)	100.00%
Employee contributions subject to employer match for employees hired after 01/01/2014 (in hundredths)	4.00%
Profit sharing and 401(k) savings plan expenses	$ 6,000,000	$ 6,000,000	$ 5,900,000
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Lump sum pension plan benefit payments	$ 20,900,000	$ 6,300,000
Pension Plan \| Equity securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	40.00%
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Health Care Cost Trend Rate Assumed for Next Year (in hundredths)	6.25%	6.50%
Rate to Which the Cost Trend Rate is Assumed to Decline (Ultimate Trend Rate) (in hundredths)	5.00%	5.00%
Other Postretirement Benefit Plan \| Equity securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	100.00%

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net deferred tax assets and liabilities [Abstract]
Total deferred tax assets	$ 83,082				$ 258,663				$ 83,082	$ 258,663
Total deferred tax liabilities	(13,898)				(24,282)				(13,898)	(24,282)
Net deferred tax asset	69,184				234,381				69,184	234,381
Components of net deferred tax asset [Abstract]
Unearned premium reserves	31,808				29,196				31,808	29,196
Benefit plans	(5,047)				(7,162)				(5,047)	(7,162)
Federal net operating loss	0				155,839				0	155,839
Loss reserves	3,113				4,994				3,113	4,994
Unrealized depreciation (appreciation) in investments	9,407				(7,782)				9,407	(7,782)
Mortgage investments	8,307				8,963				8,307	8,963
Deferred compensation	8,662				7,265				8,662	7,265
AMT credit carryforward	17,521				37,017				17,521	37,017
Other, net	(4,587)				6,051				(4,587)	6,051
Components of provisions for (benefit from) income taxes [Abstract]
Current Federal									(16,272)	73,348	$ 9,470
Deferred Federal									185,598	351,677	160,657
Other									4,727	3,710	2,070
Provision for income taxes	36,963	$ 49,994	$ 50,708	$ 36,388	218,142	$ 64,440	$ 61,994	$ 84,159	174,053	428,735	172,197
Income tax expense due to remeasurement of net deferred tax assets									133,000
Income taxes paid									$ 12,200	$ 22,000	$ 4,500
Reconciliation of effective income tax rate [Abstract]
Federal statutory income tax rate (in hundredths)									21.00%	35.00%	35.00%
Additional income tax provision related to the rate decrease included in the Tax Act									0.00%	17.00%	0.00%
Additional income tax provision related to IRS litigation (in hundredths)									(0.30%)	3.70%	0.10%
Tax exempt municipal bond interest (in hundredths)									(0.70%)	(1.40%)	(1.90%)
Other, net (in hundredths)									0.60%	0.40%	0.30%
Effective income tax provision rate (in hundredths)									20.60%	54.70%	33.50%
Unrecognized tax benefits [Roll Forward]
Balance at beginning of year				$ 142,821				$ 108,245	$ 142,821	$ 108,245	$ 107,120
Additions for tax positions of prior years									0	35,003	1,125
Reductions for tax positions of prior years									(3,070)	(427)	0
Settlements									(139,751)	0	0
Balance at end of year	$ 0				142,821				0	142,821	$ 108,245
Interest expense recognized during period									(3,100)
Unrecognized tax benefits, accrued interest					$ 52,000					$ 52,000
IRS
Reconciliation of effective income tax rate [Abstract]
Tax and interest payments for IRS settlement									14,800
State tax authorities
Reconciliation of effective income tax rate [Abstract]
Tax and interest payments for IRS settlement									$ 36,800

