MGIC Investment (MTG) 10-Q 6 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 29, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	MGIC INVESTMENT CORP
Entity Central Index Key	876,437
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		340,636,237
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Securities, available-for-sale, at fair value:
Fixed maturities (amortized cost, 2016 - $4,506,178; 2015 - $4,684,148)	$ 4,557,914	$ 4,657,561
Equity securities	6,289	5,645
Total investment portfolio	4,564,203	4,663,206
Cash and cash equivalents	249,898	181,120
Accrued investment income	39,019	40,224
Reinsurance recoverable on loss reserves	41,119	44,487
Reinsurance recoverable on paid losses	3,855	3,319
Premiums receivable	47,185	48,469
Home office and equipment, net	31,047	30,095
Deferred insurance policy acquisition costs	15,946	15,241
Deferred income taxes, net	702,400	762,080
Other assets	78,731	80,102
Total assets	5,773,403	5,868,343
Liabilities:
Loss reserves	1,753,389	1,893,402
Unearned premiums	289,879	279,973
Federal Home Loan Bank advance	155,000	0
Convertible senior notes	685,624	822,301
Convertible junior subordinated debentures	256,872	389,522
Other liabilities	289,240	247,005
Total liabilities	$ 3,430,004	$ 3,632,203
Contingencies
Shareholders' equity:
Common stock (one dollar par value, shares authorized 1,000,000; shares issued 2016 - 341,076; 2015 - 340,097; shares outstanding 2016 - 340,636; 2015 - 339,657)	$ 341,076	$ 340,097
Paid-in capital	1,657,783	1,670,238
Treasury stock at cost (shares - 440)	(3,362)	(3,362)
Accumulated other comprehensive loss, net of tax	(11,336)	(60,880)
Retained earnings	359,238	290,047
Total shareholders’ equity	2,343,399	2,236,140
Total liabilities and shareholders’ equity	$ 5,773,403	$ 5,868,343

CONSOLIDATED BALANCE SHEETS (U3

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 4,506,178	$ 4,684,148
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)	341,076,000	340,097,000
Common stock, shares outstanding (in shares)	340,636,000	339,657,000
Treasury stock, shares at cost (in shares)	440,000	440,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Premiums written:
Direct	$ 265,291	$ 265,412
Assumed	208	338
Ceded	(34,218)	(31,294)
Net premiums written	231,281	234,456
Increase in unearned premiums, net	(9,940)	(17,168)
Net premiums earned	221,341	217,288
Investment income, net of expenses	27,809	24,120
Net realized investment gains (losses):
Total other-than-temporary impairment losses	0	0
Portion of losses recognized in comprehensive income, before taxes	0	0
Net impairment losses recognized in earnings	0	0
Other realized investment gains	3,056	26,327
Net realized investment gains	3,056	26,327
Other revenue	6,373	2,480
Total revenues	258,579	270,215
Losses and expenses:
Losses incurred, net	85,012	81,785
Change in premium deficiency reserve	0	(6,418)
Amortization of deferred policy acquisition costs	1,961	1,757
Other underwriting and operating expenses, net	39,777	39,268
Interest expense	14,701	17,362
Loss on debt extinguishment	13,440	0
Total losses and expenses	154,891	133,754
Income before tax	103,688	136,461
Provision for income taxes	34,497	3,385
Net income	$ 69,191	$ 133,076
Income per share
Basic (in dollars per share)	$ 0.20	$ 0.39
Diluted (in dollars per share)	$ 0.17	$ 0.32
Weighted average shares outstanding - basic and diluted
Weighted average common shares outstanding - basic (in shares)	340,144	339,107
Weighted average common shares outstanding - diluted (in shares)	431,365	468,121

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 69,191	$ 133,076
Other comprehensive income (loss), net of tax:
Change in unrealized investment gains and losses	50,827	19,563
Benefit plan adjustments	(308)	(700)
Foreign currency translation adjustment	(975)	(2,014)
Other comprehensive income (loss), net of tax	49,544	16,849
Comprehensive income	$ 118,735	$ 149,925

