MGIC Investment (MTG) 10-K24 Feb 202019 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2019	Feb. 14, 2020	Jun. 30, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-10816
Entity Registrant Name	MGIC Investment Corp
Entity Incorporation, State or Country Code	WI
Entity Tax Identification Number	39-1486475
Entity Address, Address Line One	250 E. Kilbourn Avenue
Entity Address, Postal Zip Code	53202
Entity Address, City or Town	Milwaukee,
Entity Address, State or Province	WI
City Area Code	(414)
Local Phone Number	347-6480
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 4.6
Entity Common Stock, Shares Outstanding		345,852,631
Documents Incorporated by Reference	ed: Document Part and Item Number of Form 10-K Into Which Incorporated* Proxy Statement for the 2020 Annual Meeting of Shareholders, provided such Proxy Statement is filed within 120 days after December 31, 2019. If not so filed, the information provided in Items 10 through 14 of Part III will be included in an amended Form 10-K filed within such 120 day period. Items 10 through 14 of Part III
Entity Central Index Key	0000876437
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Common stock \| NEW YORK STOCK EXCHANGE, INC.
Entity Information [Line Items]
Title of 12(b) Security	Common stock, par value $1 per share
Trading Symbol	MTG
Security Exchange Name	NYSE
Common Share Purchase Rights \| NEW YORK STOCK EXCHANGE, INC.
Entity Information [Line Items]
Title of 12(b) Security	Common share purchase rights
Security Exchange Name	NYSE
No Trading Symbol Flag	true

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investment portfolio:
Fixed income, available-for-sale, at fair value (amortized cost, 2019 - $5,562,550; 2018 - $5,196,784)	$ 5,737,892	$ 5,151,987
Equity securities, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	17,328	3,932
Other invested assets, at cost	3,100	3,100
Total investment portfolio	5,758,320	5,159,019
Cash and cash equivalents	161,847	151,892
Restricted cash and cash equivalents	7,209	3,146
Accrued investment income	49,705	48,001
Reinsurance recoverable on loss reserves	21,641	33,328
Reinsurance recoverable on paid losses	1,521	2,948
Premiums receivable	55,587	55,090
Home office and equipment, net	50,121	51,734
Deferred insurance policy acquisition costs	18,531	17,888
Deferred income taxes, net	5,742	69,184
Other assets	99,347	85,572
Total assets	6,229,571	5,677,802
Liabilities:
Loss reserves	555,334	674,019
Unearned premiums	380,302	409,985
Federal Home Loan Bank Advance	155,000	155,000
Senior notes	420,867	419,713
Convertible junior subordinated debentures	256,872	256,872
Other liabilities	151,962	180,322
Total liabilities	1,920,337	2,095,911
Contingencies
Shareholders' equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2019 - 371,353; 2018 - 371,353; outstanding 2019 - 347,308; 2018 - 355,371)	371,353	371,353
Paid-in capital	1,869,719	1,862,536
Treasury stock (shares at cost 2019 - 24,045; 2018 - 15,982)	(283,196)	(175,059)
Accumulated other comprehensive income (loss), net of tax	72,708	(124,214)
Retained earnings	2,278,650	1,647,275
Total shareholders' equity	4,309,234	3,581,891
Total liabilities and shareholders' equity	$ 6,229,571	$ 5,677,802

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed income, amortized cost	$ 5,562,550	$ 5,196,784
Equity securities, cost	$ 17,188	$ 3,993
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	371,353,000
Common stock, shares outstanding (in shares)	347,308,000	355,371,000
Treasury stock, shares at cost (in shares)	24,045,000	15,982,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Premiums written:
Direct	$ 1,124,196	$ 1,103,332	$ 1,121,776
Assumed	6,446	271	1,905
Ceded	(129,334)	(111,341)	(125,726)
Net premiums written	1,001,308	992,262	997,955
Decrease (increase) in unearned premiums	29,680	(17,100)	(63,208)
Net premiums earned	1,030,988	975,162	934,747
Investment income, net of expenses	167,045	141,331	120,871
Net realized investment gains (losses)	5,306	(1,353)	231
Other revenue	10,638	8,708	10,205
Total revenues	1,213,977	1,123,848	1,066,054
Losses and expenses:
Losses incurred, net	118,575	36,562	53,709
Amortization of deferred policy acquisition costs	12,001	11,932	11,111
Other underwriting and operating expenses, net	182,768	178,211	159,638
Interest expense	52,656	52,993	57,035
Loss on debt extinguishment	0	0	65
Total losses and expenses	366,000	279,698	281,558
Income before tax	847,977	844,150	784,496
Provision for income taxes	174,214	174,053	428,735
Net income	$ 673,763	$ 670,097	$ 355,761
Earnings per share:
Basic (in dollars per share)	$ 1.91	$ 1.83	$ 0.98
Diluted (in dollars per share)	$ 1.85	$ 1.78	$ 0.95
Weighted average common shares outstanding - basic (in shares)	352,827	365,406	362,380
Weighted average common shares outstanding - diluted (in shares)	373,924	386,078	394,766

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 177,110	$ 176,934	$ 167,778	$ 151,941	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 673,763	$ 670,097	$ 355,761
Other comprehensive income (loss), net of tax:
Change in unrealized investment gains and losses									173,910	(64,646)	47,547
Benefit plans adjustment									23,012	(15,767)	(5,839)
Foreign currency translation adjustment									0	0	31
Other comprehensive income (loss), net of tax									196,922	(80,413)	41,739
Comprehensive income									$ 870,685	$ 589,684	$ 397,500

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common stock	Paid-in capital	Treasury stock	Accumulated other comprehensive loss	Retained earnings	ASU 2016-09Paid-in capital	ASU 2016-09Retained earnings	ASU 2016-01Accumulated other comprehensive loss	ASU 2016-01Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting standard update							$ 49	$ 153
Balance, beginning of year at Dec. 31, 2016		$ 359,400	$ 1,782,337	$ (150,359)	$ (75,100)	$ 632,564
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock		10,386	60,903
Net common stock issued under share-based compensation plans		781	(7,602)
Equity compensation			14,895
Purchases of common stock				0
Reissuance of treasury stock, net				150,359		(21,740)
Other comprehensive income (loss)	$ 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)	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
Net common stock issued under share-based compensation plans		786	(8,917)
Equity compensation			20,871
Purchases of common stock				(175,059)
Other comprehensive income (loss)	(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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			(11,715)	5,989
Equity compensation			18,898
Purchases of common stock				(114,126)
Other comprehensive income (loss)	196,922				196,922
Net income	673,763					673,763
Cash dividends						(42,388)
Balance, end of year at Dec. 31, 2019	$ 4,309,234	$ 371,353	$ 1,869,719	$ (283,196)	$ 72,708	$ 2,278,650

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 673,763	$ 670,097	$ 355,761
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and other amortization	48,784	58,215	64,430
Deferred tax expense	11,096	186,572	355,044
Net realized investment (gains) losses	(5,306)	1,353	(231)
Loss on debt extinguishment	0	0	65
Change in certain assets and liabilities:
Accrued investment income	(1,704)	(1,941)	(1,987)
Reinsurance recoverable on loss reserves	11,687	15,146	2,019
Reinsurance recoverable on paid losses	1,427	924	1,092
Premiums receivable	(497)	(1,045)	(1,653)
Deferred insurance policy acquisition costs	(643)	953	(1,082)
Profit commission receivable	4,945	(5,479)	(2,844)
Loss reserves	(118,685)	(311,616)	(453,178)
Unearned premiums	(29,683)	17,051	63,197
Return premium accrual	(11,500)	(22,900)	(25,400)
Current income taxes	1,057	(77,551)	51,296
Other, net	24,791	14,738	128
Net cash provided by operating activities	609,532	544,517	406,657
Cash flows from investing activities:
Purchases of investments	(1,394,126)	(1,459,473)	(1,293,695)
Proceeds from sales of investments	229,796	370,449	246,908
Proceeds from maturity of fixed income securities	748,165	785,175	759,212
Net (decrease) increase in payables for securities	(307)	307	0
Additions to property and equipment	(5,636)	(14,238)	(16,066)
Net cash used in investing activities	(422,108)	(317,780)	(303,641)
Cash flows from financing activities:
Proceeds from revolving credit facility	0	0	150,000
Repayment of revolving credit facility	0	0	(150,000)
Purchase or repayment of convertible senior notes	0	0	(145,620)
Payment of original issue discount - convertible senior notes	0	0	(4,504)
Repurchase of common stock	(125,766)	(163,419)	0
Dividends paid	(41,914)	0	0
Payment of debt issuance costs	0	0	(1,630)
Payment of withholding taxes related to share-based compensation net share settlement	(5,726)	(8,131)	(6,821)
Net cash used in financing activities	(173,406)	(171,550)	(158,575)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents	14,018	55,187	(55,559)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year	155,038	99,851	155,410
Cash and cash equivalents and restricted cash and cash equivalents at end of year	$ 169,056	$ 155,038	$ 99,851

Nature of Business

Nature of Business	12 Months Ended
Nature of Business	Dec. 31, 2019
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, 2019 , our direct primary insurance in force ("IIF") was $222.3 billion , which represents the principal balance in our records of all mortgage loans that we insure, and our direct primary risk in force ("RIF") was $57.2 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. The current private mortgage insurer eligibility requirements ("PMIERs") of the GSEs include financial requirements, as well as business, quality control and certain transactional approval requirements. 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 of insurance in force, calculated from tables of factors with several risk dimensions, reduced for credit given for risk ceded under reinsurance transactions, and subject to a floor amount). Based on our interpretation of the more restrictive application of the PMIERs, as of December 31, 2019 , MGIC’s Available Assets are in excess of its Minimum Required Assets; and MGIC is in compliance with the PMIERs and eligible to insure loans purchased by the GSEs.

Basis of Presentation

Basis of Presentation	12 Months Ended
Basis of Presentation	Dec. 31, 2019
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 2018 and 2017 amounts have been made in the accompanying consolidated financial statements to conform to the 2019 presentation. See Note 3 - "Significant Accounting Policies" for a discussion of our adoption of accounting guidance in 2019 that resulted in other reclassifications.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
Significant Accounting Policies	Dec. 31, 2019
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 and cash equivalents. 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. 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. Equity securities are reported at fair value, except for certain securities that are carried at cost. Equity securities carried at cost are reported as Other invested assets. Effective January 1, 2018, realized investment gains and losses, after considering the related tax expense or benefit, are accounted for as a function of the periodic change in fair value. For 2017, realized investment gains and losses were accounted for as 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 $43.0 million , $38.1 million and $33.9 million as of December 31, 2019 , 2018 and 2017 , respectively. Depreciation expense for the years ended December 31, 2019 , 2018 and 2017 was $6.5 million , $6.0 million and $5.4 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 Case reserves and loss adjustment expenses ("LAE") reserves are established when we receive notices of delinquency on insured mortgage loans. We consider a loan delinquent 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 case reserves for future claims on insured loans which are not currently delinquent. Case 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 case reserve estimates are established based upon historical experience, including 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. Incurred but not reported ("IBNR") 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. IBNR reserves are also established using estimated claim rates and claim severities. LAE reserves are established for the estimated costs of settling claims, including legal and other expenses and general expenses of administering the claims settlement process. Loss 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 re-underwrite 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 estimated 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. The first step applies a more-likely-than-not threshold for recognition and derecognition. The second step measures the tax position as the greatest amount of benefit that is cumulatively greater than 50% likely to be 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. Federal tax law permits mortgage guaranty insurance companies to deduct from taxable income, subject to certain limitations, the amounts added to contingency loss reserves that are recorded for regulatory purposes. The amounts we deduct must generally be included in taxable income in the tenth subsequent year. The deduction is allowed only to the extent that we purchase and hold U.S. government non-interest-bearing tax and loss bonds in an amount equal to the tax benefit attributable to the deduction. We account for these purchases as a payment of current federal income tax. (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. 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, we had other convertible notes in 2017 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 2019 , 2018 , or 2017 . RECENT ACCOUNTING AND REPORTING DEVELOPMENTS Accounting standards effective in 2019, or early adopted, and relevant to our financial statements Accounting Standard Update (“ASU”) 2016-02 - Leases In February 2016, the FASB amended the previous leasing standard and created ASC 842, Leases. ASC 842 requires a lessee to recognize a right-of-use asset and lease liability for substantially all leases. Effective for the quarter ended March 31, 2019, we adopted the updated guidance for leases and also elected to apply all practical expedients applicable to us in the updated guidance for transition of leases in effect at adoption. The adoption of the updated guidance resulted in the recognition of an immaterial right-of-use asset as part of other assets and a lease liability as part of other liabilities in the consolidated balance sheet. è Adoption impact: The adoption of the updated guidance did not have a material effect on our consolidated results of operations or liquidity. PROSPECTIVE ACCOUNTING STANDARDS Table 3.1 shows the relevant new amendments to accounting standards, which are not yet effective or adopted. Standard / Interpretation Table 3.1 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 ASC 740 Income Taxes • ASU 2019-12 - Simplifying the Accounting for Income Taxes 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. We have concluded that our mortgage insurance policies are outside the scope of this ASU, however, the provisions of this guidance do apply to our reinsurance transactions, which are highly rated, as discussed in Note 9 – “Reinsurance” to our consolidated financial statements. Entities are required to incorporate 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. The allowance for current expected credit losses (“CECL”) generally reduces the amortized cost basis of the financial instrument to the amount an entity expects to collect, however, credit losses relating to available-for-sale fixed maturity securities are to be recorded through an allowance for credit losses, 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. In May 2019, the FASB amended this guidance to provide entities with an option to irrevocably elect the fair value option for eligible instruments in order to provide targeted transition relief that is intended to increase comparability of financial statement information for some entities that otherwise would have measured similar financial instruments using different measurement methodologies. We have evaluated the impacts the adoption of this guidance will have on our consolidated financial statements, and determined it will not have a material impact. 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 requires 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. We have evaluated the impacts the adoption of this guidance will have on our consolidated financial statements, and determined it will not 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 disclosure requirements 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. Simplifying the Accounting for Income Taxes

Earnings per Share

Earnings per Share	12 Months Ended
Earnings per Share	Dec. 31, 2019
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) 2019 2018 2017 Basic earnings per share: Net income $ 673,763 $ 670,097 $ 355,761 Weighted average common shares outstanding - basic 352,827 365,406 362,380 Basic earnings per share $ 1.91 $ 1.83 $ 0.98 Diluted earnings per share: Net income $ 673,763 $ 670,097 $ 355,761 Interest expense, net of tax (1) : 2% Notes — — 907 5% Notes — — 1,709 9% Debentures 18,264 18,264 15,027 Diluted income available to common shareholders $ 692,027 $ 688,361 $ 373,404 Weighted-average shares - basic 352,827 365,406 362,380 Effect of dilutive securities: Unvested restricted stock units 2,069 1,644 1,493 2% Notes — — 8,317 5% Notes — — 3,548 9% Debentures 19,028 19,028 19,028 Weighted average common shares outstanding - diluted 373,924 386,078 394,766 Diluted income per share $ 1.85 $ 1.78 $ 0.95 (1) Interest expense for the years ended December 31, 2019 , 2018 and 2017 has been tax effected at a rate of 21% , 21% , and 35% , respectively. For the years ended December 31, 2019 , 2018

Investments

Investments	12 Months Ended
Investments	Dec. 31, 2019
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, 2019 and 2018 are shown below: Details of fixed income investment securities by category as of December 31, 2019 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 $ 195,176 $ 1,237 $ (210 ) $ 196,203 Obligations of U.S. states and political subdivisions 1,555,394 99,328 (857 ) 1,653,865 Corporate debt securities 2,711,910 76,220 (3,008 ) 2,785,122 ABS 227,376 2,466 (178 ) 229,664 RMBS 271,384 429 (3,227 ) 268,586 CMBS 274,234 5,531 (779 ) 278,986 CLOs 327,076 33 (1,643 ) 325,466 Total fixed income securities $ 5,562,550 $ 185,244 $ (9,902 ) $ 5,737,892 Details of fixed income investment securities by category as of December 31, 2018 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 $ 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 (1) There were no OTTI losses recorded in other comprehensive (loss) income as of December 31, 2019 and 2018 . The increase in gross unrealized gains and the decrease in gross unrealized losses in our fixed income securities from December 31, 2018 to December 31, 2019 were primarily caused by declines in interest rates during that period. We had $13.9 million and $13.5 million of investments at fair value on deposit with various states as of December 31, 2019 and 2018 , respectively, due to regulatory requirements of those states' 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 $89.9 million and $26.3 million at December 31, 2019 and 2018 , respectively. Table 5.2 compares the amortized cost and fair values of fixed income securities, by contractual maturity, as of December 31, 2019 . 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, 2019 (In thousands) Amortized Cost Fair Value Due in one year or less $ 425,739 $ 427,616 Due after one year through five years 1,911,433 1,952,278 Due after five years through ten years 1,031,056 1,088,012 Due after ten years 1,094,252 1,167,284 4,462,480 4,635,190 ABS 227,376 229,664 RMBS 271,384 268,586 CMBS 274,234 278,986 CLOs 327,076 325,466 Total as of December 31, 2019 $ 5,562,550 $ 5,737,892 Proceeds from the sale of fixed income securities classified as available-for-sale were $228.1 million , $365.6 million , and $246.9 million during the years ended December 31, 2019 , 2018 , and 2017 , respectively. Gross gains of $7.1 million , $0.7 million , and $1.6 million and gross losses of $3.5 million , $3.8 million and $1.4 million were realized on those sales during the years ended December 31, 2019 , 2018 , and 2017 , respectively. For the years ended December 31, 2019 and December 31, 2018 , we recorded $0.1 million and $1.8 million of OTTI losses in earnings, respectively. For the year ended December 31, 2017 , there were no OTTI losses in earnings. EQUITY SECURITIES The cost and fair value of investments in equity securities as of December 31, 2019 and December 31, 2018 are shown in tables 5.3a and 5.3b below. 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. Details of equity investment securities as of December 31, 2019 Table 5.3a (In thousands) Cost Gross gains Gross losses Fair Value Equity securities 17,188 154 (14 ) 17,328 Details of equity investment securities as of December 31, 2018 Table 5.3b (In thousands) Cost Gross gains Gross losses Fair Value Equity securities 3,993 11 (72 ) 3,932 Proceeds from the sale of equity securities were $1.7 million and $4.9 million during the years ended December 31, 2019 and 2018 , respectively. Gross gains of $1.6 million and $3.7 million were realized on those sales during the year ended December 31, 2019 and 2018 , respectively. There were no sales of equity securities in 2017. For the year ended December 31, 2019 and December 31, 2018 , we recognized $201 thousand and $84 thousand of net losses on equity securities still held as of December 31, 2019 and December 31, 2018 , respectively, 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 Federal Home Loan Bank ("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, 2019 , that collateral consisted of fixed income securities included in our total investment portfolio, and cash and cash equivalents, with a total fair value of $165.7 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, 2019 and 2018 , 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 $10 million and $78 million as of December 31, 2019 and 2018 , 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, 2019 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 $ 57,301 $ (200 ) $ 5,806 $ (10 ) $ 63,107 $ (210 ) Obligations of U.S. states and political subdivisions 74,859 (847 ) 6,957 (10 ) 81,816 (857 ) Corporate debt securities 221,357 (2,847 ) 43,505 (161 ) 264,862 (3,008 ) ABS 21,542 (118 ) 3,851 (60 ) 25,393 (178 ) RMBS 105,443 (461 ) 110,452 (2,766 ) 215,895 (3,227 ) CMBS 62,388 (728 ) 11,852 (51 ) 74,240 (779 ) CLOs 81,444 (225 ) 196,988 (1,418 ) 278,432 (1,643 ) Total $ 624,334 $ (5,426 ) $ 379,411 $ (4,476 ) $ 1,003,745 $ (9,902 ) Unrealized loss aging for securities by type and length of time as of December 31, 2018 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 $ 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 ) 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, 2019 and 2018 were primarily caused by changes in interest rates between the time of purchase and the respective year end. There were 217 and 721 securities in an unrealized loss position as of December 31, 2019 and 2018 , respectively. As of December 31, 2019 , the fair value as a percent of amortized cost of the securities in an unrealized loss position was 99% and approximately 28% 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) 2019 2018 2017 Fixed income securities $ 165,523 $ 140,539 $ 122,105 Equity securities 406 228 206 Cash equivalents 4,444 3,423 1,447 Other 974 816 620 Investment income 171,347 145,006 124,378 Investment expenses (4,302 ) (3,675 ) (3,507 ) Net investment income $ 167,045 $ 141,331 $ 120,871 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) 2019 2018 2017 Fixed income securities $ 220,139 $ (81,834 ) $ 69,026 Equity securities — — 39 Other — — (13 ) Change in unrealized gains/losses $ 220,139 $ (81,834 ) $ 69,052