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	1 Months Ended	3 Months Ended				12 Months Ended
	Apr. 30, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 26, 2018
Debt Instrument [Line Items]
Stock repurchase program, authorized amount									$ 200,000
Shares repurchased during period (in shares)						16.0
Shares repurchased, weighted average price per share						$ 10.95		$ 8.03
Remaining authorized repurchase amount						$ 25,000
Repayments of convertible debt						0	$ 145,620	$ 363,778
Loss on debt extinguishment		$ 0	$ 0	$ (65)	$ 0	$ 0	$ (65)	(90,531)
Shares repurchased, value								147,100
2% Convertible Senior Notes due 2020
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		2.00%					2.00%
Principal amount of notes converted into shares	$ 202,500
Shares issued during period upon conversion of convertible debt (in shares)	29.1
Treasury stock reissued during period upon conversion of notes (in shares)	18.7
Stock issued during period upon conversion of notes, new issues (in shares)	10.4
Extinguishment of debt, amount								292,400
Repayments of convertible debt								230,700
Loss on debt extinguishment								74,300
Repayments of long-term debt								$ 362,100
Repayments of debt (in shares)								18.3
5% Convertible Senior Notes due 2017
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		5.00%					5.00%
Extinguishment of debt, amount								$ 188,500
Repayments of convertible debt								195,500
Loss on debt extinguishment								7,900
Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
Debt Instrument [Line Items]
Stated interest rate (in hundredths)						9.00%
Extinguishment of debt, amount								132,700
Loss on debt extinguishment								8,300
Repayment of long-term debt								150,700
Reacquisition of convertible junior subordinated debentures-equity component								$ 6,300
Accumulated other comprehensive loss
Debt Instrument [Line Items]
Cumulative effect to reclassify certain tax effects from accumulated other comprehensive loss		$ (10,400)					$ (10,422)
Retained earnings
Debt Instrument [Line Items]
Cumulative effect to reclassify certain tax effects from accumulated other comprehensive loss		$ 10,400					$ 10,422

Statutory Information (Details)	12 Months Ended
Statutory Information (Details)	Dec. 31, 2018 USD ($) jurisdiction	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Statutory Capital [Abstract]
Percentage of premiums earned required to be maintained as contingency loss reserves (in hundredths)	50.00%
Period that contingency loss reserves must be held (in years)	10 years
Percentage of net premiums earned that incurred losses must exceed to enable early withdrawals from contingency loss reserves (in hundredths)	35.00%
Related Party Transaction [Line Items]
Statutory net income	$ 375,484,000	$ 310,776,000	$ 106,326,000
Statutory policyholders' surplus	1,683,058,000	1,622,115,000	1,506,475,000
Contingency reserve	$ 2,442,996,000	1,896,701,000	1,360,088,000
Statutory capital requirements [Abstract]
Number of jurisdictions with risk-to-capital requirements \| jurisdiction	16
Maximum permitted risk-to-capital ratio commonly applied	25 to 1
Risk-to-capital ratio on a combined basis at end of period	9.8 to 1
Risk-to-capital ratio on combined insurance operations	9.8
Maximum
Statutory capital requirements [Abstract]
Risk to capital ratio	25
Insurance Subsidiaries
Related Party Transaction [Line Items]
Distributions from other insurance subsidiaries to the parent company	$ 0	0	52,001,000
Statutory capital requirements [Abstract]
Percentage of statutory policyholders surplus used to determine maximum allowable dividends	10.00%
Adjusted statutory net income measurement period	3 years
Adjusted statutory net income dividend payment measurement period	2 years
Mortgage Guaranty Insurance Corporation
Related Party Transaction [Line Items]
Loss ratio	4.00%
Statutory net income	$ 325,000,000
Statutory policyholders' surplus	1,682,000,000
Additions to the surplus of MGIC from parent company funds	0	0	36,025,000
Dividends paid to the parent company	$ 220,000,000	$ 140,000,000	$ 64,000,000
Statutory capital requirements [Abstract]
Risk to capital ratio	9.0
Risk to capital ratio at end of period	9.0 to 1
Amount of policyholders position above or below required MPP	$ 2,600,000,000
Amount of required MPP	1,300,000,000
Reduction in statutory net income due to increase in contingency reserve	$ 484,000,000