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Paid-in capital	Treasury stock	Accumulated other comprehensive income (loss)	Retained earnings (deficit)
Balance, beginning of period at Dec. 31, 2014		$ 340,047	$ 1,663,592	$ (32,937)	$ (81,341)	$ (852,458)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net common stock issued under share-based compensation plans		32	38
Reissuance of treasury stock, net			(7,251)	29,575		(29,494)
Tax benefit from share-based compensation			2,568
Equity compensation			3,264
Reacquisition of convertible junior subordinated debentures-equity component			0
Other comprehensive income	$ 16,849				16,849
Net income	133,076					133,076
Balance, end of period at Mar. 31, 2015	1,185,560	340,079	1,662,211	(3,362)	(64,492)	(748,876)
Balance, beginning of period at Dec. 31, 2015	2,236,140	340,097	1,670,238	(3,362)	(60,880)	290,047
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net common stock issued under share-based compensation plans		979	(5,949)
Reissuance of treasury stock, net			0	0		0
Tax benefit from share-based compensation			115
Equity compensation			3,129
Reacquisition of convertible junior subordinated debentures-equity component			(9,750)
Other comprehensive income	49,544				49,544
Net income	69,191					69,191
Balance, end of period at Mar. 31, 2016	$ 2,343,399	$ 341,076	$ 1,657,783	$ (3,362)	$ (11,336)	$ 359,238

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income	$ 69,191	$ 133,076
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	14,109	11,311
Deferred tax expense (benefit)	33,270	(11)
Realized investment gains, net	(3,056)	(26,327)
Excess tax benefits related to share-based compensation	(115)	(2,568)
Payment of original issue discount-convertible junior subordinated debentures	(41,540)	0
Change in certain assets and liabilities:
Accrued investment income	1,205	(1,596)
Prepaid insurance premium	34	(2,496)
Reinsurance recoverable on loss reserves	3,368	2,426
Reinsurance recoverable on paid losses	(536)	458
Premium receivable	1,284	(1,812)
Deferred insurance policy acquisition costs	(705)	(1,011)
Profit commission receivable	760	(23,474)
Loss reserves	(140,013)	(152,183)
Premium deficiency reserve	0	(6,418)
Unearned premiums	9,906	19,639
Return premium accrual	(4,850)	3,300
Income taxes payable - current	289	287
Other	869	14,691
Net cash used in operating activities	(56,530)	(32,708)
Purchases of investments:
Fixed maturities	(288,273)	(940,867)
Equity securities	(3,109)	(18)
Proceeds from sales of fixed maturities	315,927	795,968
Proceeds from maturity of fixed maturities	139,863	192,463
Proceeds from sale of equity securities	2,525	0
Net increase in payable for securities	44,289	699
Net decrease in restricted cash	0	17,212
Additions to property and equipment	(1,916)	(576)
Net cash provided by investing activities	209,306	64,881
Cash flows from financing activities:
Proceeds from issuance of long-term debt	155,000	0
Purchase of convertible senior notes	(138,253)	0
Purchase of convertible junior subordinated debentures-liability component	(91,110)	0
Purchase of convertible junior subordinated debentures-equity component	(9,750)	0
Excess tax benefits related to share-based compensation	115	2,568
Net cash (used in) provided by financing activities	(83,998)	2,568
Net increase in cash and cash equivalents	68,778	34,741
Cash and cash equivalents at beginning of period	181,120	197,882
Cash and cash equivalents at end of period	$ 249,898	$ 232,623

Nature of Business and Basis of

Nature of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Nature of Business and Basis of Presentation 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. The accompanying unaudited consolidated financial statements of MGIC Investment Corporation and its wholly-owned subsidiaries have been prepared in accordance with the instructions to Form 10-Q as prescribed by the Securities and Exchange Commission (“SEC”) for interim reporting and do not include all of the other information and disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). These statements should be read in conjunction with the consolidated financial statements and notes thereto for the year ended December 31, 2015 included in our Annual Report on Form 10-K. As used below, “we,” “our” and “us” refer to MGIC Investment Corporation’s consolidated operations or to MGIC Investment Corporation, as the context requires. In the opinion of management the accompanying financial statements include all adjustments, consisting primarily of normal recurring accruals, necessary to fairly state our consolidated financial position and consolidated results of operations for the periods indicated. The consolidated results of operations for the interim period may not be indicative of the results that may be expected for the year ending December 31, 2016 . Reclassifications Certain reclassifications have been made in the accompanying financial statements to 2015 amounts to conform to 2016 presentation. See Note 2 - “New Accounting Pronouncements” for a discussion of our adoption of accounting guidance related to the presentation of debt issuance costs in the first quarter of 2016, with retrospective application to prior periods. Subsequent events We have considered subsequent events through the date of this filing.