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2019
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 • Real estate acquired are valued at 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. RECURRING FAIR VALUE MEASUREMENTS Assets carried at fair value included those listed, by hierarchy level, in the following tables as of December 31, 2019 and 2018 : Assets carried at fair value by hierarchy level as of December 31, 2019 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 $ 196,203 $ 34,240 $ 161,963 $ — Obligations of U.S. states and political subdivisions 1,653,865 — 1,653,865 — Corporate debt securities 2,785,122 — 2,785,122 — ABS 229,664 — 229,664 — RMBS 268,586 — 268,586 — CMBS 278,986 — 278,986 — CLOs 325,466 — 325,466 — Total fixed income securities 5,737,892 34,240 5,703,652 — Equity securities 17,328 17,328 — — Other (1) 164,693 164,693 — — Real estate acquired (2) 7,252 — — 7,252 Total $ 5,927,165 $ 216,261 $ 5,703,652 $ 7,252 Assets carried at fair value by hierarchy level as of December 31, 2018 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 $ 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) 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 (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) 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, 2019 , 2018 , and 2017 is shown in tables 6.2a , 6.2b and 6.2c below. 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 6.2b 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, 2019 and 2017. There were no losses included in earnings for the years ended December 31, 2019 , 2018 , and 2017 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, 2019 Table 6.2a (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2018 $ 13 $ — $ 13 $ 14,535 Total realized/unrealized gains (losses): Included in earnings and reported as losses incurred, net — — — (476 ) Acquisitions — — — 24,204 Sales (13 ) — (13 ) (31,011 ) Balance at December 31, 2019 $ — $ — $ — $ 7,252 Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2018 Table 6.2b (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2017 $ 271 $ 4,268 $ 4,539 $ 12,713 Reclassification for adoption of new accounting standard — (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 ) Acquisitions — — — 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 6.2c (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 ) Acquisitions — — — 34,749 Sales (420 ) — (420 ) (32,469 ) Balance at December 31, 2017 $ 271 $ 4,268 $ 4,539 $ 12,713 Additional fair value disclosures related to our investment portfolio are included in Note 5 – “Investments. ” FINANCIAL LIABILITIES NOT CARRIED AT FAIR VALUE Other invested assets include an investment in FHLB stock that is carried at cost, which due to restrictions that require it to be redeemed or sold only to the security issuer at par value, approximates fair value. The fair value of other invested assets is categorized as Level 2. Financial liabilities include our outstanding debt obligations. 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 . 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, 2019 and 2018 . Financial liabilities not carried at fair value Table 6.3 December 31, 2019 December 31, 2018 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Financial assets Other invested assets $ 3,100 $ 3,100 $ 3,100 $ 3,100 Financial liabilities FHLB Advance $ 155,000 $ 156,422 $ 155,000 $ 150,551 5.75% Notes 420,867 471,827 419,713 425,791 9% Debentures 256,872 346,289 256,872 338,069 Total financial liabilities $ 832,739 $ 974,538 $ 831,585 $ 914,411 The 5.75% Notes and 9% Debentures are obligations of our holding company, MGIC Investment Corporation, and not of its subsidiaries.

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2019
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, 2019 and 2018 . Long-term debt obligations Table 7.1 December 31, (In millions) 2019 2018 FHLB Advance - 1.91%, due February 2023 $ 155.0 $ 155.0 5.75% Notes, due August 2023 (par value: $425 million) 420.9 419.7 9% Debentures, due April 2063 256.9 256.9 Long-term debt, carrying value $ 832.7 $ 831.6 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. 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 and accrued interest. 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, 2019. 9% Debentures The 9% Debentures are currently convertible, at the holder's option, at an initial conversion rate, which is subject to adjustment, of 74.4718 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 $13.43 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 19.1 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 $17.46 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 ten th 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 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, 2019 . The 9% Debentures rank junior to all of our existing and future senior indebtedness. CREDIT FACILITY In May 2019, we terminated our $175 million unsecured revolving credit facility. At the time of termination there were no amounts drawn on the credit facility. The unused portion of our revolving credit facility was subject to recurring commitment fees, which are reflected in interest payments. INTEREST PAYMENTS Interest payments were $50.8 million during 2019 , $51.3 million during 2018 , and $57.8 million during 2017 .

Loss Reserves

Loss Reserves	12 Months Ended
Loss Reserves	Dec. 31, 2019
Insurance Loss Reserves [Abstract]
Loss Reserves	NOTE 8 Loss Reserves As described in Note 3 – “Summary of Significant Accounting Policies – Loss Reserves,” Case reserves and loss adjustment expenses ("LAE") reserves are established when we receive notices of delinquency on insured mortgage loans. We consider a loan delinquent when it is two or more payments past due. Case 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. IBNR 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. IBNR reserves are also established using estimated claim rates and claim severities 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 delinquency 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 2019 compared to 2018 and in 2018 compared to 2017 , 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 are utilizing 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 $30 million and $40 million at December 31, 2019 and 2018 , respectively. Table 8.1 provides a reconciliation of beginning and ending loss reserves for each of the past three years: Development of loss reserves Table 8.1 (In thousands) 2019 2018 2017 Reserve at beginning of year $ 674,019 $ 985,635 $ 1,438,813 Less reinsurance recoverable 33,328 48,474 50,493 Net reserve at beginning of year 640,691 937,161 1,388,320 Losses incurred: Losses and LAE incurred in respect of delinquent notices received in: Current year 189,581 203,928 284,913 Prior years (1) (71,006 ) (167,366 ) (231,204 ) Total losses incurred 118,575 36,562 53,709 Losses paid: Losses and LAE paid in respect of delinquent notices received in: Current year 4,018 7,298 11,267 Prior years 235,551 327,743 493,300 Reinsurance terminations (13,996 ) (2,009 ) 301 Total losses paid 225,573 333,032 504,868 Net reserve at end of year 533,693 640,691 937,161 Plus reinsurance recoverables 21,641 33,328 48,474 Reserve at end of year $ 555,334 $ 674,019 $ 985,635 (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 2019 , 2018 and 2017 for previously received delinquencies. Reserve development on previously received delinquencies Table 8.2 (In millions) 2019 2018 2017 Decrease in estimated claim rate on primary delinquencies $ (112 ) $ (213 ) $ (248 ) (Decrease) increase in estimated severity on primary delinquencies (1 ) 29 9 Change in estimates related to pool reserves, LAE reserves, reinsurance and other 42 17 8 Total prior year loss development (1) $ (71 ) $ (167 ) $ (231 ) (1) A negative number for prior year loss development indicates a redundancy of prior year loss reserves. For the years ended December 31, 2019 , 2018 and 2017 , we experienced favorable development on previously received delinquencies. This development was, in part, due to the resolution of approximately 69% , 73% and 67% for the years ended December 31, 2019 , 2018 and 2017 , respectively, of the prior year delinquent inventory, with improved cure rates. During 2019, 2018, and 2017, cure activity on loans that were delinquent twelve months or more was significantly higher than our previous estimates. During 2019, the favorable development was offset by adjustments to LAE reserves and amounts paid in settlement of disputes for claim paying practices. See Note 17 – “Litigation and Contingencies.” The favorable development for the years ended 2018 and 2017 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, 2019 , 2018 , and 2017 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 2019 2018 2017 Beginning delinquent inventory 32,898 46,556 50,282 New Notices 54,239 54,448 68,268 Cures (52,035 ) (60,511 ) (61,094 ) Paid claims (4,267 ) (5,750 ) (9,206 ) Rescissions and denials (168 ) (267 ) (357 ) Other items removed from inventory (639 ) (1,578 ) (1,337 ) Ending delinquent inventory 30,028 32,898 46,556 Hurricane activity New delinquent notice activity increased in 2017 (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. Loans in our ending delinquent inventory within the IADAs were 12,446 as of December 31, 2017. The majority of notices of delinquency received from the IADAs due to the hurricane activity cured during 2018. Other items removed from inventory During 2019 , 2018 , and 2017 our losses paid included amounts paid upon commutation of coverage on policies . The impacts of the commutations of coverage on policies and/or settlements in each of the past three years were as follows: • 2019 - 639 notices removed from delinquent inventory with an amount paid of $30 million , • 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 . In 2019 our losses paid included $23.5 million paid in connection with settlements of disputes concerning our claims paying practices. 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 had been delinquent for three months or less (table 8.4 ) as of December 31, 2017. The number of consecutive months that a borrower has been delinquent is shown in table 8.4 below. Primary delinquent inventory - consecutive months delinquent Table 8.4 December 31, 2019 2018 2017 3 months or less 9,447 9,829 17,119 4 - 11 months 9,664 9,655 12,050 12 months or more (1) 10,917 13,414 17,387 Total 30,028 32,898 46,556 3 months or less 32 % 30 % 37 % 4 - 11 months 32 % 29 % 26 % 12 months or more 36 % 41 % 37 % Total 100 % 100 % 100 % Primary claims received inventory included in ending delinquent inventory 538 809 954 (1) Approximately 36% , 38% , and 45% of the delinquent inventory for 12 consecutive months or more has been delinquent for at least 36 consecutive months as of December 31, 2019 , 2018 and 2017 , respectively. POOL INSURANCE DEFAULT INVENTORY Pool insurance default inventory decreased to 653 at December 31, 2019 from 859 at December 31, 2018 and 1,309 at December 31, 2017 . 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, see Note 17 – “Litigation and Contingencies.”

Reinsurance

Reinsurance	12 Months Ended
Reinsurance	Dec. 31, 2019
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) 2019 2018 2017 Premiums earned: Direct $ 1,155,240 $ 1,084,748 $ 1,059,973 Assumed 5,085 1,805 509 Ceded (129,337 ) (111,391 ) (125,735 ) Net premiums earned $ 1,030,988 $ 975,162 $ 934,747 Losses incurred: Direct $ 130,100 $ 43,060 $ 74,727 Assumed (125 ) 331 183 Ceded (11,400 ) (6,829 ) (21,201 ) Net losses incurred $ 118,575 $ 36,562 $ 53,709 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 (or a comparable rating) by Standard and Poor's Rating Services, A.M. Best, Moody's, or a combination of the three. 2019 QSR Transaction. We entered into 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 NIW in 2019. Under the 2019 QSR Transaction, we will cede losses 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 or 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, full financial statement credit or full credit under applicable regulatory capital requirements 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 an annual profit commission provided the annual loss ratio on the loans covered under the transactions remains below 62% . 2018 QSR Transaction. Our 2018 quota share reinsurance agreement ("2018 QSR Transaction") provides coverage on eligible NIW 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, full financial statement credit or full credit under applicable regulatory capital requirements 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 an annual profit commission provided the annual loss ratio on the loans covered under the transactions remains below 62% . 2017 QSR Transaction. Our 2017 quota share reinsurance agreement ("2017 QSR Transaction") provides coverage on eligible NIW 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, full financial statement credit or full credit under applicable regulatory capital requirements for the risk ceded in any required calculation period. The structure of the 2017 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 2017 QSR Transaction, we will receive an annual profit commission provided the annual loss ratio on the loans covered under the transactions remains below 60% . 2015 QSR Transaction . We terminated a portion of our 2015 QSR Transaction effective June 30, 2019 and entered into an amended quota share reinsurance agreement with certain participants from the existing reinsurance panel that effectively reduces the quota share cede rate from 30% to 15% on the remaining eligible insurance. During the second quarter of 2019, we incurred a termination fee of $6.8 million , which was paid to participants of the reinsurance panel that are not participating in the amended 2015 QSR Transaction. Under the amended 2015 QSR Transaction we cede losses and premiums on eligible insurance written before 2017 through December 31, 2031, at which time the agreement expires. Early termination of the amended agreement can be elected by us on or after June 30, 2021, bi-annually thereafter for no fee, or under specified scenarios, including if we will receive less than 90% of the full credit amount under the PMIERs, full financial statement credit or full credit under applicable regulatory capital requirements for the risk ceded in any required calculation period. Generally, under our amended 2015 QSR Transaction, we will receive an annual profit commission provided the annual loss ratio on the loans covered under the transactions remains below 68% . Table 9.2 provides a summary of our quota share reinsurance agreements, excluding captive agreements, for 2019 , 2018 and 2017 . Quota share reinsurance Table 9.2 Years ended December 31, (In thousands) 2019 2018 2017 Ceded premiums written and earned, net of profit commission (1) $ 111,550 $ 108,337 $ 120,974 Ceded losses incurred 11,395 6,543 22,336 Ceding commissions (2) 48,793 51,201 49,321 Profit commission 139,179 147,667 125,629 (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 $21.6 million as of December 31, 2019 and $33.2 million as of December 31, 2018 .The reinsurance recoverable balance is secured by funds on deposit from the reinsurers, the amount of which is based on the funding requirements of PMIERs. 2020 QSR Transaction. We have agreed to terms on a QSR Transaction with a group of unaffiliated reinsurers with an effective date of January 1, 2020 ("2020 QSR Transaction"), which provides coverage on eligible NIW in 2020 Under the 2020 QSR Transaction, we cede losses incurred and premiums on or after the effective date through December 31, 2031, at which time the agreement expires. Early termination of the agreement can be elected by us effective December 31, 2022, 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 2020 QSR Transaction is a 30% quota share on 2020 NIW, with an option to reduce the cede rate to either 25.0% or 20% effective July 1, 2021 or semiannually thereafter. Generally, under the 2020 QSR Transaction, we will receive an annual profit commission provided the annual loss ratio on the loans covered under the transactions remains below 62% . 2021 QSR Transaction. In addition, w e have agreed to terms on a QSR Transaction with a group of unaffiliated reinsurers with an effective date of January 1, 2021 ("2021 QSR Transaction"), which provides coverage on eligible NIW in 2021. Under the 2021 QSR Transaction, we cede losses incurred and premiums on or after the effective date through December 31, 2032 for 2021 NIW, at which time the agreement expires. Early termination of the agreement can be elected by us effective December 31, 2023, 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 2021 QSR Transaction is a 17.5% quota share on 2021 NIW, with an option to reduce the cede rate to either 14.5% or 12% effective July 1, 2022 or semiannually thereafter. Generally, under the 2021 QSR Transaction, we will receive an annual profit commission provided the annual loss ratio on the loans covered under the transactions remains below 62% . EXCESS OF LOSS REINSURANCE We have aggregate excess of loss reinsurance agreements (“Home Re Transactions”) with unaffiliated special purpose insurers domiciled in Bermuda (“Home Re Entities”). For the reinsurance coverage periods, we retain the first layer of the respective aggregate losses, and a Home Re special purpose entity will then provide second layer coverage up to the outstanding reinsurance coverage amount. We retain losses in excess of the outstanding reinsurance coverage amount. The aggregate excess of loss reinsurance coverage decreases over a ten-year period, subject to certain conditions, as the underlying covered mortgages amortize or are repaid, or mortgage insurance losses are paid. MGIC has rights to terminate the Home Re Transactions under certain circumstances. The Home Re entities financed the coverages by issuing mortgage insurance-linked notes (“ILNs”) to unaffiliated investors in an aggregate amount equal to the initial reinsurance coverage amounts. The ILNs each have ten-year legal maturities and are non-recourse to any assets of MGIC or affiliates. The proceeds of the ILNs, which were deposited into reinsurance trusts for the benefit of MGIC, will be the source of reinsurance claim payments to MGIC and principal repayments on the ILNs. Table 9.3 provides a summary of our excess of loss reinsurance agreements as of December 31, 2019 and December 31, 2018. Excess of Loss Reinsurance Table 9.3 (In thousands) As of December 31, 2019 As of December 31, 2018 Home Re Entity (Issue Date) Policy Inforce Dates Termination Option Date (1) Remaining First Layer Retention Remaining Excess of Loss Reinsurance Coverages Remaining First Layer Retention Remaining Excess of Loss Reinsurance Coverages Home Re 2018-1 Ltd. (Oct. - 2018) July 1, 2016 - December 31, 2017 October 25, 2025 $ 167,779 $ 260,957 $ 168,691 $ 318,636 Home Re 2019-1 Ltd. (May - 2019) January 1, 2018 - March 31, 2019 May 25, 2026 185,636 271,021 — — Total $ 353,415 $ 531,978 $ 168,691 $ 318,636 (1) We have the right to terminate the excess-of-loss reinsurance agreements under certain circumstances and on any payment date on or after the respective termination option date. The reinsurance premiums ceded to each Home Re Entity are composed of coverage, initial expense and supplemental premiums. The coverage premiums are generally calculated as the difference between the amount of interest payable by the Home Re Entity on the unpaid portion of the ILNs it issued to raise funds to collateralize its reinsurance obligations to us, and the investment income collected on the collateral assets. The amount of monthly reinsurance coverage premium ceded will fluctuate due to changes in one-month LIBOR, (or the fallback reference rate, as applicable) and changes in money market rates that affect investment income collected on the assets in the reinsurance trust. As a result, we concluded that each reinsurance agreement contains an embedded derivative that is accounted for separately as a freestanding derivative. The fair values of the derivatives at December 31, 2019 , were not material to our consolidated balance sheet, and the change in fair values during the year ended December 31, 2019 were not material to our consolidated statements of operations. Total ceded premiums were $17.6 million and $2.8 million for the years ended December 31, 2019 and December 31, 2018 , respectively. At the time the Home Re Transactions were entered into, we concluded that each Home Re Entity is 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. Given that MGIC (1) does not have the unilateral power to direct the activities that most significantly affect each Home Re Entity’s economic performance and (2) does not have the obligation to absorb losses or the right to receive benefits of each Home Re Entity, consolidation of neither Home Re Entity is 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 statements of operations, as a result of our involvement with the VIEs under our Home Re Transactions. As of December 31, 2019 , and December 31, 2018 , we did not have material exposure to the VIEs as we have no investment in the VIEs and had no reinsurance claim payments due from either VIE under our reinsurance agreements. We are unable to determine the timing or extent of claims from losses that are ceded under the reinsurance agreements. The VIE assets are deposited in reinsurance trusts for the benefit of MGIC that will be the source of reinsurance claim payments to MGIC. The purpose of the reinsurance trusts is to provide security to MGIC for the obligations of the VIEs under the reinsurance agreements. The trustee of the reinsurance trusts, a recognized provider of corporate trust services, has established segregated accounts within the reinsurance trusts for the benefit of MGIC, pursuant to the trust agreements. The trust agreements are governed by, and construed in accordance with, the laws of the State of New York. If the trustee of the reinsurance trusts failed to distribute claim payments to us as provided in the reinsurance trusts, we would incur a loss related to our losses ceded under the reinsurance agreements and deemed unrecoverable. We are also unable to determine the impact such possible failure by the trustee to perform pursuant to the reinsurance trust agreements 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 VIEs. MGIC has certain termination rights under the reinsurance agreements should its claims not be paid. We consider our exposure to loss from our reinsurance agreements with the VIEs to be remote. Table 9.4 presents the total assets of Home Re Entities as of December 31, 2019 and December 31, 2018. Home Re Entities total assets Table 9.4 (In thousands) Home Re Entity Total VIE Assets December 31, 2019 Home Re 2018-01 Ltd. $ 269,451 Home Re 2019-01 Ltd. $ 283,150 December 31, 2018 Home Re 2018-1 Ltd. $ 318,636 The reinsurance trust agreements provide 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 the Home Re Entities 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 (Los