Share-based Compensation Plans (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 20.9	$ 14.9	$ 11.4
Income tax benefit from compensation cost	$ 3.0	$ 5.2	$ 4.0
Shares [Roll Forward]
Restricted stock outstanding at end of period (in shares)	3,600,000
Restricted Stock/Restricted Stock Units
Weighted average grant date fair market value [Abstract]
Restricted stock outstanding at end of period (in dollars per share)	$ 8.78
Granted (in dollars per share)	15.69	$ 10.41	$ 5.66
Vested (in dollars per share)	7.81
Forfeited (in dollars per share)	13.28
Restricted stock outstanding at end of period (in dollars per share)	$ 12.27	$ 8.78
Shares [Roll Forward]
Restricted stock outstanding at beginning of period (in shares)	3,300,609
Granted (in shares)	1,685,264
Vested (in shares)	(1,371,063)
Forfeited (in shares)	(31,304)
Restricted stock outstanding at end of period (in shares)	3,583,506	3,300,609
Additional disclosures [Abstract]
Restricted stock, performance shares (in shares)	2,700,000
Restricted stock, time vested shares (in shares)	900,000
Total fair value of restricted stock vested	$ 19.1	$ 15.3	$ 12.2
Unrecognized compensation cost	18.0
Unrecognized compensation cost, performance shares	12.4
Unrecognized compensation cost, time vested shares	$ 5.6
Weighted-average period for recognition of compensation cost	1 year 9 months 18 days
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares can be awarded under the plan (in shares)	10,000,000
Shares available for future grants (in shares)	5,100,000
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Leases [Abstract]
Remaining term of operating leases (in years)	4 years
Minimum future operating lease payments [Abstract]
2019	$ 1,406
2020	1,069
2021	371
2022	161
2023 and thereafter	0
Total	3,007
Total rental expense under operating leases	$ 1,900	$ 2,000	$ 2,100

Unaudited Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Net premiums earned	$ 245,665	$ 250,426	$ 246,964	$ 232,107	$ 237,425	$ 237,083	$ 231,136	$ 229,103	$ 975,162	$ 934,747	$ 925,226
Investment income, net of expenses	38,328	36,380	34,502	32,121	31,276	30,402	29,716	29,477	141,331	120,871	110,666
Realized (losses) gains	(241)	1,114	(1,897)	(329)	458	(50)	(52)	(125)	(1,353)	231	8,921
Other revenue	1,881	2,525	2,431	1,871	2,343	2,925	2,512	2,425	8,708	10,205	17,670
Loss incurred, net	27,685	(1,518)	(13,455)	23,850	(30,996)	29,747	27,339	27,619	36,562	53,709	240,157
Underwriting and other expenses, net	63,239	60,069	57,933	61,895	57,042	56,146	55,292	59,304	243,136	227,784
Loss on debt extinguishment					0	0	65	0	0	65	90,531
Provision for income tax	36,963	49,994	50,708	36,388	218,142	64,440	61,994	84,159	174,053	428,735	172,197
Net income	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 27,314	$ 120,027	$ 118,622	$ 89,798	$ 670,097	$ 355,761	$ 342,517
Earnings per Share [Abstract]
Basic (in dollars per share)	$ 0.44	$ 0.50	$ 0.51	$ 0.39	$ 0.07	$ 0.32	$ 0.32	$ 0.26	$ 1.83	$ 0.98	$ 1.00
Diluted (in dollars per share)	$ 0.43	$ 0.49	$ 0.49	$ 0.38	$ 0.07	$ 0.32	$ 0.31	$ 0.24	$ 1.78	$ 0.95	$ 0.86

SCHEDULE I - SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	$ 5,200,777
Fair Value	5,155,919
Amount at which shown in the balance sheet	5,155,919
Fixed income
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	5,196,784
Fair Value	5,151,987
Amount at which shown in the balance sheet	5,151,987
Fixed income \| U.S. Treasury securities and obligations of U.S. government corporations and agencies
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	167,655
Fair Value	167,176
Amount at which shown in the balance sheet	167,176
Fixed income \| Obligations of U.S. states and political subdivisions
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	1,701,826
Fair Value	1,720,100
Amount at which shown in the balance sheet	1,720,100
Fixed income \| Public utilities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	212,584
Fair Value	208,381
Amount at which shown in the balance sheet	208,381
Fixed income \| ABS
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	111,953
Fair Value	112,033
Amount at which shown in the balance sheet	112,033
Fixed income \| Collateralized loan obligations
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	310,587
Fair Value	305,295
Amount at which shown in the balance sheet	305,295
Fixed income \| Mortgage-backed
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	465,590
Fair Value	446,621
Amount at which shown in the balance sheet	446,621
Fixed income \| All other corporate bonds
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	2,226,589
Fair Value	2,192,381
Amount at which shown in the balance sheet	2,192,381
Equity Securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	3,993
Fair Value	3,932
Amount at which shown in the balance sheet	3,932
Equity Securities \| Industrial, miscellaneous and all other
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amortized Cost	3,993
Fair Value	3,932
Amount at which shown in the balance sheet	$ 3,932