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements Adopted Accounting Standards Presentation of Debt Issuance Costs In April 2015, the Financial Accounting Standards Board (“FASB”) issued updated guidance related to the presentation of debt issuance costs. The new standard requires the presentation of debt issuance costs in the balance sheet as a deduction from the carrying amount of the related debt liability instead of a deferred charge, consistent with the treatment of debt discounts. The updated guidance was effective for reporting periods beginning after December 15, 2015. The adoption of this guidance as of March 31, 2016 has been applied retrospectively to prior periods. See Note 3 - “Debt” for the reclassification made to our consolidated balance sheet as of December 31, 2015. The adoption of this guidance had no impact on our statements of operations or retained earnings. Accounting for Share-Based Compensation When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period In June 2014, the FASB issued updated guidance to resolve diversity in practice concerning employee shared-based compensation that contains performance targets that could be achieved after the requisite service period. No explicit guidance on how to account for these types of performance share-based compensation awards existed prior to this update. The updated guidance requires that a performance target that affects vesting and that can be achieved after the requisite service period be treated as a performance condition. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which service has been rendered. If the performance target becomes probable of being achieved before the end of the service period, the remaining unrecognized compensation cost for which requisite service has not yet been rendered is recognized prospectively over the remaining service period. The total amount of compensation cost recognized during and after the service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The updated guidance was effective for reporting periods after December 15, 2015. The adoption of this guidance as of March 31, 2016, with application to awards granted during the first quarter of 2016, is not expected to have a material impact on our consolidated financial statements. Prospective Accounting Standards Improvements to Employee Share-Based Compensation Accounting In March 2016, the FASB issued updated guidance that simplifies several aspects of the accounting for employee share-based compensation including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. The updated guidance requires that, prospectively, all tax effects related to share-based compensation be made through the statement of operations at the time of settlement as opposed to excess tax benefits being recognized in paid-in capital under the current guidance. The updated guidance also removes the requirement to delay recognition of a tax benefit until it reduces current taxes payable. This change is required to be applied on a modified retrospective basis, with a cumulative effect adjustment to opening retained earnings. Additionally, all tax related cash flows resulting from share-based compensation are to be reported as operating activities on the statement of cash flows, a change from the existing requirement to present tax benefits as an inflow from financing activities and an outflow from operating activities. Finally, for tax withholding purposes, entities will be allowed to withhold an amount of shares up to the employee’s maximum individual tax rate (as opposed to the minimum statutory tax rate) in the relevant jurisdiction without resulting in liability classification of the award. The change in withholding requirements will be applied on a modified retrospective approach. The updated guidance is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted in any interim or annual period. We are currently evaluating the impacts the adoption of this guidance will have on our consolidated financial statements. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued updated guidance to address the recognition, measurement, presentation, and disclosure of certain financial instruments. The updated guidance requires equity investments, except those accounted for under the equity method of accounting, that have a readily determinable fair value to be measured at fair value with changes in fair value recognized in net income. Equity investments that do not have readily determinable fair values may be remeasured at fair value either upon the occurrence of an observable price change or upon identification of an impairment. A qualitative assessment for impairment is required for equity investments without readily determinable fair values. The updated guidance also eliminates the requirement to disclose the method and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost on the balance sheet. The updated guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods and will require recognition of a cumulative effect adjustment at adoption. We do not currently expect the adoption of this guidance to impact our consolidated financial position or liquidity. Disclosures about Short-Duration Contracts In May 2015, the FASB issued updated guidance requiring expanded disclosures for insurance entities that issue short-duration contracts. The expanded disclosures are designed to provide additional insight into an insurance entity’s ability to underwrite and anticipate costs associated with claims. The disclosures include information about incurred and paid claims development, on a net of reinsurance basis, for the number of years claims incurred typically remain outstanding, not to exceed ten years. Each period presented in the disclosure about claims development that precedes the current reporting periods is considered supplementary information. The expanded disclosures also include more transparent information about significant changes in methodologies and assumptions used to estimate claims, and the timing, frequency, and severity of claims. The disclosures required by this update are effective for annual periods beginning after December 31, 2015, and interim periods within annual periods beginning after December 31, 2016, and is to be applied retrospectively. We are evaluating the applicability and impact, if any, of the new disclosure requirements.