Other Comprehensive Income (Loss)	12 Months Ended
Other Comprehensive Income (Loss)	Dec. 31, 2019
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, 2019 , 2018 and 2017 are included in table 10.1 below. Components of other comprehensive income (loss) Table 10.1 (In thousands) 2019 2018 2017 Net unrealized investment gains (losses) arising during the year $ 220,139 $ (81,834 ) $ 69,052 Income tax (expense) benefit (46,229 ) 17,188 (21,505 ) Net of taxes 173,910 (64,646 ) 47,547 Net changes in benefit plan assets and obligations 29,129 (19,958 ) (8,983 ) Income tax (expense) benefit (6,117 ) 4,191 3,144 Net of taxes 23,012 (15,767 ) (5,839 ) Net changes in unrealized foreign currency translation adjustment — — 45 Income tax benefit (expense) — — (14 ) Net of taxes — — 31 Total other comprehensive income (loss) 249,268 (101,792 ) 60,114 Total income tax (expense) benefit, net (52,346 ) 21,379 (18,375 ) Total other comprehensive income (loss), net of tax $ 196,922 $ (80,413 ) $ 41,739 The pretax and related income tax benefit (expense) components of the amounts reclassified from our accumulated other comprehensive income (loss) ( "AOCI", "AOCL") to our consolidated statements of operations for the years ended December 31, 2019 , 2018 and 2017 are included in table 10.2 below. Reclassifications from Accumulated Other Comprehensive Income (Loss) Table 10.2 (In thousands) 2019 2018 2017 Reclassification adjustment for net realized (losses) gains included in net income (1) $ 3,637 $ (7,037 ) $ (2,580 ) Income tax (expense) benefit (763 ) 1,477 903 Net of taxes 2,874 (5,560 ) (1,677 ) Reclassification adjustment related to benefit plan assets and obligations (2) (8,097 ) (2,232 ) 906 Income tax benefit (expense) 1,701 469 (317 ) Net of taxes (6,396 ) (1,763 ) 589 Total reclassifications (4,460 ) (9,269 ) (1,674 ) Total income tax benefit, net 938 1,946 586 Total reclassifications, net of tax $ (3,522 ) $ (7,323 ) $ (1,088 ) (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. A roll-forward of AOCI (AOCL) for the years ended December 31, 2019 , 2018 , and 2017 , including amounts reclassified from AOCI (AOCL), is included in table 10.3 below. Roll-forward of Accumulated Other Comprehensive Income (Loss) 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, 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 ) Other comprehensive income (loss) before reclassifications 176,784 16,616 — 193,400 Less: Amounts reclassified from AOCL 2,874 (6,396 ) — (3,522 ) Balance, December 31, 2019, net of tax $ 138,521 $ (65,813 ) $ — 72,708

Benefit Plans

Benefit Plans	12 Months Ended
Benefit Plans	Dec. 31, 2019
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, 2019 , 2018 , and 2017 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, 2019 and 2018 . Components of net periodic benefit cost Table 11.1 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2017 12/31/2019 12/31/2018 12/31/2017 1. Company Service Cost $ 8,345 $ 10,530 $ 9,556 $ 1,345 $ 1,160 $ 813 2. Interest Cost 15,705 15,095 15,475 1,130 834 706 3. Expected Return on Assets (19,466 ) (22,250 ) (20,099 ) (5,785 ) (6,359 ) (5,248 ) 4. Other Adjustments — — — — — — Subtotal 4,584 3,375 4,932 (3,310 ) (4,365 ) (3,729 ) 5. Amortization of: a. Net Transition Obligation/(Asset) — — — — — — b. Net Prior Service Cost/(Credit) (281 ) (351 ) (426 ) (34 ) (4,104 ) (6,649 ) c. Net Losses/(Gains) 8,412 6,937 6,169 — (250 ) — Total Amortization 8,131 6,586 5,743 (34 ) (4,354 ) (6,649 ) 6. Net Periodic Benefit Cost 12,715 9,961 10,675 (3,344 ) (8,719 ) (10,378 ) 7. Cost of settlements 1,933 — — — — — 8. Total Expense for Year $ 14,648 $ 9,961 $ 10,675 $ (3,344 ) $ (8,719 ) $ (10,378 ) Development of funded status Table 11.2 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 Actuarial Value of Benefit Obligations 1. Measurement Date 12/31/2019 12/31/2018 12/31/2019 12/31/2018 2. Accumulated Benefit Obligation $ 412,939 $ 375,562 $ 27,496 $ 28,085 Funded Status/Asset (Liability) on the Consolidated Balance Sheet 1. Projected Benefit Obligation $ (413,350 ) $ (376,153 ) $ (27,496 ) $ (28,085 ) 2. Plan Assets at Fair Value 402,691 359,719 99,590 77,762 3. Funded Status - Overfunded/Asset N/A N/A $ 72,094 $ 49,677 4. Funded Status - Underfunded/Liability (10,659 ) (16,434 ) N/A N/A Accumulated other comprehensive (income) loss Table 11.3 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Net Actuarial (Gain)/Loss $ 99,826 $ 110,321 $ (18,005 ) $ 939 2. Net Prior Service Cost/(Credit) (1,237 ) (1,513 ) 2,724 2,690 3. Net Transition Obligation/(Asset) — — — — 4. Total at Year End $ 98,589 $ 108,808 $ (15,281 ) $ 3,629 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 2019 and 2018 . Change in projected benefit / accumulated benefit Table 11.4 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Benefit Obligation at Beginning of Year $ 376,153 $ 417,770 $ 28,085 $ 24,716 2. Company Service Cost 8,345 10,530 1,345 1,160 3. Interest Cost 15,705 15,095 1,130 834 4. Plan Participants' Contributions — — 382 475 5. Net Actuarial (Gain)/Loss due to Assumption Changes 43,302 (36,132 ) (1,215 ) (1,209 ) 6. Net Actuarial (Gain)/Loss due to Plan Experience 3,811 2,487 (860 ) (692 ) 7. Benefit Payments from Fund (1) (30,829 ) (32,674 ) (826 ) (1,077 ) 8. Benefit Payments Directly by Company (3,105 ) (908 ) — — 9. Plan Amendments (5 ) (15 ) — 3,928 10. Other Adjustment — — (545 ) (50 ) 11. Settlement (Gain)/Loss (27 ) — — — 11. Benefit Obligation at End of Year $ 413,350 $ 376,153 $ 27,496 $ 28,085 (1) Includes lump sum payments of $18.5 million and $20.9 million in 2019 and 2018 , respectively, from our pension plan to eligible participants, which were former employees with vested benefits. The increase in our pension and supplemental executive retirement plans obligation in 2019 compared to 2018 was primarily due to a decrease in the discount rate used to calculate the obligation partially offset by benefits paid from the fund. Table 11.8 below includes the actuarial assumptions used to calculate the benefit obligations of our plans for 2019 and 2018 . 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 2019 and 2018 . Change in plan assets Table 11.5 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Fair Value of Plan Assets at Beginning of Year $ 359,719 $ 401,142 $ 77,762 $ 85,303 2. Company Contributions 10,205 10,908 — — 3. Plan Participants' Contributions — — 382 475 4. Benefit Payments from Fund (30,829 ) (32,674 ) (826 ) (1,077 ) 5. Benefit Payments paid directly by Company (3,105 ) (908 ) — — 6. Actual Return on Assets 70,262 (19,583 ) 22,654 (6,464 ) 7. Other Adjustment (3,561 ) 834 (382 ) (475 ) 8. Fair Value of Plan Assets at End of Year $ 402,691 $ 359,719 $ 99,590 $ 77,762 Change in accumulated other comprehensive income (loss) ("AOCI") Table 11.6 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. AOCI in Prior Year $ 108,808 $ 108,054 $ 3,629 $ (15,576 ) 2. Increase/(Decrease) in AOCI a. Recognized during year - Prior Service (Cost)/Credit 281 351 34 4,104 b. Recognized during year - Net Actuarial (Losses)/Gains (8,412 ) (6,937 ) — 250 c. Occurring during year - Prior Service Cost (5 ) (15 ) — 3,928 d. Occurring during year - Net Actuarial Losses/(Gains) (150 ) 7,355 (18,944 ) 10,923 e. Occurring during year - Net Settlement Losses/(Gains) (1,933 ) — — — 3. AOCI in Current Year $ 98,589 $ 108,808 $ (15,281 ) $ 3,629 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, 2020 . Amortization expected to be recognized during fiscal year ending Table 11.7 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2019 1. Amortization of Net Transition Obligation/(Asset) $ — $ — 2. Amortization of Prior Service Cost/(Credit) (248 ) 51 3. Amortization of Net Losses/(Gains) 6,534 (761 ) 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 12/31/2019 12/31/2018 12/31/2019 12/31/2018 Weighted-Average Assumptions Used to Determine Benefit Obligations at year end 1. Discount Rate 3.45 % 4.40 % 3.20 % 4.25 % 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 4.40 % 3.75 % 4.25 % 3.55 % 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 6.00 % 6.25 % 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 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Equity Securities 23 % 23 % 100 % 100 % 2. Debt Securities 77 % 77 % — % — % 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, 2019 and 2018 . There were no securities that used Level 3 inputs. Pension plan assets at fair value as of December 31, 2019 Table 11.10a (In thousands) Level 1 Level 2 Total Domestic Mutual Funds $ 7,325 $ — $ 7,325 Corporate Bonds — 203,684 203,684 U.S. Government Securities 32,166 2,511 34,677 Municipal Bonds — 38,998 38,998 Foreign Bonds — 34,024 34,024 ETFs — — — Pooled Equity Accounts — 83,983 83,983 Total Assets at fair value $ 39,491 $ 363,200 $ 402,691 Pension plan assets at fair value as of December 31, 2018 Table 11.10b (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 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 ● Global low volatility Return seeking bridge Downside protection in the event of a declining equity market ● Enduring asset ● 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, 2019 and 2018 . All are Level 1 assets. Other postretirement benefits plan assets at fair value as of December 31, 2019 Table 11.11a (In thousands) Level 1 Total Domestic Mutual Funds $ 77,640 $ 77,640 International Mutual Funds 21,950 21,950 Total Assets at fair value $ 99,590 $ 99,590 Other postretirement benefits plan assets at fair value as of December 31, 2018 Table 11.11b (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 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, 2019 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) 12/31/2019 12/31/2019 Company Contributions for the Year Ending: 1. Current $ 10,205 $ — 2. Current + 1 12,350 — Benefits payments - total Table 11.13 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2019 Actual Benefit Payments for the Year Ending: 1. Current $ 33,934 $ 989 Expected Benefit Payments for the Year Ending: 2. Current + 1 34,943 1,600 3. Current + 2 31,008 1,847 4. Current + 3 30,981 2,087 5. Current + 4 31,175 2,254 6. Current + 5 30,547 2,367 7. Current + 6 - 10 141,768 11,874 HEALTH CARE SENSITIVITIES Assumed health care cost trend rates have a significant effect on the amounts reported for the other postretirement benefits plan. A one 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 $ 380 $ (328 ) Effect on postretirement benefit obligation 2,528 (2,239 ) 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 of 100% up to the first 4% contributed. We recognized expenses related to these plans of $7.4 million , $6.0 million and $6.0 million in 2019 , 2018 and 2017

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 12 Income Taxes Net deferred tax assets and liabilities as of December 31, 2019 and 2018 are as follows: Deferred tax assets and liabilities Table 12.1 (In thousands) 2019 2018 Total deferred tax assets $ 63,533 $ 83,082 Total deferred tax liabilities (57,791 ) (13,898 ) Net deferred tax asset $ 5,742 $ 69,184 Table 12.2 includes the components of the net deferred tax asset as of December 31, 2019 and 2018 . Deferred tax components Table 12.2 (In thousands) 2019 2018 Unearned premium reserves $ 30,487 $ 31,808 Benefit plans (10,790 ) (5,047 ) Loss reserves 2,175 3,113 Unrealized (appreciation) depreciation in investments (36,822 ) 9,407 Mortgage investments 8,359 8,307 Deferred compensation 9,270 8,662 AMT credit carryforward 8,303 17,521 Other, net (5,240 ) (4,587 ) Net deferred tax asset $ 5,742 $ 69,184 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 and 2019 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) 2019 2018 2017 Current Federal $ 162,911 $ (16,272 ) $ 73,348 Deferred Federal 11,860 185,598 351,677 Other (557 ) 4,727 3,710 Provision for income taxes $ 174,214 $ 174,053 $ 428,735 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 $158.3 million , $12.2 million , and $22.0 million in 2019 , 2018 and 2017 , respectively. At December 31, 2019 we owned $176.0 million of tax and loss bonds. Table 12.6 reconciles the federal statutory income tax rate to our effective tax provision rate. Effective tax rate reconciliation Table 12.6 2019 2018 2017 Federal statutory income tax rate 21.0 % 21.0 % 35.0 % Additional income tax provision (benefit) related to the rate decrease included in the Tax Act — % — % 17.0 % Additional income tax provision (benefit) related to IRS litigation — % (0.3 )% 3.7 % Tax exempt municipal bond interest (0.6 )% (0.7 )% (1.4 )% Other, net 0.1 % 0.6 % 0.4 % Effective tax rate 20.5 % 20.6 % 54.7 % 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 2018, we finalized an agreement with the IRS to settle all issues in the examinations and related U.S. Tax Court case. 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 Balance at beginning of year $ 142,821 $ 108,245 Additions for tax positions of prior years — 35,003 Reductions for tax positions of prior years (3,070 ) (427 ) Settlements (139,751 ) — Balance at end of year $ — $ 142,821 We have no unrecognized tax benefits at December 31, 2018 and December 31, 2019. We have not recorded any uncertain tax positions during 2019. We recognize interest accrued and penalties related to unrecognized tax benefits in income taxes. The statute of limitations related to the consolidated federal income tax return is closed for all years prior to 2015.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
Shareholders' Equity	Dec. 31, 2019
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 During 2019 we repurchased approximately 8.7 million shares of our common stock at a weighted average cost per share of $13.13 , which included commissions. We may repurchase an additional $111 million of our common stock through the end of 2020 under share repurchase programs approved by our Board of Directors in 2019. We received authorization in the first quarter of 2020 to repurchase an additional $300 million of our common stock through the end of 2021. 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. Repurchases may be made from time to time on the open market (including through 10b5-1 plans) or through privately negotiated transactions. The repurchase program may be suspended for periods or discontinued at any time. Cash dividends In September 2019 and November 2019, we paid a quarterly cash dividend of $0.06 per share to shareholders which totaled $42 million . On January 28, 2020, the Board of Directors declared a quarterly cash dividend to holders of the company's common stock of $0.06 per share payable on February 28, 2020, to shareholders of record at the close of business on February 11, 2020. 2017 CAPITAL TRANSACTIONS 2% Notes In 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.

Statutory Information

Statutory Information	12 Months Ended
Statutory Information	Dec. 31, 2019
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 2019 , MGIC's losses incurred were 12% 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. As a mortgage guaranty insurer, we are eligible for a tax deduction, subject to certain limitations, under Section 832(e) of the IRC for amounts required by state law or regulation to be set aside in statutory contingency reserves. The deduction is allowed only to the extent that we purchase tax and loss bonds (“T&L Bonds”) in an amount equal to the tax benefit derived from deducting any portion of our statutory contingency reserves. Under statutory accounting practices, purchases of T&L Bonds are accounted for as investments. Under GAAP, purchases of T&L Bonds are accounted for as a payment of current taxes. 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) 2019 2018 2017 Statutory net income $ 305,857 $ 375,484 $ 310,776 Statutory policyholders' surplus 1,619,069 1,683,058 1,622,115 Contingency reserve 3,021,055 2,442,996 1,896,701 For the years ended December 31, 2019 , 2018 , and 2017 there were no surplus contributions made to MGIC or distributions from other insurance subsidiaries to us. Dividends paid by MGIC are shown in table 14.2 below. Surplus contributions and dividends of insurance subsidiaries Table 14.2 Years Ended December 31, (In thousands) 2019 2018 2017 Dividends paid by MGIC to the parent company $ 280,000 220,000 140,000 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, 2019 , MGIC’s risk-to-capital ratio was 9.7 to 1 , below the maximum allowed by the jurisdictions with State Capital Requirements and its policyholder position was $3.0 billion above the required MPP of $1.7 billion . The calculation of our risk-to-capital ratio and MPP reflect credit for the risk ceded under our QSR Transactions and Home Re Transactions with a group of 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 agreements, 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, 2019 , the risk-to-capital ratio of our combined insurance operations (which includes a reinsurance affiliate) was 9.6 to 1 . In the first quarter of 2020, we received the appropriate approvals for MGIC to pay our holding company a special dividend of $320 million . The $320 million special dividend will reduce the statutory policyholder's position of MGIC, which will result in an increase to the risk-to-capital. The NAIC has previously announced plans to revise the minimum capital and surplus requirements for mortgage insurers that are provided for in its Mortgage Guaranty Insurance Model Act. In December 2019, a working group of state regulators released an exposure draft of a revised Mortgage Guaranty Insurance Model Act and 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 and minimum capital floors. Currently we believe that the PMIERs contain 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 2019 , MGIC paid a total of $280 million in dividends to our holding company. We received the appropriate approvals for MGIC to pay our holding company, in the first quarter of 2020, a special dividend of $320 million and a quarterly dividend of $70 million . We expect MGIC to continue to pay dividends of at least $280 million per year. 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. Before making any dividend payments in 2020, we will notify the OCI to ensure it does not object. 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, 2019 , MGIC’s increase in contingency reserves was $556 million and statutory net income was $273 million . As of December 31, 2019 , MGIC's statutory policyholders' surplus was $1,619 million .

Share-based Compensation Plans

Share-based Compensation Plans	12 Months Ended
Share-based Compensation Plans	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Share-based Compensation Plans	NOTE 15 Share-based Compensation Plans 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 . We have an omnibus incentive plan that was adopted on April 23, 2015. The purpose of the 2015 plan is to motivate and incentive 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, 2019 , 3.4 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 $18.9 million , $20.9 million , and $14.9 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. The related income tax benefit recognized for share-based plans was $2.7 million , $3.0 million , and $5.2 million for the years ended December 31, 2019 , 2018 , and 2017 , respectively. Table 15.1 summarizes restricted stock or restricted stock unit (collectively called “restricted stock”) activity during 2019 . Restricted stock Table 15.1 Weighted Average Grant Date Fair Market Value Shares Restricted stock outstanding at December 31, 2018 $ 12.27 3,583,506 Granted 11.92 2,002,500 Vested 9.37 (1,067,890 ) Forfeited 13.67 (367,722 ) Restricted stock outstanding at December 31, 2019 $ 12.81 4,150,394 At December 31, 2019 , the 4.2 million shares of restricted stock outstanding consisted of 3.2 million shares that are subject to performance conditions (“performance shares”) and 1.0 million shares that are subject only to service conditions (“time vested shares”). The weighted-average grant date fair value of restricted stock granted during 2018 and 2017 was $15.69 and $10.41 , 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 or previous trading day if the Exchange is closed on the date of grant. The total fair value of restricted stock vested during 2019 , 2018 and 2017 was $13.7 million , $19.1 million , and $15.3 million , respectively. As of December 31, 2019 , there was $30.7 million of total unrecognized compensation cost related to non-vested share-based compensation agreements granted under the plans. Of this total, $20.2 million of unrecognized compensation costs relate to performance shares and $10.5 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

Leases	12 Months Ended
Leases	Dec. 31, 2019
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, 2019 . Minimum future operating lease payments Table 16.1 (In thousands) Amount 2020 $ 1,204 2021 588 2022 380 2023 83 2024 and thereafter — Total $ 2,255 Table 16.2 shows minimum the future operating lease payments as of December 31, 2018. Minimum future operating lease payments Table 16.2 (In thousands) Amount 2019 $ 1,406 2020 1,069 2021 371 2022 161 2023 and thereafter — Total $ 3,007 Total lease expense under operating leases was $2.1 million in 2019 , $1.9 million in 2018 , and $2.0 million in 2017 .