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Fixed income, available-for-sale, at fair value (amortized cost, 2018 – $203,743; 2017 – $195,846)	$ 5,151,987				$ 4,983,315				$ 5,151,987	$ 4,983,315
Cash and cash equivalents	151,892				99,851				151,892	99,851
Accrued investment income	48,001				46,060				48,001	46,060
Other assets	85,572				78,478				85,572	78,478
Total assets	5,677,802				5,619,499				5,677,802	5,619,499
Liabilities:
Senior notes	419,713				418,560				419,713	418,560
Convertible junior subordinated debentures	256,872				256,872				256,872	256,872
Other liabilities	180,322				255,972				180,322	255,972
Total liabilities	2,095,911				2,464,973				2,095,911	2,464,973
Shareholders’ equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2018 - 371,353; 2017 - 370,567; outstanding 2018 - 355,371; 2017 - 370,567)	371,353				370,567				371,353	370,567
Paid-in capital	1,862,536				1,850,582				1,862,536	1,850,582
Treasury stock (shares at cost 2018 – 15,982)	(175,059)				0				(175,059)	0
Accumulated other comprehensive loss, net of tax	(124,214)				(43,783)				(124,214)	(43,783)
Retained earnings	1,647,275				977,160				1,647,275	977,160
Total shareholders' equity	3,581,891				3,154,526				3,581,891	3,154,526	$ 2,548,842
Total liabilities and shareholders' equity	5,677,802				5,619,499				5,677,802	5,619,499
Parenthetical information [Abstract]
Fixed income, amortized cost	$ 5,196,784				$ 4,946,278				$ 5,196,784	$ 4,946,278
Common stock, par value (in dollars per share)	$ 1				$ 1				$ 1	$ 1
Common stock, shares authorized (in shares)	1,000,000,000				1,000,000,000				1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	371,353,000				370,567,000				371,353,000	370,567,000
Common stock, shares outstanding (in shares)	355,371,000				370,567,000				355,371,000	370,567,000
Treasury stock, shares at cost (in shares)	15,982,000				0				15,982,000	0
Revenues:
Investment income, net of expenses	$ 38,328	$ 36,380	$ 34,502	$ 32,121	$ 31,276	$ 30,402	$ 29,716	$ 29,477	$ 141,331	$ 120,871	110,666
Realized (losses) gains	(241)	1,114	(1,897)	(329)	458	(50)	(52)	(125)	(1,353)	231	8,921
Total revenues									1,123,848	1,066,054	1,062,483
Expenses:
Interest expense									52,993	57,035	56,672
Loss on debt extinguishment					0	0	65	0	0	65	90,531
Total losses and expenses									279,698	281,558	547,769
Income before tax									844,150	784,496	514,714
Provision for income taxes	36,963	49,994	50,708	36,388	218,142	64,440	61,994	84,159	174,053	428,735	172,197
Net income	157,746	181,900	186,814	143,637	27,314	120,027	118,622	89,798	670,097	355,761	342,517
Other comprehensive (loss) income, net of tax									(80,413)	41,739	(14,220)
Comprehensive income									589,684	397,500	328,297
Cash flows from operating activities:
Net income	157,746	$ 181,900	$ 186,814	143,637	27,314	120,027	118,622	89,798	670,097	355,761	342,517
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred Federal									185,598	351,677	160,657
Loss on debt extinguishment					0	$ 0	$ 65	0	0	65	90,531
Change in certain assets and liabilities:
Accrued investment income									(1,941)	(1,987)	(3,849)
Net cash provided by operating activities									544,517	406,657	224,760
Cash flows from investing activities:
Net cash used in investing activities									(317,780)	(303,641)	(93,392)
Cash flows from financing activities:
Proceeds from revolving credit facility									0	150,000	0
Repayment of revolving credit facility									0	(150,000)	0
Proceeds from issuance of long-term debt									0	0	573,094
Purchase or repayment of convertible senior notes									0	(145,620)	(363,778)
Repurchase of common stock									(163,419)	0	(147,127)
Payment of debt issuance costs									0	(1,630)	(1,127)
Payment of withholding taxes related to share-based compensation net share settlement									(8,131)	(6,821)	(5,030)
Net cash used in financing activities									(171,550)	(158,575)	(157,078)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents									55,187	(55,559)	(25,710)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year				99,851				155,410	99,851	155,410	181,120
Cash and cash equivalents and restricted cash and cash equivalents at end of year	155,038				99,851				155,038	99,851	155,410
Parent Company
Assets
Fixed income, available-for-sale, at fair value (amortized cost, 2018 – $203,743; 2017 – $195,846)	201,507				194,061				201,507	194,061
Cash and cash equivalents	46,502				22,247				46,502	22,247
Investment in subsidiaries, at equity in net assets	3,981,970				3,567,034				3,981,970	3,567,034