Debt

Debt	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Debt	Debt 2016 debt transactions During the first quarter of 2016, market conditions allowed us to complete a series of transactions that repositioned the maturity profile of our debt and lowered our interest expense. These transactions, including the amounts and accounting impacts, are discussed below. 5% Convertible Senior Notes During the first quarter of 2016, we purchased $138.3 million in par value of our 5% Convertible Senior Notes (the “5% Notes”) due in 2017 at a purchase price of $143.4 million , plus accrued interest using funds held at our holding company. The excess of the purchase price over par value is reflected as a loss on debt extinguishment and outstanding debt issuance costs on the purchased debt were recognized as interest expense on our consolidated statement of operations for the three months ended March 31, 2016 . The purchases of the 5% Notes reduced our potentially dilutive shares by approximately 10.3 million shares. 9% Convertible Junior Subordinated Debentures In February 2016, MGIC purchased $132.7 million of par value of our 9% Convertible Junior Subordinated Debentures (the “9% Debentures”) due in 2063 at a purchase price of $150.7 million , plus accrued interest. The 9% Debentures include a conversion feature that allows us, at our option, to make a cash payment to converting holders in lieu of issuing shares of common stock upon conversion of the 9% Debentures. The accounting standards applicable to extinguishment of debt with a cash conversion feature require the consideration paid to be allocated between the extinguishment of the liability component and reacquisition of the equity component. The purchase of the 9% Debentures resulted in an $8.3 million loss on debt extinguishment on the consolidated statement of operations for the three months ended March 31, 2016 , which represents the difference between the fair value and the carrying value of the liability component on the purchase date. In addition, our shareholders’ equity was separately reduced by $9.8 million related to the reacquisition of the equity component. For GAAP accounting purposes, the 9% Debentures owned by MGIC are considered retired and are eliminated in our consolidated financial statements and the underlying common stock equivalents, approximately 9.8 million shares, are not included in the computation of diluted shares. Federal Home Loan Bank Advance In February 2016, MGIC borrowed $155.0 million in the form of a fixed rate advance from the Federal Home Loan Bank (“FHLB”) (the “Advance”) to provide funds used to purchase the 9% Debentures. 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. Accounting standard update As of March 31, 2016 we adopted the accounting update related to the presentation of debt issuance costs in the financial statements. The change in accounting guidance has been applied retrospectively to prior periods. As a result, a reclassification of approximately $11.2 million of debt issuance costs was made on our December 31, 2015 balance sheet, resulting in a reduction to other assets and a reduction to long-term debt; there was no impact on our consolidated statement of operations or retained earnings. The impact of the reclassification of debt issuance costs on our outstanding debt obligations as of December 31, 2015 is as follows. December 31, 2015 (In millions) As previously reported Adjustment As Adjusted Convertible Senior Notes, interest at 5% per annum, due May 2017 $ 333.5 $ (2.0 ) $ 331.5 Convertible Senior Notes, interest at 2% per annum, due April 2020 500.0 (9.2 ) 490.8 Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063 389.5 — 389.5 