Litigation and Contingencies

Litigation and Contingencies	12 Months Ended
Litigation and Contingencies	Dec. 31, 2019
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 2019 and 2018 , curtailments reduced our average claim paid by approximately 5.0% 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 loss 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. When we determine that a loss is probable and can be reasonably estimated, we record our best estimate of our probable loss. In those cases, until settlement negotiations or legal proceedings are concluded (including the receipt of any necessary GSE approvals), it is reasonably possible that we will record an additional loss. In the fourth quarter of 2019, the agreement for which we had recorded a probable loss of $23.5 million , received necessary GSE approvals. There was no additional loss recognized as a result of entering into the agreement, as the settlement amount was consistent with our original estimate of the probable loss. We are currently involved in discussions and/or proceedings with insureds with respect to our claims paying practices. Although it is reasonably possible that when all of 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 $46 million . This estimate of maximum exposure is based upon currently available information; is subject to significant judgment, numerous assumptions and known and unknown uncertainties; will include an amount for matters for which we have recorded a probable loss until such matters are concluded; will include different matters from time to time; and does not include interest or consequential or exemplary damages. Mortgage insurers, including MGIC, have in the past been involved in litigation and regulatory actions related to alleged violations of the anti-referral fee provisions of the Real Estate Settlement Procedures Act ("RESPA") and the notice provisions of the Fair Credit Reporting Act ("FCRA"). While these proceedings in the aggregate did not result 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. To the extent that we are construed to make independent credit decisions in connection with our contract underwriting activities, we also could be subject to increased regulatory requirements under the Equal Credit Opportunity Act (“EOCA”), FCRA, and other laws. Under ECOA, examination may also be made of whether a mortgage insurer’s underwriting decisions have a disparate impact on persons belonging to a protected class in violation of the law. 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, 2019 , 2018 , and 2017 , 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 D

Unaudited Quarterly Financial Data	12 Months Ended
Unaudited Quarterly Financial Data	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Financial Data	NOTE 18 Unaudited Quarterly Financial Data Unaudited quarterly financial data - current year: Table: 18.1a 2019: Quarter Full (In thousands, except per share data) First Second Third Fourth Year Net premiums earned $ 249,762 $ 247,102 $ 267,857 $ 266,267 $ 1,030,988 Investment income, net of expenses 40,585 42,423 42,715 41,322 167,045 Realized (losses) gains (526 ) 307 4,205 1,320 5,306 Other revenue 1,830 2,485 3,606 2,717 10,638 Loss incurred, net 39,064 21,836 33,985 23,690 118,575 Underwriting and other expenses, net 61,650 59,270 61,278 65,227 247,425 Provision for income tax 38,996 43,433 46,186 45,599 174,214 Net income 151,941 167,778 176,934 177,110 673,763 Income per share (a) (b) : Basic 0.43 0.47 0.50 0.51 1.91 Diluted 0.42 0.46 0.49 0.49 1.85 Unaudited quarterly financial statements - prior year: Table: 18.1b 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 gains (losses) (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 (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 INVESTM

SCHEDULE I - SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-15, Insurance Companies, 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, 2019 (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 $ 195,176 $ 196,203 $ 196,203 States, municipalities and political subdivisions 1,555,394 1,653,865 1,653,865 Public utilities 270,675 278,991 278,991 Asset-backed securities 227,376 229,664 229,664 Collateralized loan obligations 327,076 325,466 325,466 Mortgage-backed 545,618 547,572 547,572 All other corporate bonds 2,441,235 2,506,131 2,506,131 Total fixed income 5,562,550 5,737,892 5,737,892 Equity securities: Common stocks: Industrial, miscellaneous and all other 17,188 17,328 17,328 Total equity securities 17,188 17,328 17,328 Total investments $ 5,579,738 $ 5,755,220 $ 5,755,220

SCHEDULE II - CONDENSED FINANCI

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT	12 Months Ended
SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT	Dec. 31, 2019
Condensed Financial Information 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) 2019 2018 ASSETS Fixed income, available-for-sale, at fair value (amortized cost, 2019 – $287,489; 2018 – $203,743) $ 288,362 $ 201,507 Cash and cash equivalents 36,621 46,502 Investment in subsidiaries, at equity in net assets 4,611,356 3,981,970 Accounts receivable - affiliates 2,129 1,396 Income taxes - current and deferred 196,978 186,561 Accrued investment income 2,498 2,020 Other assets 81 740 Total assets $ 5,138,025 $ 4,420,696 LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities: Senior notes $ 420,867 $ 419,713 Convertible junior subordinated debentures 389,522 389,522 Accrued interest 17,928 17,930 Other liabilities 474 11,640 Total liabilities 828,791 838,805 Shareholders’ equity: Common stock, (one dollar par value, shares authorized 1,000,000; shares issued 2019 – 371,353; 2018 – 371,353; outstanding 2019 – 347,308; 2018 – 355,371) 371,353 371,353 Paid-in capital 1,869,719 1,862,536 Treasury stock (shares at cost 2019 – 24,045; 2018 – 15,982) (283,196 ) (175,059 ) Accumulated other comprehensive income (loss), net of tax 72,708 (124,214 ) Retained earnings 2,278,650 1,647,275 Total shareholders’ equity 4,309,234 3,581,891 Total liabilities and shareholders’ equity $ 5,138,025 $ 4,420,696 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) 2019 2018 2017 Revenues: Investment income, net of expenses $ 7,695 $ 4,685 $ 3,177 Net realized investment (losses) gains (311 ) (532 ) (13 ) Total revenues 7,384 4,153 3,164 Expenses: Operating expenses 793 637 642 Interest expense 61,593 61,930 65,972 Loss on debt extinguishment — — 65 Total expenses 62,386 62,567 66,679 Loss before tax (55,002 ) (58,414 ) (63,515 ) (Benefit from) provision for income taxes (12,263 ) (13,517 ) 95,517 Equity in net income of subsidiaries 716,502 714,994 514,793 Net income 673,763 670,097 355,761 Other comprehensive income (loss), net of tax 196,922 (80,413 ) 41,739 Comprehensive income $ 870,685 $ 589,684 $ 397,500 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) 2019 2018 2017 Cash flows from operating activities: Net income $ 673,763 $ 670,097 $ 355,761 Adjustments to reconcile net income to net cash provided by operating activities: Equity in net income of subsidiaries (716,502 ) (714,994 ) (514,793 ) Dividends received from subsidiaries 154,413 199,692 110,145 Deferred tax (benefit) expense (10,416 ) (11,756 ) 96,741 Loss on debt extinguishment — — 65 Other 21,104 24,303 18,716 Change in certain assets and liabilities: Accounts receivable - affiliates (735 ) 18 (634 ) Income taxes receivable 1 17,859 297 Accrued investment income (478 ) 112 (192 ) Accrued interest (2 ) (4 ) (2,819 ) Net cash provided by operating activities 121,148 185,327 63,287 Cash flows from investing activities: Purchases of investments (117,663 ) (83,003 ) (97,091 ) Proceeds from sales of investments 160,040 93,481 176,960 Net cash provided by investing activities 42,377 10,478 79,869 Cash flows from financing activities: Proceeds from revolving credit facility — — 150,000 Repayment of revolving credit facility — — (150,000 ) Repurchase of convertible senior notes — — (150,124 ) Repurchase of common stock (125,766 ) (163,419 ) — Dividends paid (41,914 ) — — Payment of debt issuance costs — — (1,630 ) Payment of withholding taxes related to share-based compensation net share settlement (5,726 ) (8,131 ) (6,821 ) Net cash used in financing activities (173,406 ) (171,550 ) (158,575 ) Net (decrease) increase in cash and cash equivalents (9,881 ) 24,255 (15,419 ) Cash and cash equivalents at beginning of year 46,502 22,247 37,666 Cash and cash equivalents at end of year $ 36,621 $ 46,502 $ 22,247 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 paid a total of $280 million , $220 million and $140 million in dividends in cash and fixed income securities to our holding company during 2019, 2018 and 2017, respectively. In January 2020, we received the appropriate approvals for MGIC to pay our holding company, in the first quarter of 2020, a special dividend of $320 million and a quarterly dividend of $70 million . We expect MGIC to continue to pay quarterly dividends totaling at least $280 million per year. No contributions were made to our insurance subsidiaries in 2019, 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%

SCHEDULE IV - REINSURANCE

SCHEDULE IV - REINSURANCE	12 Months Ended
SCHEDULE IV - REINSURANCE	Dec. 31, 2019
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
SCHEDULE IV - REINSURANCE	SCHEDULE IV — Reinsurance Mortgage Insurance Premiums Earned Years Ended December 31, 2019, 2018 and 2017 (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, 2019 $ 1,155,240 $ 129,337 $ 5,085 $ 1,030,988 0.5 % 2018 1,084,748 111,391 1,805 975,162 0.2 % 2017 1,059,973 125,735 509 934,747 0.1 %

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2019
Accounting Policies [Abstract]
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 2018 and 2017 amounts have been made in the accompanying consolidated financial statements to conform to the 2019
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 and cash equivalents. 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. 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. Equity securities are reported at fair value, except for certain securities that are carried at cost. Equity securities carried at cost are reported as Other invested assets. Effective January 1, 2018, realized investment gains and losses, after considering the related tax expense or benefit, are accounted for as a function of the periodic change in fair value. For 2017, realized investment gains and losses were accounted for as 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.
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 and loss adjustment expenses ("LAE") reserves are established when we receive notices of delinquency on insured mortgage loans. We consider a loan delinquent 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 case reserves for future claims on insured loans which are not currently delinquent. Case 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 case reserve estimates are established based upon historical experience, including 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. Incurred but not reported ("IBNR") 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. IBNR reserves are also established using estimated claim rates and claim severities. LAE reserves are established for the estimated costs of settling claims, including legal and other expenses and general expenses of administering the claims settlement process.
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 re-underwrite 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 estimated 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. The first step applies a more-likely-than-not threshold for recognition and derecognition. The second step measures the tax position as the greatest amount of benefit that is cumulatively greater than 50% likely to be 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.
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
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.
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
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. 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, we had other convertible notes in 2017 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.
Recent accounting and reporting developments	Table 3.1 shows the relevant new amendments to accounting standards, which are not yet effective or adopted. Standard / Interpretation Table 3.1 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 ASC 740 Income Taxes • ASU 2019-12 - Simplifying the Accounting for Income Taxes 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. We have concluded that our mortgage insurance policies are outside the scope of this ASU, however, the provisions of this guidance do apply to our reinsurance transactions, which are highly rated, as discussed in Note 9 – “Reinsurance” to our consolidated financial statements. Entities are required to incorporate 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. The allowance for current expected credit losses (“CECL”) generally reduces the amortized cost basis of the financial instrument to the amount an entity expects to collect, however, credit losses relating to available-for-sale fixed maturity securities are to be recorded through an allowance for credit losses, 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. In May 2019, the FASB amended this guidance to provide entities with an option to irrevocably elect the fair value option for eligible instruments in order to provide targeted transition relief that is intended to increase comparability of financial statement information for some entities that otherwise would have measured similar financial instruments using different measurement methodologies. We have evaluated the impacts the adoption of this guidance will have on our consolidated financial statements, and determined it will not have a material impact. 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 requires 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. We have evaluated the impacts the adoption of this guidance will have on our consolidated financial statements, and determined it will not 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 disclosure requirements 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. Simplifying the Accounting for Income Taxes

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
Significant Accounting Policies (Tables)	Dec. 31, 2019
Accounting Policies [Abstract]
Schedule of Recent Accounting and Reporting Developments	Table 3.1 shows the relevant new amendments to accounting standards, which are not yet effective or adopted. Standard / Interpretation Table 3.1 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 ASC 740 Income Taxes • ASU 2019-12 - Simplifying the Accounting for Income Taxes January 1, 2021

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
Earnings per Share (Tables)	Dec. 31, 2019
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) 2019 2018 2017 Basic earnings per share: Net income $ 673,763 $ 670,097 $ 355,761 Weighted average common shares outstanding - basic 352,827 365,406 362,380 Basic earnings per share $ 1.91 $ 1.83 $ 0.98 Diluted earnings per share: Net income $ 673,763 $ 670,097 $ 355,761 Interest expense, net of tax (1) : 2% Notes — — 907 5% Notes — — 1,709 9% Debentures 18,264 18,264 15,027 Diluted income available to common shareholders $ 692,027 $ 688,361 $ 373,404 Weighted-average shares - basic 352,827 365,406 362,380 Effect of dilutive securities: Unvested restricted stock units 2,069 1,644 1,493 2% Notes — — 8,317 5% Notes — — 3,548 9% Debentures 19,028 19,028 19,028 Weighted average common shares outstanding - diluted 373,924 386,078 394,766 Diluted income per share $ 1.85 $ 1.78 $ 0.95 (1) Interest expense for the years ended December 31, 2019 , 2018 and 2017 has been tax effected at a rate of 21% , 21% , and 35% , respectively.

Investments (Tables)

Investments (Tables)	12 Months Ended
Investments (Tables)	Dec. 31, 2019
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, 2019 and 2018 are shown below: Details of fixed income investment securities by category as of December 31, 2019 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 $ 195,176 $ 1,237 $ (210 ) $ 196,203 Obligations of U.S. states and political subdivisions 1,555,394 99,328 (857 ) 1,653,865 Corporate debt securities 2,711,910 76,220 (3,008 ) 2,785,122 ABS 227,376 2,466 (178 ) 229,664 RMBS 271,384 429 (3,227 ) 268,586 CMBS 274,234 5,531 (779 ) 278,986 CLOs 327,076 33 (1,643 ) 325,466 Total fixed income securities $ 5,562,550 $ 185,244 $ (9,902 ) $ 5,737,892 Details of fixed income investment securities by category as of December 31, 2018 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 $ 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 (1) There were no OTTI losses recorded in other comprehensive (loss) income as of December 31, 2019 and 2018 .
Amortized cost and fair values of debt securities by contractual maturity	Table 5.2 compares the amortized cost and fair values of fixed income securities, by contractual maturity, as of December 31, 2019 . 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, 2019 (In thousands) Amortized Cost Fair Value Due in one year or less $ 425,739 $ 427,616 Due after one year through five years 1,911,433 1,952,278 Due after five years through ten years 1,031,056 1,088,012 Due after ten years 1,094,252 1,167,284 4,462,480 4,635,190 ABS 227,376 229,664 RMBS 271,384 268,586 CMBS 274,234 278,986 CLOs 327,076 325,466 Total as of December 31, 2019 $ 5,562,550 $ 5,737,892
Cost and fair value of investments in equity securities	The cost and fair value of investments in equity securities as of December 31, 2019 and December 31, 2018 are shown in tables 5.3a and 5.3b below. 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. Details of equity investment securities as of December 31, 2019 Table 5.3a (In thousands) Cost Gross gains Gross losses Fair Value Equity securities 17,188 154 (14 ) 17,328 Details of equity investment securities as of December 31, 2018 Table 5.3b (In thousands) Cost Gross gains Gross losses Fair Value Equity securities 3,993 11 (72 ) 3,932
Aging of the fair values of securities in an unrealized loss position	Tables 5.4a and 5.4b below summarize, for all available-for-sale investments in an unrealized loss position as of December 31, 2019 and 2018 , 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 $10 million and $78 million as of December 31, 2019 and 2018 , 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, 2019 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 $ 57,301 $ (200 ) $ 5,806 $ (10 ) $ 63,107 $ (210 ) Obligations of U.S. states and political subdivisions 74,859 (847 ) 6,957 (10 ) 81,816 (857 ) Corporate debt securities 221,357 (2,847 ) 43,505 (161 ) 264,862 (3,008 ) ABS 21,542 (118 ) 3,851 (60 ) 25,393 (178 ) RMBS 105,443 (461 ) 110,452 (2,766 ) 215,895 (3,227 ) CMBS 62,388 (728 ) 11,852 (51 ) 74,240 (779 ) CLOs 81,444 (225 ) 196,988 (1,418 ) 278,432 (1,643 ) Total $ 624,334 $ (5,426 ) $ 379,411 $ (4,476 ) $ 1,003,745 $ (9,902 ) Unrealized loss aging for securities by type and length of time as of December 31, 2018 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 $ 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 )
Net investment income	The source of net investment income is shown in table 5.5 below. Net investment income Table 5.5 (In thousands) 2019 2018 2017 Fixed income securities $ 165,523 $ 140,539 $ 122,105 Equity securities 406 228 206 Cash equivalents 4,444 3,423 1,447 Other 974 816 620 Investment income 171,347 145,006 124,378 Investment expenses (4,302 ) (3,675 ) (3,507 ) Net investment income $ 167,045 $ 141,331 $ 120,871
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) 2019 2018 2017 Fixed income securities $ 220,139 $ (81,834 ) $ 69,026 Equity securities — — 39 Other — — (13 ) Change in unrealized gains/losses $ 220,139 $ (81,834 ) $ 69,052

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2019
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, 2019 and 2018 : Assets carried at fair value by hierarchy level as of December 31, 2019 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 $ 196,203 $ 34,240 $ 161,963 $ — Obligations of U.S. states and political subdivisions 1,653,865 — 1,653,865 — Corporate debt securities 2,785,122 — 2,785,122 — ABS 229,664 — 229,664 — RMBS 268,586 — 268,586 — CMBS 278,986 — 278,986 — CLOs 325,466 — 325,466 — Total fixed income securities 5,737,892 34,240 5,703,652 — Equity securities 17,328 17,328 — — Other (1) 164,693 164,693 — — Real estate acquired (2) 7,252 — — 7,252 Total $ 5,927,165 $ 216,261 $ 5,703,652 $ 7,252 Assets carried at fair value by hierarchy level as of December 31, 2018 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 $ 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) 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 (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) 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)	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, 2019 , 2018 , and 2017 is shown in tables 6.2a , 6.2b and 6.2c below. 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 6.2b 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, 2019 and 2017. There were no losses included in earnings for the years ended December 31, 2019 , 2018 , and 2017 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, 2019 Table 6.2a (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2018 $ 13 $ — $ 13 $ 14,535 Total realized/unrealized gains (losses): Included in earnings and reported as losses incurred, net — — — (476 ) Acquisitions — — — 24,204 Sales (13 ) — (13 ) (31,011 ) Balance at December 31, 2019 $ — $ — $ — $ 7,252 Fair value roll-forward for financial instruments classified as Level 3 for the year ended December 31, 2018 Table 6.2b (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2017 $ 271 $ 4,268 $ 4,539 $ 12,713 Reclassification for adoption of new accounting standard — (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 ) Acquisitions — — — 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 6.2c (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 ) Acquisitions — — — 34,749 Sales (420 ) — (420 ) (32,469 ) Balance at December 31, 2017 $ 271 $ 4,268 $ 4,539 $ 12,713
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, 2019 and 2018 . Financial liabilities not carried at fair value Table 6.3 December 31, 2019 December 31, 2018 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Financial assets Other invested assets $ 3,100 $ 3,100 $ 3,100 $ 3,100 Financial liabilities FHLB Advance $ 155,000 $ 156,422 $ 155,000 $ 150,551 5.75% Notes 420,867 471,827 419,713 425,791 9% Debentures 256,872 346,289 256,872 338,069 Total financial liabilities $ 832,739 $ 974,538 $ 831,585 $ 914,411