Accounts receivable - affiliates	1,396				1,414				1,396	1,414
Income taxes - current and deferred	186,561				192,570				186,561	192,570
Accrued investment income	2,020				1,941				2,020	1,941
Other assets	740				1,275				740	1,275
Total assets	4,420,696				3,980,542				4,420,696	3,980,542
Liabilities:
Senior notes	419,713				418,560				419,713	418,560
Convertible junior subordinated debentures	389,522				389,522				389,522	389,522
Accrued interest	17,930				17,934				17,930	17,934
Other liabilities	11,640				0				11,640	0
Total liabilities	838,805				826,016				838,805	826,016
Shareholders’ equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2018 - 371,353; 2017 - 370,567; outstanding 2018 - 355,371; 2017 - 370,567)	371,353				370,567				371,353	370,567
Paid-in capital	1,862,536				1,850,582				1,862,536	1,850,582
Treasury stock (shares at cost 2018 – 15,982)	(175,059)				0				(175,059)	0
Accumulated other comprehensive loss, net of tax	(124,214)				(43,783)				(124,214)	(43,783)
Retained earnings	1,647,275				977,160				1,647,275	977,160
Total shareholders' equity	3,581,891				3,154,526				3,581,891	3,154,526
Total liabilities and shareholders' equity	4,420,696				3,980,542				4,420,696	3,980,542
Parenthetical information [Abstract]
Fixed income, amortized cost	$ 203,743				$ 195,846				$ 203,743	$ 195,846
Common stock, par value (in dollars per share)	$ 1				$ 1				$ 1	$ 1
Common stock, shares authorized (in shares)	1,000,000,000				1,000,000,000				1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	371,353,000				370,567,000				371,353,000	370,567,000
Common stock, shares outstanding (in shares)	355,371,000				370,567,000				355,371,000	370,567,000
Treasury stock, shares at cost (in shares)	15,982,000				0				15,982,000	0
Revenues:
Investment income, net of expenses									$ 4,685	$ 3,177	3,807
Realized (losses) gains									(532)	(13)	646
Total revenues									4,153	3,164	4,453
Expenses:
Operating expenses									637	642	1,409
Interest expense									61,930	65,972	64,598
Loss on debt extinguishment									0	65	82,234
Total losses and expenses									62,567	66,679	148,241
Income before tax									(58,414)	(63,515)	(143,788)
Provision for income taxes									(13,517)	95,517	(52,575)
Equity in net income of subsidiaries									714,994	514,793	433,730
Net income									670,097	355,761	342,517
Other comprehensive (loss) income, net of tax									(80,413)	41,739	(14,220)
Comprehensive income									589,684	397,500	328,297
Cash flows from operating activities:
Net income									670,097	355,761	342,517
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of subsidiaries									(714,994)	(514,793)	(433,730)
Dividends received from subsidiaries									199,692	110,145	64,000
Deferred Federal									(11,756)	96,741	(55,988)
Loss on debt extinguishment									0	65	82,234
Other									24,303	18,716	16,722
Change in certain assets and liabilities:
Accounts receivable - affiliates									18	(634)	158
Income taxes receivable									17,859	297	3,602
Accrued investment income									112	(192)	1,951
Accrued interest									(4)	(2,819)	6,811
Net cash provided by operating activities									185,327	63,287	28,277
Cash flows from investing activities:
Capital distributions from subsidiaries									0	0	51,987
Capital contributions to subsidiaries									0	0	(36,025)
Purchases of investments									(83,003)	(97,091)	(194,751)
Proceeds from sales of investments									93,481	176,960	330,142
Net cash used in investing activities									10,478	79,869	151,353
Cash flows from financing activities:
Proceeds from revolving credit facility									0	150,000	0
Repayment of revolving credit facility									0	(150,000)	0
Proceeds from issuance of long-term debt									0	0	418,094
Purchase or repayment of convertible senior notes									0	(150,124)	(426,191)
Repurchase of common stock									(163,419)	0	(147,127)
Payment of debt issuance costs									0	(1,630)	(1,127)
Payment of withholding taxes related to share-based compensation net share settlement									(8,131)	(6,821)	(5,030)
Net cash used in financing activities									(171,550)	(158,575)	(161,381)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents									24,255	(15,419)	18,249
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year				$ 22,247				$ 37,666	22,247	37,666	19,417
Cash and cash equivalents and restricted cash and cash equivalents at end of year	$ 46,502				$ 22,247				$ 46,502	$ 22,247	$ 37,666