Total long-term debt $ 1,223.0 $ (11.2 ) $ 1,211.8 The carrying amount of our debt obligations as of March 31, 2016 and December 31, 2015 (as adjusted) was as follows. (In millions) March 31, December 31, FHLB Advance, interest at 1.91% per annum, due February 2023 $ 155.0 $ — Convertible Senior Notes, interest at 5% per annum, due May 2017 (1) 194.3 331.5 Convertible Senior Notes, interest at 2% per annum, due April 2020 (2) (3) 491.3 490.8 Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063 (4) 256.9 389.5 Total long-term debt $ 1,097.5 $ 1,211.8 (1) Convertible at any time prior to maturity at the holder’s option, at an initial conversion rate, which is subject to adjustment, of 74.4186 shares per $1,000 principal amount, representing an initial conversion price of approximately $13.44 per share. (2) Prior to January 1, 2020, the 2% Convertible Senior Notes are convertible only upon satisfaction of one or more conditions. One such condition is that during any calendar quarter commencing after March 31, 2014, the last reported sale price of our common stock for each of at least 20 trading days during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter be greater than or equal to 130% of the applicable conversion price on each applicable trading day. The 2% Notes are convertible at an initial conversion rate, which is subject to adjustment, of 143.8332 shares per $1,000 principal amount, representing an initial conversion price of approximately $6.95 per share. 130% of such conversion price is $9.03 . On or after January 1, 2020, holders may convert their notes irrespective of satisfaction of the conditions. (3) Prior to April 10, 2017, the notes will not be redeemable. On any business day on or after April 10, 2017 we may redeem for cash all or part of the notes, at our option, at a redemption rate equal to 100% of the principal amount of the notes being redeemed, plus any accrued and unpaid interest, if the closing sale price of our common stock exceeds 130% of the then prevailing conversion price of the notes for each of at least 20 of the 30 consecutive trading days preceding notice of the redemption. (4) Convertible at any time prior to maturity at the holder’s option, at an initial conversion rate, which is subject to adjustment, of 74.0741 shares per $1,000 principal amount, representing an initial conversion price of approximately $13.50 per share. If a holder elects to convert their debentures, deferred interest owed on the 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. In lieu of issuing shares of common stock upon conversion of the debentures, we may, at our option, make a cash payment to converting holders for all or some of the shares of our common stock otherwise issuable upon conversion. The Convertible Senior Notes and Convertible Junior Subordinated Debentures are obligations of our holding company, MGIC Investment Corporation, and not of its subsidiaries. As of March 31, 2016 , we had approximately $265 million in cash and investments at our holding company. The net unrealized gains on our holding company investment portfolio were approximately $0.1 million as of March 31, 2016 . The modified duration of the holding company investment portfolio, excluding cash and cash equivalents, was 2.4 years at March 31, 2016 . Interest payments on our debt obligations appear below. Three Months Ended (In millions) 2016 2015 FHLB Advance, interest at 1.91% per annum, due February 2023 $ 0.2 $ — Convertible Senior Notes, interest at 5% per annum, due May 2017 1.8 — Convertible Senior Notes, interest at 2% per annum, due April 2020 — — Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063 4.3 — Total interest payments $ 6.3 $ —