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of debt	Table 7.1 shows the carrying value of our long-term debt obligations as of December 31, 2019 and 2018 . Long-term debt obligations Table 7.1 December 31, (In millions) 2019 2018 FHLB Advance - 1.91%, due February 2023 $ 155.0 $ 155.0 5.75% Notes, due August 2023 (par value: $425 million) 420.9 419.7 9% Debentures, due April 2063 256.9 256.9 Long-term debt, carrying value $ 832.7 $ 831.6

Loss Reserves (Tables)

Loss Reserves (Tables)	12 Months Ended
Loss Reserves (Tables)	Dec. 31, 2019
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 loss reserves Table 8.1 (In thousands) 2019 2018 2017 Reserve at beginning of year $ 674,019 $ 985,635 $ 1,438,813 Less reinsurance recoverable 33,328 48,474 50,493 Net reserve at beginning of year 640,691 937,161 1,388,320 Losses incurred: Losses and LAE incurred in respect of delinquent notices received in: Current year 189,581 203,928 284,913 Prior years (1) (71,006 ) (167,366 ) (231,204 ) Total losses incurred 118,575 36,562 53,709 Losses paid: Losses and LAE paid in respect of delinquent notices received in: Current year 4,018 7,298 11,267 Prior years 235,551 327,743 493,300 Reinsurance terminations (13,996 ) (2,009 ) 301 Total losses paid 225,573 333,032 504,868 Net reserve at end of year 533,693 640,691 937,161 Plus reinsurance recoverables 21,641 33,328 48,474 Reserve at end of year $ 555,334 $ 674,019 $ 985,635 (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 2019 , 2018 and 2017 for previously received delinquencies. Reserve development on previously received delinquencies Table 8.2 (In millions) 2019 2018 2017 Decrease in estimated claim rate on primary delinquencies $ (112 ) $ (213 ) $ (248 ) (Decrease) increase in estimated severity on primary delinquencies (1 ) 29 9 Change in estimates related to pool reserves, LAE reserves, reinsurance and other 42 17 8 Total prior year loss development (1) $ (71 ) $ (167 ) $ (231 ) (1) A negative number for prior year loss development indicates a redundancy of prior year loss reserves.
Rollforward of delinquent inventory roll-forward	A roll-forward of our primary delinquent inventory for the years ended December 31, 2019 , 2018 , and 2017 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 2019 2018 2017 Beginning delinquent inventory 32,898 46,556 50,282 New Notices 54,239 54,448 68,268 Cures (52,035 ) (60,511 ) (61,094 ) Paid claims (4,267 ) (5,750 ) (9,206 ) Rescissions and denials (168 ) (267 ) (357 ) Other items removed from inventory (639 ) (1,578 ) (1,337 ) Ending delinquent inventory 30,028 32,898 46,556
Aging of the primary default inventory	The number of consecutive months that a borrower has been delinquent is shown in table 8.4 below. Primary delinquent inventory - consecutive months delinquent Table 8.4 December 31, 2019 2018 2017 3 months or less 9,447 9,829 17,119 4 - 11 months 9,664 9,655 12,050 12 months or more (1) 10,917 13,414 17,387 Total 30,028 32,898 46,556 3 months or less 32 % 30 % 37 % 4 - 11 months 32 % 29 % 26 % 12 months or more 36 % 41 % 37 % Total 100 % 100 % 100 % Primary claims received inventory included in ending delinquent inventory 538 809 954 (1) Approximately 36% , 38% , and 45% of the delinquent inventory for 12 consecutive months or more has been delinquent for at least 36 consecutive months as of December 31, 2019 , 2018 and 2017 , respectively.

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
Reinsurance (Tables)	Dec. 31, 2019
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) 2019 2018 2017 Premiums earned: Direct $ 1,155,240 $ 1,084,748 $ 1,059,973 Assumed 5,085 1,805 509 Ceded (129,337 ) (111,391 ) (125,735 ) Net premiums earned $ 1,030,988 $ 975,162 $ 934,747 Losses incurred: Direct $ 130,100 $ 43,060 $ 74,727 Assumed (125 ) 331 183 Ceded (11,400 ) (6,829 ) (21,201 ) Net losses incurred $ 118,575 $ 36,562 $ 53,709
Quota share reinsurance, excluding captive agreements	Table 9.2 provides a summary of our quota share reinsurance agreements, excluding captive agreements, for 2019 , 2018 and 2017 . Quota share reinsurance Table 9.2 Years ended December 31, (In thousands) 2019 2018 2017 Ceded premiums written and earned, net of profit commission (1) $ 111,550 $ 108,337 $ 120,974 Ceded losses incurred 11,395 6,543 22,336 Ceding commissions (2) 48,793 51,201 49,321 Profit commission 139,179 147,667 125,629 (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.
Reinsurance retention policy	Table 9.3 provides a summary of our excess of loss reinsurance agreements as of December 31, 2019 and December 31, 2018. Excess of Loss Reinsurance Table 9.3 (In thousands) As of December 31, 2019 As of December 31, 2018 Home Re Entity (Issue Date) Policy Inforce Dates Termination Option Date (1) Remaining First Layer Retention Remaining Excess of Loss Reinsurance Coverages Remaining First Layer Retention Remaining Excess of Loss Reinsurance Coverages Home Re 2018-1 Ltd. (Oct. - 2018) July 1, 2016 - December 31, 2017 October 25, 2025 $ 167,779 $ 260,957 $ 168,691 $ 318,636 Home Re 2019-1 Ltd. (May - 2019) January 1, 2018 - March 31, 2019 May 25, 2026 185,636 271,021 — — Total $ 353,415 $ 531,978 $ 168,691 $ 318,636 (1) We have the right to terminate the excess-of-loss reinsurance agreements under certain circumstances and on any payment date on or after the respective termination option date.
Schedule of total assets of Home Re Entities	Table 9.4 presents the total assets of Home Re Entities as of December 31, 2019 and December 31, 2018. Home Re Entities total assets Table 9.4 (In thousands) Home Re Entity Total VIE Assets December 31, 2019 Home Re 2018-01 Ltd. $ 269,451 Home Re 2019-01 Ltd. $ 283,150 December 31, 2018 Home Re 2018-1 Ltd. $ 318,636

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
Other Comprehensive Income (Loss) (Tables)	Dec. 31, 2019
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, 2019 , 2018 and 2017 are included in table 10.1 below. Components of other comprehensive income (loss) Table 10.1 (In thousands) 2019 2018 2017 Net unrealized investment gains (losses) arising during the year $ 220,139 $ (81,834 ) $ 69,052 Income tax (expense) benefit (46,229 ) 17,188 (21,505 ) Net of taxes 173,910 (64,646 ) 47,547 Net changes in benefit plan assets and obligations 29,129 (19,958 ) (8,983 ) Income tax (expense) benefit (6,117 ) 4,191 3,144 Net of taxes 23,012 (15,767 ) (5,839 ) Net changes in unrealized foreign currency translation adjustment — — 45 Income tax benefit (expense) — — (14 ) Net of taxes — — 31 Total other comprehensive income (loss) 249,268 (101,792 ) 60,114 Total income tax (expense) benefit, net (52,346 ) 21,379 (18,375 ) Total other comprehensive income (loss), net of tax $ 196,922 $ (80,413 ) $ 41,739
Reclassification out of accumulated other comprehensive income	The pretax and related income tax benefit (expense) components of the amounts reclassified from our accumulated other comprehensive income (loss) ( "AOCI", "AOCL") to our consolidated statements of operations for the years ended December 31, 2019 , 2018 and 2017 are included in table 10.2 below. Reclassifications from Accumulated Other Comprehensive Income (Loss) Table 10.2 (In thousands) 2019 2018 2017 Reclassification adjustment for net realized (losses) gains included in net income (1) $ 3,637 $ (7,037 ) $ (2,580 ) Income tax (expense) benefit (763 ) 1,477 903 Net of taxes 2,874 (5,560 ) (1,677 ) Reclassification adjustment related to benefit plan assets and obligations (2) (8,097 ) (2,232 ) 906 Income tax benefit (expense) 1,701 469 (317 ) Net of taxes (6,396 ) (1,763 ) 589 Total reclassifications (4,460 ) (9,269 ) (1,674 ) Total income tax benefit, net 938 1,946 586 Total reclassifications, net of tax $ (3,522 ) $ (7,323 ) $ (1,088 ) (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.
Accumulated other comprehensive income (loss)	A roll-forward of AOCI (AOCL) for the years ended December 31, 2019 , 2018 , and 2017 , including amounts reclassified from AOCI (AOCL), is included in table 10.3 below. Roll-forward of Accumulated Other Comprehensive Income (Loss) 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, 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 ) Other comprehensive income (loss) before reclassifications 176,784 16,616 — 193,400 Less: Amounts reclassified from AOCL 2,874 (6,396 ) — (3,522 ) Balance, December 31, 2019, net of tax $ 138,521 $ (65,813 ) $ — 72,708

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
Benefit Plans (Tables)	Dec. 31, 2019
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, 2019 , 2018 , and 2017 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, 2019 and 2018 . Components of net periodic benefit cost Table 11.1 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2017 12/31/2019 12/31/2018 12/31/2017 1. Company Service Cost $ 8,345 $ 10,530 $ 9,556 $ 1,345 $ 1,160 $ 813 2. Interest Cost 15,705 15,095 15,475 1,130 834 706 3. Expected Return on Assets (19,466 ) (22,250 ) (20,099 ) (5,785 ) (6,359 ) (5,248 ) 4. Other Adjustments — — — — — — Subtotal 4,584 3,375 4,932 (3,310 ) (4,365 ) (3,729 ) 5. Amortization of: a. Net Transition Obligation/(Asset) — — — — — — b. Net Prior Service Cost/(Credit) (281 ) (351 ) (426 ) (34 ) (4,104 ) (6,649 ) c. Net Losses/(Gains) 8,412 6,937 6,169 — (250 ) — Total Amortization 8,131 6,586 5,743 (34 ) (4,354 ) (6,649 ) 6. Net Periodic Benefit Cost 12,715 9,961 10,675 (3,344 ) (8,719 ) (10,378 ) 7. Cost of settlements 1,933 — — — — — 8. Total Expense for Year $ 14,648 $ 9,961 $ 10,675 $ (3,344 ) $ (8,719 ) $ (10,378 )
Development of funded status	Development of funded status Table 11.2 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 Actuarial Value of Benefit Obligations 1. Measurement Date 12/31/2019 12/31/2018 12/31/2019 12/31/2018 2. Accumulated Benefit Obligation $ 412,939 $ 375,562 $ 27,496 $ 28,085 Funded Status/Asset (Liability) on the Consolidated Balance Sheet 1. Projected Benefit Obligation $ (413,350 ) $ (376,153 ) $ (27,496 ) $ (28,085 ) 2. Plan Assets at Fair Value 402,691 359,719 99,590 77,762 3. Funded Status - Overfunded/Asset N/A N/A $ 72,094 $ 49,677 4. Funded Status - Underfunded/Liability (10,659 ) (16,434 ) N/A N/A Accumulated other comprehensive (income) loss Table 11.3 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Net Actuarial (Gain)/Loss $ 99,826 $ 110,321 $ (18,005 ) $ 939 2. Net Prior Service Cost/(Credit) (1,237 ) (1,513 ) 2,724 2,690 3. Net Transition Obligation/(Asset) — — — — 4. Total at Year End $ 98,589 $ 108,808 $ (15,281 ) $ 3,629
Change in projected benefit obligation	Table 11.4 shows the changes in the projected benefit obligation for 2019 and 2018 . Change in projected benefit / accumulated benefit Table 11.4 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Benefit Obligation at Beginning of Year $ 376,153 $ 417,770 $ 28,085 $ 24,716 2. Company Service Cost 8,345 10,530 1,345 1,160 3. Interest Cost 15,705 15,095 1,130 834 4. Plan Participants' Contributions — — 382 475 5. Net Actuarial (Gain)/Loss due to Assumption Changes 43,302 (36,132 ) (1,215 ) (1,209 ) 6. Net Actuarial (Gain)/Loss due to Plan Experience 3,811 2,487 (860 ) (692 ) 7. Benefit Payments from Fund (1) (30,829 ) (32,674 ) (826 ) (1,077 ) 8. Benefit Payments Directly by Company (3,105 ) (908 ) — — 9. Plan Amendments (5 ) (15 ) — 3,928 10. Other Adjustment — — (545 ) (50 ) 11. Settlement (Gain)/Loss (27 ) — — — 11. Benefit Obligation at End of Year $ 413,350 $ 376,153 $ 27,496 $ 28,085 (1) Includes lump sum payments of $18.5 million and $20.9 million in 2019 and 2018 , 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 2019 and 2018 . Change in plan assets Table 11.5 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Fair Value of Plan Assets at Beginning of Year $ 359,719 $ 401,142 $ 77,762 $ 85,303 2. Company Contributions 10,205 10,908 — — 3. Plan Participants' Contributions — — 382 475 4. Benefit Payments from Fund (30,829 ) (32,674 ) (826 ) (1,077 ) 5. Benefit Payments paid directly by Company (3,105 ) (908 ) — — 6. Actual Return on Assets 70,262 (19,583 ) 22,654 (6,464 ) 7. Other Adjustment (3,561 ) 834 (382 ) (475 ) 8. Fair Value of Plan Assets at End of Year $ 402,691 $ 359,719 $ 99,590 $ 77,762
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) 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. AOCI in Prior Year $ 108,808 $ 108,054 $ 3,629 $ (15,576 ) 2. Increase/(Decrease) in AOCI a. Recognized during year - Prior Service (Cost)/Credit 281 351 34 4,104 b. Recognized during year - Net Actuarial (Losses)/Gains (8,412 ) (6,937 ) — 250 c. Occurring during year - Prior Service Cost (5 ) (15 ) — 3,928 d. Occurring during year - Net Actuarial Losses/(Gains) (150 ) 7,355 (18,944 ) 10,923 e. Occurring during year - Net Settlement Losses/(Gains) (1,933 ) — — — 3. AOCI in Current Year $ 98,589 $ 108,808 $ (15,281 ) $ 3,629
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, 2020 . Amortization expected to be recognized during fiscal year ending Table 11.7 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2019 1. Amortization of Net Transition Obligation/(Asset) $ — $ — 2. Amortization of Prior Service Cost/(Credit) (248 ) 51 3. Amortization of Net Losses/(Gains) 6,534 (761 )
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 12/31/2019 12/31/2018 12/31/2019 12/31/2018 Weighted-Average Assumptions Used to Determine Benefit Obligations at year end 1. Discount Rate 3.45 % 4.40 % 3.20 % 4.25 % 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 4.40 % 3.75 % 4.25 % 3.55 % 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 6.00 % 6.25 % 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 12/31/2019 12/31/2018 12/31/2019 12/31/2018 1. Equity Securities 23 % 23 % 100 % 100 % 2. Debt Securities 77 % 77 % — % — % 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 ● Global low volatility Return seeking bridge Downside protection in the event of a declining equity market ● Enduring asset ● Durable company
Minimum and maximum allocation ranges for fixed income securities and equity securities	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 %
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) 12/31/2019 12/31/2019 Company Contributions for the Year Ending: 1. Current $ 10,205 $ — 2. Current + 1 12,350 — Benefits payments - total Table 11.13 Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits (In thousands) 12/31/2019 12/31/2019 Actual Benefit Payments for the Year Ending: 1. Current $ 33,934 $ 989 Expected Benefit Payments for the Year Ending: 2. Current + 1 34,943 1,600 3. Current + 2 31,008 1,847 4. Current + 3 30,981 2,087 5. Current + 4 31,175 2,254 6. Current + 5 30,547 2,367 7. Current + 6 - 10 141,768 11,874
Effect of a 1% change in the health care trend rate assumption	A one 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 $ 380 $ (328 ) Effect on postretirement benefit obligation 2,528 (2,239 )
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	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, 2019 and 2018 . There were no securities that used Level 3 inputs. Pension plan assets at fair value as of December 31, 2019 Table 11.10a (In thousands) Level 1 Level 2 Total Domestic Mutual Funds $ 7,325 $ — $ 7,325 Corporate Bonds — 203,684 203,684 U.S. Government Securities 32,166 2,511 34,677 Municipal Bonds — 38,998 38,998 Foreign Bonds — 34,024 34,024 ETFs — — — Pooled Equity Accounts — 83,983 83,983 Total Assets at fair value $ 39,491 $ 363,200 $ 402,691 Pension plan assets at fair value as of December 31, 2018 Table 11.10b (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
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, 2019 and 2018 . All are Level 1 assets. Other postretirement benefits plan assets at fair value as of December 31, 2019 Table 11.11a (In thousands) Level 1 Total Domestic Mutual Funds $ 77,640 $ 77,640 International Mutual Funds 21,950 21,950 Total Assets at fair value $ 99,590 $ 99,590 Other postretirement benefits plan assets at fair value as of December 31, 2018 Table 11.11b (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

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Net deferred tax assets and liabilities	Net deferred tax assets and liabilities as of December 31, 2019 and 2018 are as follows: Deferred tax assets and liabilities Table 12.1 (In thousands) 2019 2018 Total deferred tax assets $ 63,533 $ 83,082 Total deferred tax liabilities (57,791 ) (13,898 ) Net deferred tax asset $ 5,742 $ 69,184
Components of the net deferred tax asset (liability)	Table 12.2 includes the components of the net deferred tax asset as of December 31, 2019 and 2018 . Deferred tax components Table 12.2 (In thousands) 2019 2018 Unearned premium reserves $ 30,487 $ 31,808 Benefit plans (10,790 ) (5,047 ) Loss reserves 2,175 3,113 Unrealized (appreciation) depreciation in investments (36,822 ) 9,407 Mortgage investments 8,359 8,307 Deferred compensation 9,270 8,662 AMT credit carryforward 8,303 17,521 Other, net (5,240 ) (4,587 ) Net deferred tax asset $ 5,742 $ 69,184
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) 2019 2018 2017 Current Federal $ 162,911 $ (16,272 ) $ 73,348 Deferred Federal 11,860 185,598 351,677 Other (557 ) 4,727 3,710 Provision for income taxes $ 174,214 $ 174,053 $ 428,735
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 2019 2018 2017 Federal statutory income tax rate 21.0 % 21.0 % 35.0 % Additional income tax provision (benefit) related to the rate decrease included in the Tax Act — % — % 17.0 % Additional income tax provision (benefit) related to IRS litigation — % (0.3 )% 3.7 % Tax exempt municipal bond interest (0.6 )% (0.7 )% (1.4 )% Other, net 0.1 % 0.6 % 0.4 % Effective tax rate 20.5 % 20.6 % 54.7 %
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 Balance at beginning of year $ 142,821 $ 108,245 Additions for tax positions of prior years — 35,003 Reductions for tax positions of prior years (3,070 ) (427 ) Settlements (139,751 ) — Balance at end of year $ — $ 142,821

Statutory Information (Tables)

Statutory Information (Tables)	12 Months Ended
Statutory Information (Tables)	Dec. 31, 2019
Statutory Capital [Abstract]
Summary of amounts disclosed under statutory accounting practices	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) 2019 2018 2017 Statutory net income $ 305,857 $ 375,484 $ 310,776 Statutory policyholders' surplus 1,619,069 1,683,058 1,622,115 Contingency reserve 3,021,055 2,442,996 1,896,701 For the years ended December 31, 2019 , 2018 , and 2017 there were no surplus contributions made to MGIC or distributions from other insurance subsidiaries to us. Dividends paid by MGIC are shown in table 14.2 below. Surplus contributions and dividends of insurance subsidiaries Table 14.2 Years Ended December 31, (In thousands) 2019 2018 2017 Dividends paid by MGIC to the parent company $ 280,000 220,000 140,000

Share-based Compensation Plans

Share-based Compensation Plans (Tables)	12 Months Ended
Share-based Compensation Plans (Tables)	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Summary of restricted stock or restricted stock unit activity	Table 15.1 summarizes restricted stock or restricted stock unit (collectively called “restricted stock”) activity during 2019 . Restricted stock Table 15.1 Weighted Average Grant Date Fair Market Value Shares Restricted stock outstanding at December 31, 2018 $ 12.27 3,583,506 Granted 11.92 2,002,500 Vested 9.37 (1,067,890 ) Forfeited 13.67 (367,722 ) Restricted stock outstanding at December 31, 2019 $ 12.81 4,150,394

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2019
Leases [Abstract]
Lessee, operating lease, liability, maturity	Table 16.1 shows minimum the future operating lease payments as of December 31, 2019 . Minimum future operating lease payments Table 16.1 (In thousands) Amount 2020 $ 1,204 2021 588 2022 380 2023 83 2024 and thereafter — Total $ 2,255
Minimum future operating lease payments	Table 16.2 shows minimum the future operating lease payments as of December 31, 2018. Minimum future operating lease payments Table 16.2 (In thousands) Amount 2019 $ 1,406 2020 1,069 2021 371 2022 161 2023 and thereafter — Total $ 3,007

Unaudited Quarterly Financial_2

Unaudited Quarterly Financial Data (Tables)	12 Months Ended
Unaudited Quarterly Financial Data (Tables)	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Unaudited quarterly financial data	Unaudited quarterly financial data - current year: Table: 18.1a 2019: Quarter Full (In thousands, except per share data) First Second Third Fourth Year Net premiums earned $ 249,762 $ 247,102 $ 267,857 $ 266,267 $ 1,030,988 Investment income, net of expenses 40,585 42,423 42,715 41,322 167,045 Realized (losses) gains (526 ) 307 4,205 1,320 5,306 Other revenue 1,830 2,485 3,606 2,717 10,638 Loss incurred, net 39,064 21,836 33,985 23,690 118,575 Underwriting and other expenses, net 61,650 59,270 61,278 65,227 247,425 Provision for income tax 38,996 43,433 46,186 45,599 174,214 Net income 151,941 167,778 176,934 177,110 673,763 Income per share (a) (b) : Basic 0.43 0.47 0.50 0.51 1.91 Diluted 0.42 0.46 0.49 0.49 1.85 Unaudited quarterly financial statements - prior year: Table: 18.1b 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 gains (losses) (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 (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.