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - SUPPLEMENTARY NOTES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Insurance Subsidiaries
Supplementary Insurance Information, by Segment [Line Items]
Percentage of statutory policyholders surplus used to determine maximum allowable dividends	10.00%
Adjusted statutory net income measurement period	3 years
Adjusted statutory net income dividend payment measurement period	2 years
Distributions from other insurance subsidiaries to the parent company	$ 0	$ 0	$ 52,001,000
Proceeds from contribution from parent	$ 0	0
Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
Supplementary Insurance Information, by Segment [Line Items]
Stated interest rate (in hundredths)	9.00%
Mortgage Guaranty Insurance Corporation
Supplementary Insurance Information, by Segment [Line Items]
Dividends paid to the parent company	$ 220,000,000	140,000,000	64,000,000
Additions to the surplus of MGIC from parent company funds	0	$ 0	$ 36,025,000
Mortgage Guaranty Insurance Corporation \| Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
Supplementary Insurance Information, by Segment [Line Items]
Investment in holding company debt	$ 132,700,000

SCHEDULE IV - REINSURANCE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]
Gross Amount	$ 1,084,748	$ 1,059,973	$ 1,058,545
Ceded to Other Companies	111,391	125,735	133,981
Assumed From Other Companies	1,805	509	662
Net Amount	$ 975,162	$ 934,747	$ 925,226
Percentage of Amount Assumed to Net	0.20%	0.10%	0.10%

Nature of Business (Details) $ in Billions	Dec. 31, 2018 USD ($)
Nature of Business [Abstract]
Direct domestic primary insurance in force	$ 209.7
Direct domestic primary risk in force	$ 54.1

Litigation and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Average paid claim reduction due to curtailments (in hundredths)	5.80%	5.60%
Maximum exposure to loss	$ 279

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	$ 5,151,987	$ 4,983,315
Equity securities, at fair value	3,932
Other	96,403
Real estate acquired	14,535	12,713
Total assets	5,266,857	5,003,274
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	96,403
Real estate acquired	0	0
Total assets	142,599	84,576
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	0
Real estate acquired	0	0
Total assets	5,109,710	4,901,446
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	0
Real estate acquired	14,535	12,713
Total assets	14,548	17,252
Total fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	5,151,987	4,983,315
Total fixed income securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	42,264	81,598
Total fixed income securities \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	5,109,710	4,901,446
Total fixed income securities \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	13	271
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	167,176	178,846
U.S. Treasury securities and obligations of U.S. government corporations and agencies \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	42,264	81,598
U.S. Treasury securities and obligations of U.S. government corporations and agencies \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	124,912	97,248
U.S. Treasury securities and obligations of U.S. government corporations and agencies \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
Obligations of U.S. states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	1,720,100	2,152,524
Obligations of U.S. states and political subdivisions \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
Obligations of U.S. states and political subdivisions \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	1,720,087	2,152,253
Obligations of U.S. states and political subdivisions \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	13	271
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	2,400,762	2,066,838
Corporate debt securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
Corporate debt securities \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	2,400,762	2,066,838
Corporate debt securities \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
ABS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	112,033	4,923
ABS \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
ABS \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	112,033	4,923
ABS \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
RMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	178,961	181,849
RMBS \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
RMBS \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	178,961	181,849
RMBS \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
CMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	267,660	297,312
CMBS \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
CMBS \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	267,660	297,312
CMBS \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
CLOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	305,295	101,023
CLOs \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
CLOs \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	305,295	101,023
CLOs \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	0	0
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		7,246
Equity securities, at fair value	3,932
Equity securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		2,978
Equity securities, at fair value	3,932
Equity securities \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		0
Equity securities, at fair value	0
Equity securities \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		$ 4,268
Equity securities, at fair value	$ 0