Reinsurance

Reinsurance	3 Months Ended
	Mar. 31, 2016
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The effect of all reinsurance agreements on premiums earned and losses incurred is as follows: Three Months Ended March 31, (In thousands) 2016 2015 Premiums earned: Direct $ 255,387 $ 245,748 Assumed 208 338 Ceded (34,254 ) (28,798 ) Net premiums earned $ 221,341 $ 217,288 Losses incurred: Direct $ 92,432 $ 88,036 Assumed 101 568 Ceded (7,521 ) (6,819 ) Net losses incurred $ 85,012 $ 81,785 Quota share reinsurance Effective July 1, 2015, we entered into a quota share reinsurance agreement (“2015 QSR Transaction”) and commuted our prior 2013 quota share reinsurance agreement (“2013 QSR Transaction”). The group of unaffiliated reinsurers are the same under our 2015 QSR Transaction as our prior 2013 QSR Transaction and each has an insurer financial strength rating of A- or better by Standard and Poor’s Rating Services, A.M. Best or both. The 2015 QSR Transaction provides coverage on policies that were in the 2013 QSR Transaction; additional qualifying in force policies as of the agreement effective date which either had no history of defaults, or where a single default had been cured for twelve or more months at the agreement effective date; and all qualifying new insurance written through December 31, 2016. The agreement cedes losses incurred and premiums on or after the effective date through December 31, 2024, at which time the agreement expires. The 2015 QSR Transaction increased the amount of our insurance in force covered by reinsurance and will result in an increase in the amount of premiums and losses ceded. A higher level of losses ceded will reduce our profit commission and in turn will reduce our premium yield. Early termination of the agreement can be elected by us effective December 31, 2018 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 private mortgage insurer eligibility requirements (“PMIERs”) of Fannie Mae and Freddie Mac (collectively, the “GSEs”) for the risk ceded in any required calculation period. The structure of the 2015 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 2015 QSR Transaction, we will receive a profit commission provided that the loss ratio on the loans covered under the agreement remains below 60% . A summary of our quota share reinsurance agreements, excluding captive agreements, for the three months ended March 31, 2016 and 2015 appears as follows. Three Months Ended March 31, (In thousands) 2016 2015 2013 QSR Transaction Ceded premiums written, net of profit commission n/a $ 27,136 Ceded premiums earned, net of profit commission n/a 24,613 Ceded losses incurred n/a 4,873 Ceding commissions (2) n/a 10,122 Profit commission n/a 23,474 2015 QSR Transaction (Effective July 1, 2015) Ceded premiums written, net of profit commission (1) $ 31,666 n/a Ceded premiums earned, net of profit commission (1) 31,666 n/a Ceded losses incurred 8,513 n/a Ceding commissions (2) 11,576 n/a Profit commission 26,215 n/a (1) Effective July 1, 2015 premiums are ceded on an earned and received basis as defined in our 2015 QSR Transaction. (2) Ceding commissions are reported within Other underwriting and operating expenses, net on the consolidated statements of operations. Under the terms of the 2015 QSR Transaction, 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 related to our 2015 QSR Transaction was $18 million as of March 31, 2016 and $11 million as of December 31, 2015 . The reinsurance recoverable balance is secured by funds on deposit from the reinsurers which are based on the funding requirements of PMIERs that address ceded risk. Captive reinsurance In the past, MGIC also obtained captive reinsurance. In a captive reinsurance arrangement, the reinsurer is affiliated with the lender for whom MGIC provides mortgage insurance. As part of our settlement with the Consumer Financial Protection Bureau (“CFPB”) in 2013 and with the Minnesota Department of Commerce (the “MN Department”) in 2015, discussed in Note 5 – “Litigation and Contingencies,” MGIC has agreed to not enter into any new captive reinsurance agreement or reinsure any new loans under any existing captive reinsurance agreement for a period of ten years subsequent to the respective settlements. In accordance with the CFPB settlement, all of our active captive arrangements were placed into run-off. In addition, the GSEs will not approve any future reinsurance or risk sharing transaction with a mortgage enterprise or an affiliate of a mortgage enterprise. Captive agreements were generally written on an annual book of business and each captive reinsurer is required to maintain a separate trust account to support its combined reinsured risk on all annual books. MGIC is the sole beneficiary of the trusts, and the trust accounts are made up of capital deposits by the captive reinsurers, premium deposits by MGIC, and investment income earned. The reinsurance recoverable on loss reserves related to captive agreements was $23 million as of March 31, 2016 which was supported by $123 million of trust assets, while as of December 31, 2015 , the reinsurance recoverable on loss reserves related to captive agreements was $34 million , which was supported by $137 million of trust assets.