Nature of Business (Details)

Nature of Business (Details) $ in Billions	Dec. 31, 2019USD ($)
Nature of Business [Abstract]
Direct domestic primary insurance in force	$ 222.3
Direct domestic primary risk in force	$ 57.2

Significant Accounting Polici_4

Significant Accounting Policies (Details)	12 Months Ended
Significant Accounting Policies (Details)	Dec. 31, 2019USD ($)Payment	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Home office and equipment [Abstract]
Accumulated depreciation of home office and equipment	$ 43,000,000	$ 38,100,000	$ 33,900,000
Depreciation expense of home office and equipment	$ 6,500,000	6,000,000	5,400,000
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)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basic earnings per share [Abstract]
Net income	$ 177,110	$ 176,934	$ 167,778	$ 151,941	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 673,763	$ 670,097	$ 355,761
Weighted average common shares outstanding - basic (in shares)									352,827	365,406	362,380
Basic earnings per share (in dollars per share)	$ 0.51	$ 0.50	$ 0.47	$ 0.43	$ 0.44	$ 0.50	$ 0.51	$ 0.39	$ 1.91	$ 1.83	$ 0.98
Diluted earnings per share [Abstract]
Net income	$ 177,110	$ 176,934	$ 167,778	$ 151,941	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 673,763	$ 670,097	$ 355,761
Diluted income available to common shareholders									$ 692,027	$ 688,361	$ 373,404
Weighted-average shares - basic (in shares)									352,827	365,406	362,380
Effect of dilutive securities [Abstract]
Weighted-average shares - diluted (in shares)									373,924	386,078	394,766
Diluted income per share (in dollars per share)	$ 0.49	$ 0.49	$ 0.46	$ 0.42	$ 0.43	$ 0.49	$ 0.49	$ 0.38	$ 1.85	$ 1.78	$ 0.95
Federal statutory income tax rate (in hundredths)									21.00%	21.00%	35.00%
2% Convertible Senior Notes due 2020
Diluted earnings per share [Abstract]
Dilutive securities									$ 0	$ 0	$ 907
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)									0	0	8,317
Stated interest rate (in hundredths)											2.00%
5% Convertible Senior Notes due 2017
Diluted earnings per share [Abstract]
Dilutive securities									$ 0	$ 0	$ 1,709
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)									0	0	3,548
Stated interest rate (in hundredths)											5.00%
9% Convertible Junior Subordinated Debentures due 2063
Diluted earnings per share [Abstract]
Dilutive securities									$ 18,264	$ 18,264	$ 15,027
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)									19,028	19,028	19,028
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)									2,069	1,644	1,493

Investments (Details)

Investments (Details)	12 Months Ended
Investments (Details)	Dec. 31, 2019USD ($)security	Dec. 31, 2018USD ($)security	Dec. 31, 2017USD ($)
Debt Securities, Available-for-sale [Line Items]
Total at end of period	$ 5,562,550,000	$ 5,196,784,000
Total at end of period	5,737,892,000	5,151,987,000
Other than temporary impairments recorded in other comprehensive (loss) income	0	0
Assets held by insurance regulatory requirements	13,900,000	13,500,000
Assets held in trust for the benefit of contractual counterparties	$ 89,900,000	26,300,000
Collateral, principal balance of FHLB (as a percent)	102.00%
Collateral, principal balance of FHLB	$ 165,700,000
Maturities, Amortized Cost [Abstract]
Due in one year or less	425,739,000
Due after one year through five years	1,911,433,000
Due after five years through ten years	1,031,056,000
Due after ten years	1,094,252,000
Total debt securities with single maturity date	4,462,480,000
Total at end of period	5,562,550,000	5,196,784,000
Maturities, Fair Value [Abstract]
Due in one year or less	427,616,000
Due after one year through five years	1,952,278,000
Due after five years through ten years	1,088,012,000
Due after ten years	1,167,284,000
Total debt securities with single maturity date	4,635,190,000
Total at end of period	5,737,892,000	5,151,987,000
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Equity securities, cost	17,188,000	3,993,000
Equity securities, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	17,328,000	3,932,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	624,334,000	2,026,193,000
12 months or greater	379,411,000	1,554,704,000
Total	1,003,745,000	3,580,897,000
Less than 12 months	(5,426,000)	(28,520,000)
12 months or greater	(4,476,000)	(49,384,000)
Total	$ (9,902,000)	$ (77,904,000)
Number of securities in unrealized loss position \| security	217	721
For securities in an unrealized loss position, percentage of fair value to amortized cost (in hundredths)	99.00%
For securities in an unrealized loss position, percentage backed by the U.S. Government (in hundredths)	28.00%
Total fixed income securities
Debt Securities, Available-for-sale [Line Items]
Total at end of period	$ 5,562,550,000	$ 5,196,784,000
Gross Unrealized Gains	185,244,000	33,107,000
Gross Unrealized Losses	(9,902,000)	(77,904,000)
Total at end of period	5,737,892,000	5,151,987,000
Maturities, Amortized Cost [Abstract]
Total at end of period	5,562,550,000	5,196,784,000
Maturities, Fair Value [Abstract]
Total at end of period	5,737,892,000	5,151,987,000
Proceeds from sale of fixed income securities available for sale	228,100,000	365,600,000	$ 246,900,000
Gross realized gains	7,100,000	700,000	1,600,000
Gross realized losses	3,500,000	3,800,000	1,400,000
Recognized other than temporary impairments	100,000	1,800,000	$ 0
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Total at end of period	195,176,000	167,655,000
Gross Unrealized Gains	1,237,000	597,000
Gross Unrealized Losses	(210,000)	(1,076,000)
Total at end of period	196,203,000	167,176,000
Maturities, Amortized Cost [Abstract]
Total at end of period	195,176,000	167,655,000
Maturities, Fair Value [Abstract]
Total at end of period	196,203,000	167,176,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	57,301,000	23,710,000
12 months or greater	5,806,000	69,146,000
Total	63,107,000	92,856,000
Less than 12 months	(200,000)	(15,000)
12 months or greater	(10,000)	(1,061,000)
Total	(210,000)	(1,076,000)
Obligations of U.S. states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Total at end of period	1,555,394,000	1,701,826,000
Gross Unrealized Gains	99,328,000	29,259,000
Gross Unrealized Losses	(857,000)	(10,985,000)
Total at end of period	1,653,865,000	1,720,100,000
Maturities, Amortized Cost [Abstract]
Total at end of period	1,555,394,000	1,701,826,000
Maturities, Fair Value [Abstract]
Total at end of period	1,653,865,000	1,720,100,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	74,859,000	316,655,000
12 months or greater	6,957,000	358,086,000
Total	81,816,000	674,741,000
Less than 12 months	(847,000)	(3,875,000)
12 months or greater	(10,000)	(7,110,000)
Total	(857,000)	(10,985,000)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Total at end of period	2,711,910,000	2,439,173,000
Gross Unrealized Gains	76,220,000	2,103,000
Gross Unrealized Losses	(3,008,000)	(40,514,000)
Total at end of period	2,785,122,000	2,400,762,000
Maturities, Amortized Cost [Abstract]
Total at end of period	2,711,910,000	2,439,173,000
Maturities, Fair Value [Abstract]
Total at end of period	2,785,122,000	2,400,762,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	221,357,000	1,272,279,000
12 months or greater	43,505,000	785,627,000
Total	264,862,000	2,057,906,000
Less than 12 months	(2,847,000)	(18,130,000)
12 months or greater	(161,000)	(22,384,000)
Total	(3,008,000)	(40,514,000)
ABS
Debt Securities, Available-for-sale [Line Items]
Total at end of period	227,376,000	111,953,000
Gross Unrealized Gains	2,466,000	226,000
Gross Unrealized Losses	(178,000)	(146,000)
Total at end of period	229,664,000	112,033,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	227,376,000
Total at end of period	227,376,000	111,953,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	229,664,000
Total at end of period	229,664,000	112,033,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	21,542,000	51,324,000
12 months or greater	3,851,000	0
Total	25,393,000	51,324,000
Less than 12 months	(118,000)	(146,000)
12 months or greater	(60,000)	0
Total	(178,000)	(146,000)
RMBS
Debt Securities, Available-for-sale [Line Items]
Total at end of period	271,384,000	189,238,000
Gross Unrealized Gains	429,000	32,000
Gross Unrealized Losses	(3,227,000)	(10,309,000)
Total at end of period	268,586,000	178,961,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	271,384,000
Total at end of period	271,384,000	189,238,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	268,586,000
Total at end of period	268,586,000	178,961,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	105,443,000	24,000
12 months or greater	110,452,000	178,573,000
Total	215,895,000	178,597,000
Less than 12 months	(461,000)	0
12 months or greater	(2,766,000)	(10,309,000)
Total	(3,227,000)	(10,309,000)
CMBS
Debt Securities, Available-for-sale [Line Items]
Total at end of period	274,234,000	276,352,000
Gross Unrealized Gains	5,531,000	888,000
Gross Unrealized Losses	(779,000)	(9,580,000)
Total at end of period	278,986,000	267,660,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	274,234,000
Total at end of period	274,234,000	276,352,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	278,986,000
Total at end of period	278,986,000	267,660,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	62,388,000	65,704,000
12 months or greater	11,852,000	163,272,000
Total	74,240,000	228,976,000
Less than 12 months	(728,000)	(1,060,000)
12 months or greater	(51,000)	(8,520,000)
Total	(779,000)	(9,580,000)
CLOs
Debt Securities, Available-for-sale [Line Items]
Total at end of period	327,076,000	310,587,000
Gross Unrealized Gains	33,000	2,000
Gross Unrealized Losses	(1,643,000)	(5,294,000)
Total at end of period	325,466,000	305,295,000
Maturities, Amortized Cost [Abstract]
Debt securities without single maturity date	327,076,000
Total at end of period	327,076,000	310,587,000
Maturities, Fair Value [Abstract]
Debt securities without single maturity date	325,466,000
Total at end of period	325,466,000	305,295,000
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months	81,444,000	296,497,000
12 months or greater	196,988,000	0
Total	278,432,000	296,497,000
Less than 12 months	(225,000)	(5,294,000)
12 months or greater	(1,418,000)	0
Total	(1,643,000)	(5,294,000)
Equity securities
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Equity securities, cost	17,188,000	3,993,000
Gross gains	154,000	11,000
Gross losses	(14,000)	(72,000)
Equity securities, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	17,328,000	3,932,000
Proceeds from sale of equity securities	1,700,000	4,900,000
Gross realized gains on equity securities	1,600,000	3,700,000
Recognized net losses on equity securities still held	$ 201,000	$ 84,000

Investments, Investment Income

Investments, Investment Income By Category (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									$ 171,347	$ 145,006	$ 124,378
Investment expenses									(4,302)	(3,675)	(3,507)
Net investment income	$ 41,322	$ 42,715	$ 42,423	$ 40,585	$ 38,328	$ 36,380	$ 34,502	$ 32,121	167,045	141,331	120,871
Fixed income securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									165,523	140,539	122,105
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									406	228	206
Cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									4,444	3,423	1,447
Other
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income									$ 974	$ 816	$ 620

Investments, Gain (Loss) on Inv

Investments, Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gain (Loss) on Securities [Line Items]
Change in unrealized gains (losses)	$ 220,139	$ (81,834)	$ 69,052
Available-for-Sale Securities \| Fixed income
Gain (Loss) on Securities [Line Items]
Change in unrealized gains (losses)	220,139	(81,834)	69,026
Available-for-Sale Securities \| Equity Securities
Gain (Loss) on Securities [Line Items]
Change in unrealized gains (losses)	0	0	39
Available-for-Sale Securities \| Other
Gain (Loss) on Securities [Line Items]
Change in unrealized gains (losses)	$ 0	$ 0	$ (13)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	$ 5,737,892	$ 5,151,987
Equity securities, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	17,328	3,932
Other	164,693	96,403
Real estate acquired	7,252	14,535
Total assets	5,927,165	5,266,857
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	164,693	96,403
Real estate acquired	0	0
Total assets	216,261	142,599
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	0	0
Real estate acquired	0	0
Total assets	5,703,652	5,109,710
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	0	0
Real estate acquired	7,252	14,535
Total assets	7,252	14,548
Total fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	5,737,892	5,151,987
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	34,240	42,264
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	5,703,652	5,109,710
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	0	13
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	196,203	167,176
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	34,240	42,264
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	161,963	124,912
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	1,653,865	1,720,100
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	1,653,865	1,720,087
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	0	13
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income, available-for-sale	2,785,122	2,400,762
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	2,785,122	2,400,762
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	229,664	112,033
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	229,664	112,033
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	268,586	178,961
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	268,586	178,961
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	278,986	267,660
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	278,986	267,660
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	325,466	305,295
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	325,466	305,295
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, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	17,328	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, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	17,328	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, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	0	0
Equity securities \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value (cost, 2019 - $17,188; 2018 - $3,993)	$ 0	$ 0

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 13	$ 4,539	$ 4,959
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
Included in earnings and reported as losses incurred, net	0	0	0
Acquisitions	0	0	0
Sales	(13)	(5,089)	(420)
Balance at end of period	0	13	4,539
Total fixed income securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	13	271	691
Transfers out of Level 3		0
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as net realized investment gains		0
Included in earnings and reported as losses incurred, net	0	0	0
Acquisitions	0	0	0
Sales	(13)	(258)	(420)
Balance at end of period	0	13	271
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	0	4,268	4,268
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
Included in earnings and reported as losses incurred, net	0	0	0
Acquisitions	0	0	0
Sales	0	(4,831)	0
Balance at end of period	0	0	4,268
Real Estate Acquired
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	14,535	12,713	11,748
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	(476)	(1,995)	(1,315)
Acquisitions	24,204	33,912	34,749
Sales	(31,011)	(30,095)	(32,469)
Balance at end of period	$ 7,252	$ 14,535	$ 12,713

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
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]
Other invested assets	$ 3,100	$ 3,100
FHLB Advance	155,000	155,000
5.75% Notes	420,867	419,713
9% Debentures	256,872	256,872
Total financial liabilities	832,739	831,585
Fair Value \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	3,100	3,100
FHLB Advance	156,422	150,551
5.75% Notes	471,827	425,791
9% Debentures	346,289	338,069
Total financial liabilities	$ 974,538	$ 914,411

Debt Summary of Obligations (De

Debt Summary of Obligations (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 832,700,000	$ 831,600,000
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	$ 420,900,000	419,700,000
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)

Debt (Details)	12 Months Ended
Debt (Details)	Dec. 31, 2019USD ($)Period$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	May 31, 2019USD ($)
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	$ 50,800,000	$ 51,300,000	$ 57,800,000
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	74.4718
Principal amount of notes used in determining conversion rate	$ 1,000
Initial conversion price (in dollars per share) \| $ / shares	$ 13.43
Period preceding election to convert	5 days
Convertible debt, number of equity instruments reserved for conversion (in shares) \| shares	19,100,000
Closing sale price of our common stock for consideration of redemption (in dollars per share) \| $ / shares	$ 17.46
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%
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				$ 175,000,000

Loss Reserves - Narrative (Deta

Loss Reserves - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
Loss Reserves - Narrative (Details) $ in Thousands	Dec. 31, 2017loan	Dec. 31, 2019USD ($)Paymentloan	Dec. 31, 2018USD ($)loan	Dec. 31, 2017USD ($)loan
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Minimum number of payments past due to be in default \| Payment		2
Premium refund liability, expected claim payments \| $		$ 30,000	$ 40,000
Percentage of prior year default inventory resolved (in hundredths)		69.00%	73.00%	67.00%
Other items removed from inventory \| loan		639	1,578	1,337
Losses for unpaid claims and adjustment expense \| $		$ 235,551	$ 327,743	$ 493,300
Default notices for loans in IADAs \| loan	9,294
Default inventory in FEMA individual assistance disaster areas \| loan	12,446			12,446
Percent of inventory in default for more than 36 consecutive months	45.00%	36.00%	38.00%	45.00%
Pool insurance notice inventory (in number of loans) \| loan	1,309	653	859	1,309
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 \| $		$ 30,000	$ 50,000	$ 54,000
Settlements for 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 \| $		$ 23,500

Loss Reserves - Reconciliation

Loss Reserves - Reconciliation of Changes in Loss Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Reserve [Roll Forward]
Reserve at beginning of year	$ 674,019	$ 985,635	$ 1,438,813
Less reinsurance recoverable	21,641	33,328	48,474	$ 50,493
Net reserve at beginning of year	533,693	640,691	937,161	$ 1,388,320
Losses incurred: [Abstract]
Current year	189,581	203,928	284,913
Prior years	(71,006)	(167,366)	(231,204)
Total losses incurred	118,575	36,562	53,709
Losses paid [Abstract]
Current year	4,018	7,298	11,267
Prior years	235,551	327,743	493,300
Reinsurance terminations	(13,996)	(2,009)	301
Total losses paid	225,573	333,032	504,868
Reserve at end of year	$ 555,334	$ 674,019	$ 985,635

Loss Reserves - Prior Year Loss

Loss Reserves - Prior Year Loss Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	$ (71,006)	$ (167,366)	$ (231,204)
Decrease in estimated claim rate on primary delinquencies
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	(112,000)	(213,000)	(248,000)
(Decrease) increase in estimated severity on primary delinquencies
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior years	(1,000)	29,000	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	$ 42,000	$ 17,000	$ 8,000

Loss Reserves - Default Invento

Loss Reserves - Default Inventory Reconciliation (Details) - loan	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Primary Default Inventory [Roll Forward]
Beginning delinquent inventory	32,898	46,556	50,282
New Notices	54,239	54,448	68,268
Cures	(52,035)	(60,511)	(61,094)
Paid claims	(4,267)	(5,750)	(9,206)
Rescissions and denials	(168)	(267)	(357)
Other items removed from inventory	(639)	(1,578)	(1,337)
Ending delinquent inventory	30,028	32,898	46,556

Loss Reserves - Aging of Primar

Loss Reserves - Aging of Primary Default Inventory and Number of Delinquent Payments (Details) - loan	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Aging of the Primary Default Inventory [Abstract]
3 months or less	9,447	9,829	17,119
4 - 11 months	9,664	9,655	12,050
12 months or more	10,917	13,414	17,387
Total primary default inventory	30,028	32,898	46,556	50,282
3 months or less (in hundredths)	32.00%	30.00%	37.00%
4 - 11 months (in hundredths)	32.00%	29.00%	26.00%
12 months or more (in hundredths)	36.00%	41.00%	37.00%
Total primary default inventory (in hundredths)	100.00%	100.00%	100.00%
Primary claims received inventory included in ending default inventory	538	809	954

Reinsurance - Summary of Reinsu

Reinsurance - Summary of Reinsurance Agreements (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Premiums Earned, Net [Abstract]
Premiums earned, direct									$ 1,155,240	$ 1,084,748	$ 1,059,973
Premiums earned, assumed									5,085	1,805	509
Premiums earned, ceded									(129,337)	(111,391)	(125,735)
Net premiums earned	$ 266,267	$ 267,857	$ 247,102	$ 249,762	$ 245,665	$ 250,426	$ 246,964	$ 232,107	1,030,988	975,162	934,747
Policyholder Benefits and Claims Incurred, Net [Abstract]
Losses incurred, direct									130,100	43,060	74,727
Losses incurred, assumed									(125)	331	183
Losses incurred, ceded									(11,400)	(6,829)	(21,201)
Net losses incurred	$ 23,690	$ 33,985	$ 21,836	$ 39,064	$ 27,685	$ (1,518)	$ (13,455)	$ 23,850	$ 118,575	$ 36,562	$ 53,709

Reinsurance - Narrative (Detail

Reinsurance - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended		12 Months Ended
Reinsurance - Narrative (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves		$ 21,641,000				$ 21,641,000	$ 33,328,000	$ 48,474,000	$ 50,493,000
Ceded premiums earned						129,337,000	111,391,000	$ 125,735,000
Quota Share Reinsurance Agreement, 2019
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%
Cede rate, option 1						25.00%
Cede rate, option 2						20.00%
Ceding commission, percentage						20.00%
Loss ratio						62.00%
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	$ 6,800,000	$ 0
Threshold for private mortgage insurer eligibility requirements for termination election						90.00%
Quota share, percentage		15.00%	30.00%
Loss ratio						68.00%
Quota Share Reinsurance Agreements, Excluding Captives
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves		$ 21,600,000				$ 21,600,000	33,200,000
Quota Share Reinsurance Agreement, 2020 \| 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%
Cede rate, option 1					25.00%
Cede rate, option 2					20.00%
Loss ratio					62.00%
Quota Share Reinsurance Agreement, 2021 \| 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				17.50%
Cede rate, option 1				14.50%
Cede rate, option 2				12.00%
Loss ratio				62.00%
Excess of Loss Reinsurance Agreements, Home Re Entities
Effects of Reinsurance [Line Items]
Amortization period excess of loss reinsurance coverage						10 years
Ceded premiums earned						$ 17,600,000	$ 2,800,000
Home Re special purpose insurers
Effects of Reinsurance [Line Items]
Percent of total trust assets invested in cash or direct U.S. federal government obligations						99.50%
Home Re special purpose insurers \| Mortgage Insurance Linked Notes
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes						10 years

Reinsurance - Quota Share Reins

Reinsurance - Quota Share Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effects of Reinsurance [Line Items]
Ceded losses incurred	$ 11,400	$ 6,829	$ 21,201
Quota Share Reinsurance Agreements, Excluding Captives
Effects of Reinsurance [Line Items]
Ceded premiums written and earned, net of profit commission	111,550	108,337	120,974
Ceded losses incurred	11,395	6,543	22,336
Ceding commisisons	48,793	51,201	49,321
Profit commission	$ 139,179	$ 147,667	$ 125,629

Reinsurance - Excess of Loss Re

Reinsurance - Excess of Loss Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Home Re 2018-1
Effects of Reinsurance [Line Items]
Remaining First Layer Retention	$ 167,779	$ 168,691
Remaining Excess of Loss Reinsurance Coverages	260,957	318,636
Home Re 2019-1
Effects of Reinsurance [Line Items]
Remaining First Layer Retention	185,636	0
Remaining Excess of Loss Reinsurance Coverages	271,021	0
Home Re special purpose insurers
Effects of Reinsurance [Line Items]
Remaining First Layer Retention	353,415	168,691
Remaining Excess of Loss Reinsurance Coverages	$ 531,978	$ 318,636

Reinsurance - Home Re Entities

Reinsurance - Home Re Entities Total Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Home Re 2018-1
Effects of Reinsurance [Line Items]
Total VIE Assets	$ 269,451	$ 318,636
Home Re 2019-1
Effects of Reinsurance [Line Items]
Total VIE Assets	$ 283,150

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of Other Comprehensive Income (Loss) [Abstract]
Net unrealized investment gains (losses) arising during the year										$ 220,139	$ (81,834)	$ 69,052
Income tax (expense) benefit										(46,229)	17,188	(21,505)
Net of taxes										173,910	(64,646)	47,547
Net changes in benefit plan assets and obligations										29,129	(19,958)	(8,983)
Income tax (expense) benefit										(6,117)	4,191	3,144
Net of taxes										23,012	(15,767)	(5,839)
Net changes in unrealized foreign currency translation adjustment										0	0	45
Income tax benefit (expense)										0	0	(14)
Net of taxes										0	0	31
Total other comprehensive income (loss)										249,268	(101,792)	60,114
Total income tax (expense) benefit, net										(52,346)	21,379	(18,375)
Other comprehensive income (loss), net of tax										196,922	(80,413)	41,739
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications										847,977	844,150	784,496
Income tax (expense) benefit	$ (45,599)	$ (46,186)	$ (43,433)	$ (38,996)	$ (36,963)	$ (49,994)	$ (50,708)	$ (36,388)		(174,214)	(174,053)	(428,735)
Net income	177,110	$ 176,934	$ 167,778	151,941	157,746	$ 181,900	$ 186,814	143,637		673,763	670,097	355,761
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				3,581,891				3,154,526		3,581,891	3,154,526
Less: Amounts reclassified for lower enacted corporate tax rate												10,422
Balance, end of year	4,309,234				3,581,891				$ 3,154,526	4,309,234	3,581,891	3,154,526
Accumulated other comprehensive loss
Components of Other Comprehensive Income (Loss) [Abstract]
Other comprehensive income (loss), net of tax										196,922	(80,413)	41,739
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				(124,214)				(43,783)		(124,214)	(43,783)	(75,100)
Cumulative effect of adopting the accounting standard update for financial instruments									(18)			(18)
Other comprehensive income (loss) before reclassifications										193,400	(87,736)	40,651
Less: Amounts reclassified from AOCL										(3,522)	(7,323)	(1,088)
Less: Amounts reclassified for lower enacted corporate tax rate									10,400			10,422
Balance, end of year	72,708				(124,214)				(43,783)	72,708	(124,214)	(43,783)
Net unrealized gains and losses on available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				(35,389)				29,275		(35,389)	29,275	(20,797)
Cumulative effect of adopting the accounting standard update for financial instruments									(18)			(18)
Other comprehensive income (loss) before reclassifications										176,784	(70,206)	45,870
Less: Amounts reclassified from AOCL										2,874	(5,560)	(1,677)
Less: Amounts reclassified for lower enacted corporate tax rate												(2,525)
Balance, end of year	138,521				(35,389)				29,275	138,521	(35,389)	29,275
Net benefit plan assets and obligations recognized in shareholders' equity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				(88,825)				(73,058)		(88,825)	(73,058)	(54,272)
Other comprehensive income (loss) before reclassifications										16,616	(17,530)	(5,250)
Less: Amounts reclassified from AOCL										(6,396)	(1,763)	589
Less: Amounts reclassified for lower enacted corporate tax rate												12,947
Balance, end of year	(65,813)				(88,825)				(73,058)	(65,813)	(88,825)	(73,058)
Net unrealized foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of year				$ 0				$ 0		0	0	(31)
Other comprehensive income (loss) before reclassifications										0	0	31
Less: Amounts reclassified from AOCL										0	0	0
Less: Amounts reclassified for lower enacted corporate tax rate												0
Balance, end of year	$ 0				$ 0				$ 0	0	0	0
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications										(4,460)	(9,269)	(1,674)
Income tax (expense) benefit										938	1,946	586
Net income										(3,522)	(7,323)	(1,088)
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										3,637	(7,037)	(2,580)
Income tax (expense) benefit										(763)	1,477	903
Net income										2,874	(5,560)	(1,677)
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										(8,097)	(2,232)	906
Income tax (expense) benefit										1,701	469	(317)
Net income										$ (6,396)	$ (1,763)	$ 589

Benefit Plans - Components of N

Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Company Service Cost	$ 8,345	$ 10,530	$ 9,556
Interest Cost	15,705	15,095	15,475
Expected Return on Assets	(19,466)	(22,250)	(20,099)
Other Adjustments	0	0	0
Subtotal	4,584	3,375	4,932
Amortization of Net Transition Obligation/(Asset)	0	0	0
Amortization of Net Prior Service Cost/(Credit)	(281)	(351)	(426)
Amortization of Net Losses/(Gains)	8,412	6,937	6,169
Total Amortization	8,131	6,586	5,743
Net Periodic Benefit Cost	12,715	9,961	10,675
Cost of settlements	1,933	0	0
Total Expense for Year	14,648	9,961	10,675
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Company Service Cost	1,345	1,160	813
Interest Cost	1,130	834	706
Expected Return on Assets	(5,785)	(6,359)	(5,248)
Other Adjustments	0	0	0
Subtotal	(3,310)	(4,365)	(3,729)
Amortization of Net Transition Obligation/(Asset)	0	0	0
Amortization of Net Prior Service Cost/(Credit)	(34)	(4,104)	(6,649)
Amortization of Net Losses/(Gains)	0	(250)	0
Total Amortization	(34)	(4,354)	(6,649)
Net Periodic Benefit Cost	(3,344)	(8,719)	(10,378)
Cost of settlements	0	0	0
Total Expense for Year	$ (3,344)	$ (8,719)	$ (10,378)

Benefit Plans - Development of

Benefit Plans - Development of Funded Status (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation	$ 412,939	$ 375,562
Projected Benefit Obligation	(413,350)	(376,153)	$ (417,770)
Plan Assets at Fair Value	402,691	359,719	401,142
Funded Status - Overfunded/(Underfunded)	(10,659)	(16,434)
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation	27,496	28,085
Projected Benefit Obligation	(27,496)	(28,085)	(24,716)
Plan Assets at Fair Value	99,590	77,762	$ 85,303
Funded Status - Overfunded/(Underfunded)	$ 72,094	$ 49,677

Benefit Plans - Accumulated Oth

Benefit Plans - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain)/Loss	$ 99,826	$ 110,321
Net Prior Service Cost/(Credit)	(1,237)	(1,513)
Net Transition Obligation/(Asset)	0	0
Total at Year End	98,589	108,808	$ 108,054
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain)/Loss	(18,005)	939
Net Prior Service Cost/(Credit)	2,724	2,690
Net Transition Obligation/(Asset)	0	0
Total at Year End	$ (15,281)	$ 3,629	$ (15,576)

Benefit Plans - Change in Proje

Benefit Plans - Change in Project Benefit/Accumulated Benefit Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	$ 376,153	$ 417,770
Company Service Cost	8,345	10,530	$ 9,556
Interest Cost	15,705	15,095	15,475
Plan Participants' Contributions	0	0
Net Actuarial (Gain)/Loss due to Assumption Changes	43,302	(36,132)
Net Actuarial (Gain)/Loss due to Plan Experience	3,811	2,487
Benefit Payments from Fund	(30,829)	(32,674)
Benefit Payments Directly by Company	(3,105)	(908)
Plan Amendments	(5)	(15)
Other Adjustment	0	0
Settlement (Gain)Loss	(27)	0
Benefit Obligation at End of Year	413,350	376,153	417,770
Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	28,085	24,716
Company Service Cost	1,345	1,160	813
Interest Cost	1,130	834	706
Plan Participants' Contributions	382	475
Net Actuarial (Gain)/Loss due to Assumption Changes	(1,215)	(1,209)
Net Actuarial (Gain)/Loss due to Plan Experience	(860)	(692)
Benefit Payments from Fund	(826)	(1,077)
Benefit Payments Directly by Company	0	0
Plan Amendments	0	3,928
Other Adjustment	(545)	(50)
Settlement (Gain)Loss	0	0
Benefit Obligation at End of Year	$ 27,496	$ 28,085	$ 24,716

Benefit Plans - Change in Plan

Benefit Plans - Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
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	$ 359,719	$ 401,142
Company Contributions	10,205	10,908
Plan Participants' Contributions	0	0
Benefit Payments from Fund	(30,829)	(32,674)
Benefit Payments paid directly by Company	(3,105)	(908)
Actual Return on Assets	70,262	(19,583)
Other Adjustments	(3,561)	834
Fair Value of Plan Assets at End of Year	402,691	359,719
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	77,762	85,303
Company Contributions	0	0
Plan Participants' Contributions	382	475
Benefit Payments from Fund	(826)	(1,077)
Benefit Payments paid directly by Company	0	0
Actual Return on Assets	22,654	(6,464)
Other Adjustments	(382)	(475)
Fair Value of Plan Assets at End of Year	$ 99,590	$ 77,762

Benefit Plans - Change in Accum

Benefit Plans - Change in Accumulated Other Comprehensive Income (AOCI) and Expected Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension and Supplemental Executive Retirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI in Prior Year	$ 108,808	$ 108,054
Recognized during year - Prior Service (Cost)/Credit	281	351
Recognized during year - Net Actuarial (Losses)/Gains	(8,412)	(6,937)
Occurring during year - Prior Service Cost	(5)	(15)
Occurring during year - Net Actuarial Losses/(Gains)	(150)	7,355
Occuring during year - Net Settlement Losses/(Gains)	(1,933)	0
AOCI in Current Year	98,589	108,808
Amortization of Net Transition Obligation/(Asset)	0
Amortization of Prior Service Cost/(Credit)	(248)
Amortization of Net Losses/(Gains)	6,534
Other Postretirement Benefit Plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI in Prior Year	3,629	(15,576)
Recognized during year - Prior Service (Cost)/Credit	34	4,104
Recognized during year - Net Actuarial (Losses)/Gains	0	250
Occurring during year - Prior Service Cost	0	3,928
Occurring during year - Net Actuarial Losses/(Gains)	(18,944)	10,923
Occuring during year - Net Settlement Losses/(Gains)	0	0
AOCI in Current Year	(15,281)	$ 3,629
Amortization of Net Transition Obligation/(Asset)	0
Amortization of Prior Service Cost/(Credit)	51
Amortization of Net Losses/(Gains)	$ (761)

Benefit Plans - Actuarial Assum

Benefit Plans - Actuarial Assumptions and Year-End Asset Allocations (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Discount Rate (in hundredths)	3.45%	4.40%
Rate of Compensation Increase (in hundredths)	3.00%	3.00%
Discount Rate (in hundredths)	4.40%	3.75%
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)	3.20%	4.25%
Discount Rate (in hundredths)	4.25%	3.55%
Expected Long-term Return on Plan Assets (in hundredths)	7.50%	7.50%
Health Care Cost Trend Rate Assumed for Next Year (in hundredths)	6.00%	6.25%
Rate to Which the Cost Trend Rate is Assumed to Decline (Ultimate Trend Rate) (in hundredths)	5.00%	5.00%
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%	23.00%
Pension Plan \| Total fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocations of plans (in hundredths)	77.00%	77.00%

Benefit Plans - Fair Value of P

Benefit Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	$ 402,691	$ 359,719
Pension Plan \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	39,491	38,889
Pension Plan \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	363,200	320,830
Pension Plan \| Domestic Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	7,325	13,744
Pension Plan \| Domestic Mutual Funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	7,325	13,744
Pension Plan \| Domestic Mutual Funds \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	0
Pension Plan \| Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	203,684	181,363
Pension Plan \| Corporate Bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	0
Pension Plan \| Corporate Bonds \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	203,684	181,363
Pension Plan \| U.S. Government Securities
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	34,677	21,228
Pension Plan \| U.S. Government Securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	32,166	19,904
Pension Plan \| U.S. Government Securities \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	2,511	1,324
Pension Plan \| Municipal Bonds
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	38,998	43,424
Pension Plan \| Municipal Bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	0
Pension Plan \| Municipal Bonds \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	38,998	43,424
Pension Plan \| Foreign Bonds
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	34,024	30,113
Pension Plan \| Foreign Bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	0
Pension Plan \| Foreign Bonds \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	34,024	30,113
Pension Plan \| Exchange traded fund
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	5,241
Pension Plan \| Exchange traded fund \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	5,241
Pension Plan \| Exchange traded fund \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	0
Pension Plan \| Pooled Equity Accounts
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	83,983	64,606
Pension Plan \| Pooled Equity Accounts \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	0	0
Pension Plan \| Pooled Equity Accounts \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	83,983	64,606
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	99,590	77,762	$ 85,303
Other Postretirement Benefit Plan \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	99,590	77,762
Other Postretirement Benefit Plan \| Domestic Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	77,640	60,405
Other Postretirement Benefit Plan \| Domestic Mutual Funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	77,640	60,405
Other Postretirement Benefit Plan \| International Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	21,950	17,357
Other Postretirement Benefit Plan \| International Mutual Funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan Assets at Fair Value	$ 21,950	$ 17,357

Benefit Plans - Additional Disc

Benefit Plans - Additional Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
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	989
Expected Benefit Payments for the Year Ending: Current plus 1	1,600
Expected Benefit Payments for the Year Ending: Current plus 2	1,847
Expected Benefit Payments for the Year Ending: Current plus 3	2,087
Expected Benefit Payments for the Year Ending: Current plus 4	2,254
Expected Benefit Payments for the Year Ending: Current plus 5	2,367
Expected Benefit Payments for the Year Ending: Current plus 6 - 10	11,874
Effect of 1-percentage point increase on total service and interest cost component	380
Effect of 1-percentage point decrease on total service and interest cost components	(328)
Effect of 1-percentage point increase on postretirement benefit obligation	2,528
Effect of 1-percentage point decrease on postretirement benefit obligation	$ (2,239)
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	$ 10,205	$ 10,908
Current plus 1	12,350
Actual Benefit Payments for the Year Ending: Current	33,934
Expected Benefit Payments for the Year Ending: Current plus 1	34,943
Expected Benefit Payments for the Year Ending: Current plus 2	31,008
Expected Benefit Payments for the Year Ending: Current plus 3	30,981
Expected Benefit Payments for the Year Ending: Current plus 4	31,175
Expected Benefit Payments for the Year Ending: Current plus 5	30,547
Expected Benefit Payments for the Year Ending: Current plus 6 - 10	$ 141,768

Benefit Plans - Narrative (Deta

Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
Benefit Plans - Narrative (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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' contributions (in hundredths)	100.00%
Employee contributions subject to employer match (in hundredths)	4.00%
Profit sharing and 401(k) savings plan expenses	$ 7,400,000	$ 6,000,000	$ 6,000,000
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Lump sum pension plan benefit payments	$ 18,500,000	$ 20,900,000
Pension Plan \| Equity securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	40.00%
Other Postretirement Benefit Plan \| Equity securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations (in hundredths)	100.00%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net deferred tax assets and liabilities [Abstract]
Total deferred tax assets	$ 63,533				$ 83,082				$ 63,533	$ 83,082
Total deferred tax liabilities	(57,791)				(13,898)				(57,791)	(13,898)
Net deferred tax asset	5,742				69,184				5,742	69,184
Components of net deferred tax asset [Abstract]
Unearned premium reserves	30,487				31,808				30,487	31,808
Benefit plans	(10,790)				(5,047)				(10,790)	(5,047)
Loss reserves	2,175				3,113				2,175	3,113
Unrealized (appreciation) depreciation in investments	(36,822)				9,407				(36,822)	9,407
Mortgage investments	8,359				8,307				8,359	8,307
Deferred compensation	9,270				8,662				9,270	8,662
AMT credit carryforward	8,303				17,521				8,303	17,521
Other, net	(5,240)				(4,587)				(5,240)	(4,587)
Components of provisions for (benefit from) income taxes [Abstract]
Current Federal									162,911	(16,272)	$ 73,348
Deferred Federal									11,860	185,598	351,677
Other									(557)	4,727	3,710
Provision for income taxes	45,599	$ 46,186	$ 43,433	$ 38,996	36,963	$ 49,994	$ 50,708	$ 36,388	174,214	174,053	428,735
Income tax expense due to remeasurement of net deferred tax assets											133,000
Income taxes paid									158,300	$ 12,200	$ 22,000
Amount of tax and loss bonds held	176,000								$ 176,000
Reconciliation of effective income tax rate [Abstract]
Federal statutory income tax rate (in hundredths)									21.00%	21.00%	35.00%
Additional income tax provision (benefit) related to the rate decrease included in the Tax Act (in hundredths)									0	0	0.170
Additional income tax provision related to IRS litigation (in hundredths)									0.00%	(0.30%)	3.70%
Tax exempt municipal bond interest (in hundredths)									(0.60%)	(0.70%)	(1.40%)
Other, net (in hundredths)									0.10%	0.60%	0.40%
Effective income tax provision rate (in hundredths)									20.50%	20.60%	54.70%
Unrecognized tax benefits [Roll Forward]
Balance at beginning of year				$ 0				$ 142,821	$ 0	$ 142,821	$ 108,245
Additions for tax positions of prior years										0	35,003
Reductions for tax positions of prior years										(3,070)	(427)
Settlements										(139,751)	0
Balance at end of year	$ 0				$ 0				$ 0	0	$ 142,821
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)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions	Jan. 28, 2020	Nov. 30, 2019	Sep. 30, 2019	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Cumulative effect to reclassify certain tax effects from accumulated other comprehensive loss							$ (10,422,000)
Shares repurchased during period (in shares)					8.7	16
Shares repurchased, weighted average price per share (in dollars per share)					$ 13.13	$ 10.95
Remaining authorized repurchase amount					$ 111,000,000	$ 25,000,000
Common stock, dividends, per share, cash paid (in dollars per share)		$ 0.06	$ 0.06
Payments of ordinary dividends, common stock					$ 41,914,000	$ 0	$ 0
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				$ 202,500,000			$ 202,500,000
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
Accumulated other comprehensive loss
Debt Instrument [Line Items]
Cumulative effect to reclassify certain tax effects from accumulated other comprehensive loss				(10,400,000)			$ (10,422,000)
Retained earnings
Debt Instrument [Line Items]
Cumulative effect to reclassify certain tax effects from accumulated other comprehensive loss				$ 10,400,000			$ 10,422,000
Subsequent Event
Debt Instrument [Line Items]
Stock repurchase program, authorized amount	$ 300,000,000
Common stock, dividends, per share, declared (in dollars per share)	$ 0.06

Statutory Information (Details)

Statutory Information (Details)	3 Months Ended	12 Months Ended
Statutory Information (Details)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)jurisdiction	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Statutory capital requirements [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%
Statutory net income			$ 305,857,000	$ 375,484,000	$ 310,776,000
Statutory policyholders' surplus			1,619,069,000	1,683,058,000	1,622,115,000
Contingency reserve			$ 3,021,055,000	2,442,996,000	1,896,701,000
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			9.6 to 1
Risk-to-capital ratio on combined insurance operations			9.6
Maximum
Statutory capital requirements [Abstract]
Risk to capital ratio			25
Mortgage Guaranty Insurance Corporation
Statutory capital requirements [Abstract]
Loss ratio			12.00%
Statutory net income			$ 273,000,000
Statutory policyholders' surplus			1,619,000,000
Dividends paid to the parent company			$ 280,000,000	$ 220,000,000	$ 140,000,000
Risk to capital ratio			9.7
Risk to capital ratio at end of period			9.7 to 1
Amount of policyholders position above or below required MPP			$ 3,000,000,000
Amount of required MPP			1,700,000,000
Reduction in statutory net income due to increase in contingency reserve			$ 556,000,000
Forecast \| Mortgage Guaranty Insurance Corporation
Statutory capital requirements [Abstract]
Dividends paid to the parent company	$ 70,000,000	$ 280,000,000
Special dividend paid	$ 320,000,000
Insurance Subsidiaries
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

Share-based Compensation Plan_2

Share-based Compensation Plans (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 18.9	$ 20.9	$ 14.9
Income tax benefit from compensation cost	$ 2.7	$ 3	$ 5.2
Shares [Roll Forward]
Restricted stock outstanding at end of period (in shares)	4,200,000
Restricted Stock/Restricted Stock Units
Weighted average grant date fair market value [Abstract]
Restricted stock outstanding at end of period (in dollars per share)	$ 12.27
Granted (in dollars per share)	11.92	$ 15.69	$ 10.41
Vested (in dollars per share)	9.37
Forfeited (in dollars per share)	13.67
Restricted stock outstanding at end of period (in dollars per share)	$ 12.81	$ 12.27
Shares [Roll Forward]
Restricted stock outstanding at beginning of period (in shares)	3,583,506
Granted (in shares)	2,002,500
Vested (in shares)	(1,067,890)
Forfeited (in shares)	(367,722)
Restricted stock outstanding at end of period (in shares)	4,150,394	3,583,506
Additional disclosures [Abstract]
Restricted stock, performance shares (in shares)	3,200,000
Restricted stock, time vested shares (in shares)	1,000,000
Total fair value of restricted stock vested	$ 13.7	$ 19.1	$ 15.3
Unrecognized compensation cost	30.7
Unrecognized compensation cost, performance shares	20.2
Unrecognized compensation cost, time vested shares	$ 10.5
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)	3,400,000
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)

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Remaining term of operating leases (in years)	4 years
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 1,204
2021	588
2022	380
2023	83
2024 and thereafter	0
Total	2,255
Minimum future operating lease payments [Abstract]
2019		$ 1,406
2020		1,069
2021		371
2022		161
2023 and thereafter		0
Total		3,007
Operating lease, expense	$ 2,100
Total rental expense under operating leases		$ 1,900	$ 2,000

Litigation and Contingencies (D

Litigation and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Average paid claim reduction due to curtailments (in hundredths)	5.00%	5.80%
Loss contingency, estimate of possible loss	$ 23.5
Maximum exposure to loss	$ 46

Unaudited Quarterly Financial_3

Unaudited Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net premiums earned	$ 266,267	$ 267,857	$ 247,102	$ 249,762	$ 245,665	$ 250,426	$ 246,964	$ 232,107	$ 1,030,988	$ 975,162	$ 934,747
Investment income, net of expenses	41,322	42,715	42,423	40,585	38,328	36,380	34,502	32,121	167,045	141,331	120,871
Realized (losses) gains	1,320	4,205	307	(526)	(241)	1,114	(1,897)	(329)	5,306	(1,353)	231
Other revenue	2,717	3,606	2,485	1,830	1,881	2,525	2,431	1,871	10,638	8,708	10,205
Loss incurred, net	23,690	33,985	21,836	39,064	27,685	(1,518)	(13,455)	23,850	118,575	36,562	53,709
Underwriting and other expenses, net	65,227	61,278	59,270	61,650	63,239	60,069	57,933	61,895	247,425	243,136
Loss on debt extinguishment									0	0	65
Provision for income tax	45,599	46,186	43,433	38,996	36,963	49,994	50,708	36,388	174,214	174,053	428,735
Net income	$ 177,110	$ 176,934	$ 167,778	$ 151,941	$ 157,746	$ 181,900	$ 186,814	$ 143,637	$ 673,763	$ 670,097	$ 355,761
Earnings per Share [Abstract]
Basic (in dollars per share)	$ 0.51	$ 0.50	$ 0.47	$ 0.43	$ 0.44	$ 0.50	$ 0.51	$ 0.39	$ 1.91	$ 1.83	$ 0.98
Diluted (in dollars per share)	$ 0.49	$ 0.49	$ 0.46	$ 0.42	$ 0.43	$ 0.49	$ 0.49	$ 0.38	$ 1.85	$ 1.78	$ 0.95

SCHEDULE I - SUMMARY OF INVES_2

SCHEDULE I - SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES (Details) $ in Thousands	Dec. 31, 2019USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	$ 5,579,738
Fair Value	5,755,220
Amount at which shown in the balance sheet	5,755,220
Fixed income
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	5,562,550
Fair Value	5,737,892
Amount at which shown in the balance sheet	5,737,892
Fixed income \| U.S. Treasury securities and obligations of U.S. government corporations and agencies
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	195,176
Fair Value	196,203
Amount at which shown in the balance sheet	196,203
Fixed income \| Obligations of U.S. states and political subdivisions
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	1,555,394
Fair Value	1,653,865
Amount at which shown in the balance sheet	1,653,865
Fixed income \| Public utilities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	270,675
Fair Value	278,991
Amount at which shown in the balance sheet	278,991
Fixed income \| ABS
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	227,376
Fair Value	229,664
Amount at which shown in the balance sheet	229,664
Fixed income \| Collateralized loan obligations
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	327,076
Fair Value	325,466
Amount at which shown in the balance sheet	325,466
Fixed income \| Mortgage-backed
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	545,618
Fair Value	547,572
Amount at which shown in the balance sheet	547,572
Fixed income \| All other corporate bonds
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	2,441,235
Fair Value	2,506,131
Amount at which shown in the balance sheet	2,506,131
Equity Securities
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	17,188
Fair Value	17,328
Amount at which shown in the balance sheet	17,328
Equity Securities \| Industrial, miscellaneous and all other
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Amortized Cost	17,188
Fair Value	17,328
Amount at which shown in the balance sheet	$ 17,328

SCHEDULE II - CONDENSED FINAN_2

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Fixed income, available-for-sale, at fair value (amortized cost, 2019 – $287,489; 2018 – $203,743)	$ 5,737,892				$ 5,151,987				$ 5,737,892	$ 5,151,987
Cash and cash equivalents	161,847				151,892				161,847	151,892
Accrued investment income	49,705				48,001				49,705	48,001
Other assets	99,347				85,572				99,347	85,572
Total assets	6,229,571				5,677,802				6,229,571	5,677,802
Liabilities:
Senior notes	420,867				419,713				420,867	419,713
Convertible junior subordinated debentures	256,872				256,872				256,872	256,872
Other liabilities	151,962				180,322				151,962	180,322
Total liabilities	1,920,337				2,095,911				1,920,337	2,095,911
Shareholders’ equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2019 - 371,353; 2018 - 371,353; outstanding 2019 - 347,308; 2018 - 355,371)	371,353				371,353				371,353	371,353
Paid-in capital	1,869,719				1,862,536				1,869,719	1,862,536
Treasury stock (shares at cost 2019 – 24,045; 2018 – 15,982)	(283,196)				(175,059)				(283,196)	(175,059)
Accumulated other comprehensive income (loss), net of tax	72,708				(124,214)				72,708	(124,214)
Retained earnings	2,278,650				1,647,275				2,278,650	1,647,275
Total shareholders' equity	4,309,234				3,581,891				4,309,234	3,581,891	$ 3,154,526
Total liabilities and shareholders' equity	6,229,571				5,677,802				6,229,571	5,677,802
Parenthetical information [Abstract]
Fixed income, amortized cost	$ 5,562,550				$ 5,196,784				$ 5,562,550	$ 5,196,784
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				371,353,000				371,353,000	371,353,000
Common stock, shares outstanding (in shares)	347,308,000				355,371,000				347,308,000	355,371,000
Treasury stock, shares at cost (in shares)	24,045,000				15,982,000				24,045,000	15,982,000
Revenues:
Investment income, net of expenses	$ 41,322	$ 42,715	$ 42,423	$ 40,585	$ 38,328	$ 36,380	$ 34,502	$ 32,121	$ 167,045	$ 141,331	120,871
Realized (losses) gains	1,320	4,205	307	(526)	(241)	1,114	(1,897)	(329)	5,306	(1,353)	231
Total revenues									1,213,977	1,123,848	1,066,054
Expenses:
Interest expense									52,656	52,993	57,035
Loss on debt extinguishment									0	0	65
Total losses and expenses									366,000	279,698	281,558
Income before tax									847,977	844,150	784,496
Provision for income taxes	45,599	46,186	43,433	38,996	36,963	49,994	50,708	36,388	174,214	174,053	428,735
Net income	177,110	176,934	167,778	151,941	157,746	181,900	186,814	143,637	673,763	670,097	355,761
Other comprehensive income (loss), net of tax									196,922	(80,413)	41,739
Comprehensive income									870,685	589,684	397,500
Cash flows from operating activities:
Net income	177,110	$ 176,934	$ 167,778	151,941	157,746	$ 181,900	$ 186,814	143,637	673,763	670,097	355,761
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred Federal									11,860	185,598	351,677
Loss on debt extinguishment									0	0	65
Change in certain assets and liabilities:
Accrued investment income									(1,704)	(1,941)	(1,987)
Net cash provided by operating activities									609,532	544,517	406,657
Cash flows from investing activities:
Net cash used in investing activities									(422,108)	(317,780)	(303,641)
Cash flows from financing activities:
Proceeds from revolving credit facility									0	0	150,000
Repayment of revolving credit facility									0	0	(150,000)
Purchase or repayment of convertible senior notes									0	0	(145,620)
Repurchase of common stock									(125,766)	(163,419)	0
Dividends paid									(41,914)	0	0
Payment of debt issuance costs									0	0	(1,630)
Payment of withholding taxes related to share-based compensation net share settlement									(5,726)	(8,131)	(6,821)
Net cash used in financing activities									(173,406)	(171,550)	(158,575)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents									14,018	55,187	(55,559)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year				155,038				99,851	155,038	99,851	155,410
Cash and cash equivalents and restricted cash and cash equivalents at end of year	169,056				155,038				169,056	155,038	99,851
Parent Company
Assets
Fixed income, available-for-sale, at fair value (amortized cost, 2019 – $287,489; 2018 – $203,743)	288,362				201,507				288,362	201,507
Cash and cash equivalents	36,621				46,502				36,621	46,502
Investment in subsidiaries, at equity in net assets	4,611,356				3,981,970				4,611,356	3,981,970
Accounts receivable - affiliates	2,129				1,396				2,129	1,396
Income taxes - current and deferred	196,978				186,561				196,978	186,561
Accrued investment income	2,498				2,020				2,498	2,020
Other assets	81				740				81	740
Total assets	5,138,025				4,420,696				5,138,025	4,420,696
Liabilities:
Senior notes	420,867				419,713				420,867	419,713
Convertible junior subordinated debentures	389,522				389,522				389,522	389,522
Accrued interest	17,928				17,930				17,928	17,930
Other liabilities	474				11,640				474	11,640
Total liabilities	828,791				838,805				828,791	838,805
Shareholders’ equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2019 - 371,353; 2018 - 371,353; outstanding 2019 - 347,308; 2018 - 355,371)	371,353				371,353				371,353	371,353
Paid-in capital	1,869,719				1,862,536				1,869,719	1,862,536
Treasury stock (shares at cost 2019 – 24,045; 2018 – 15,982)	(283,196)				(175,059)				(283,196)	(175,059)
Accumulated other comprehensive income (loss), net of tax	72,708				(124,214)				72,708	(124,214)
Retained earnings	2,278,650				1,647,275				2,278,650	1,647,275
Total shareholders' equity	4,309,234				3,581,891				4,309,234	3,581,891
Total liabilities and shareholders' equity	5,138,025				4,420,696				5,138,025	4,420,696
Parenthetical information [Abstract]
Fixed income, amortized cost	$ 287,489				$ 203,743				$ 287,489	$ 203,743
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				371,353,000				371,353,000	371,353,000
Common stock, shares outstanding (in shares)	347,308,000				355,371,000				347,308,000	355,371,000
Treasury stock, shares at cost (in shares)	24,045,000				15,982,000				24,045,000	15,982,000
Revenues:
Investment income, net of expenses									$ 7,695	$ 4,685	3,177
Realized (losses) gains									(311)	(532)	(13)
Total revenues									7,384	4,153	3,164
Expenses:
Operating expenses									793	637	642
Interest expense									61,593	61,930	65,972
Loss on debt extinguishment									0	0	65
Total losses and expenses									62,386	62,567	66,679
Income before tax									(55,002)	(58,414)	(63,515)
Provision for income taxes									(12,263)	(13,517)	95,517
Equity in net income of subsidiaries									716,502	714,994	514,793
Net income									673,763	670,097	355,761
Other comprehensive income (loss), net of tax									196,922	(80,413)	41,739
Comprehensive income									870,685	589,684	397,500
Cash flows from operating activities:
Net income									673,763	670,097	355,761
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of subsidiaries									(716,502)	(714,994)	(514,793)
Dividends received from subsidiaries									154,413	199,692	110,145
Deferred Federal									(10,416)	(11,756)	96,741
Loss on debt extinguishment									0	0	65
Other									21,104	24,303	18,716
Change in certain assets and liabilities:
Accounts receivable - affiliates									(735)	18	(634)
Income taxes receivable									1	17,859	297
Accrued investment income									(478)	112	(192)
Accrued interest									(2)	(4)	(2,819)
Net cash provided by operating activities									121,148	185,327	63,287
Cash flows from investing activities:
Purchases of investments									(117,663)	(83,003)	(97,091)
Proceeds from sales of investments									160,040	93,481	176,960
Net cash used in investing activities									42,377	10,478	79,869
Cash flows from financing activities:
Proceeds from revolving credit facility									0	0	150,000
Repayment of revolving credit facility									0	0	(150,000)
Purchase or repayment of convertible senior notes									0	0	(150,124)
Repurchase of common stock									(125,766)	(163,419)	0
Dividends paid									(41,914)	0	0
Payment of debt issuance costs									0	0	(1,630)
Payment of withholding taxes related to share-based compensation net share settlement									(5,726)	(8,131)	(6,821)
Net cash used in financing activities									(173,406)	(171,550)	(158,575)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents									(9,881)	24,255	(15,419)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year				$ 46,502				$ 22,247	46,502	22,247	37,666
Cash and cash equivalents and restricted cash and cash equivalents at end of year	$ 36,621				$ 46,502				$ 36,621	$ 46,502	$ 22,247

SCHEDULE II - CONDENSED FINAN_3

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - SUPPLEMENTARY NOTES (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Insurance Subsidiaries
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [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
Proceeds from contribution from parent			$ 0	$ 0	$ 0
Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Stated interest rate (in hundredths)			9.00%
Mortgage Guaranty Insurance Corporation
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Dividends paid to the parent company			$ 280,000,000	$ 220,000,000	$ 140,000,000
Mortgage Guaranty Insurance Corporation \| Convertible Junior Subordinated Debentures, at 9% per annum, Due 2063
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Investment in holding company debt			$ 132,700,000
Forecast \| Mortgage Guaranty Insurance Corporation
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Dividends paid to the parent company	$ 70,000,000	$ 280,000,000
Special dividend paid	$ 320,000,000

SCHEDULE IV - REINSURANCE (Deta

SCHEDULE IV - REINSURANCE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Gross Amount	$ 1,155,240	$ 1,084,748	$ 1,059,973
Ceded to Other Companies	129,337	111,391	125,735
Assumed From Other Companies	5,085	1,805	509
Net Amount	$ 1,030,988	$ 975,162	$ 934,747
Percentage of Amount Assumed to Net	0.50%	0.20%	0.10%