Litigation and Contingencies

Litigation and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Litigation and Contingencies	Litigation and Contingencies Before paying a claim, we review the loan and servicing files to determine the appropriateness of the claim amount. All of our insurance policies 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 2015 and the first quarter of 2016, curtailments reduced our average claim paid by approximately 6.7% and 5.1% , respectively. After we pay a claim, servicers and insureds sometimes object to our curtailments and other adjustments. When reviewing the loan file associated with a claim, we may determine that we have the right to rescind coverage on the loan. (In our SEC reports, we refer to insurance rescissions and denials of claims collectively as “rescissions” and variations of that term.) In recent quarters, approximately 5% of claims received in a quarter have been resolved by rescissions, down from the peak of approximately 28% in the first half of 2009. 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. If the insured disputes our right to curtail claims or rescind coverage, 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 would be determined by legal proceedings. Until a liability associated with a settlement agreement or litigation becomes probable and can be reasonably estimated, we consider our claim payment or rescission resolved for financial reporting purposes even though discussions and legal proceedings may have been initiated and are ongoing. Under ASC 450-20, an estimated loss from such discussions and proceedings is accrued for only if we determine that the loss is probable and can be reasonably estimated. The estimated impact that we have recorded is our best estimate of our loss from these matters. If we are not able to implement settlements we consider probable, we intend to defend MGIC vigorously against any related legal proceedings. In addition to the probable settlements for which we have recorded a loss, we are involved in other discussions and/or proceedings with insureds with respect to our claims paying practices. Although it is reasonably possible that when these matters are resolved we will not prevail in all cases, we are unable to make a reasonable estimate or range of estimates of the potential liability. We estimate the maximum exposure associated with matters where a loss is reasonably possible to be approximately $193 million , although we believe we will ultimately resolve these matters for significantly less than this amount. This estimate includes the maximum exposure for losses that we have determined are probable in excess of the provision we have recorded for such losses. The estimates of our maximum exposure referred to above do not include interest or consequential or exemplary damages. Mortgage insurers, including MGIC, have been involved in litigation alleging violations of the anti-referral fee provisions of the Real Estate Settlement Procedures Act, which is commonly known as RESPA, and the notice provisions of the Fair Credit Reporting Act, which is commonly known as FCRA. MGIC’s settlement of class action litigation against it under RESPA became final in 2003. MGIC settled the named plaintiffs’ claims in litigation against it under FCRA in 2004, following denial of class certification. Beginning in 2011, MGIC, together with various mortgage lenders and other mortgage insurers, was named as a defendant in twelve lawsuits, alleged to be class actions, filed in various U.S. District Courts. The complaints in all of the cases alleged various causes of action related to the captive mortgage reinsurance arrangements of the mortgage lenders, including that the lenders’ captive reinsurers received excessive premiums in relation to the risk assumed by those captives, thereby violating RESPA. As of 2015, MGIC had been dismissed from all twelve cases. There can be no assurance that we will not be subject to further litigation under RESPA (or FCRA) or that the outcome of any such litigation would not have a material adverse effect on us. In 2013, we entered into a settlement with the CFPB that resolved a federal investigation of MGIC’s participation in captive reinsurance arrangements without the CFPB or a court making any findings of wrongdoing. As part of the settlement, MGIC agreed that it would not enter into any new captive reinsurance agreement or reinsure any new loans under any existing captive reinsurance agreement for a period of ten years . MGIC had voluntarily suspended most of its captive arrangements in 2008 in response to market conditions and GSE requests. In connection with the settlement, MGIC paid a civil penalty of $2.65 million and the court issued an injunction prohibiting MGIC from violating any provisions of RESPA. In 2015, MGIC executed a Consent Order with the MN Department that resolved that department’s investigation of captive reinsurance matters without making any findings of wrongdoing. The Consent Order provided, among other things, that MGIC is prohibited from entering into any new captive reinsurance agreement or reinsuring any new loans under any existing captive reinsurance agreement for a period of ten years . Various regulators, including the CFPB, state insurance commissioners and state attorneys general may bring other actions seeking various forms of relief in connection with alleged violations of RESPA. The insurance law provisions of many states prohibit paying for the referral of insurance business and provide various mechanisms to enforce this prohibition. While we believe our practices are in conformity with applicable laws and regulations, it is not possible to predict the eventual scope, duration or outcome of any such reviews or investigations nor is it possible to predict their effect on us or the mortgage insurance industry. Through a non-insurance subsidiary, we utilize our underwriting skills to provide an outsourced underwriting service to our customers known as contract underwriting. As part of the contract underwriting activities, that subsidiary is responsible for the quality of the underwriting decisions in accordance with the terms of the contract underwriting agreements with customers. That subsidiary may be required to provide certain remedies to its customers if certain standards relating to the quality of our underwriting work are not met, and we have an established reserve for such future obligations. Claims for remedies may be made a number of years after the underwriting work was performed. Beginning in the second half of 2009, our subsidiary experienced an increase in claims for contract underwriting remedies, which continued throughout 2012. The underwriting remedy expense for 2015 was approximately $1 million , but may increase in the future. 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 results of operations. See Note 11 – “Income Taxes” for a description of federal income tax contingencies.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share Basic earnings per share (“EPS”) is calculated by dividing net income by the weighted average number of common shares outstanding during the reporting period. Diluted EPS includes the components of basic EPS and also gives effect to dilutive common equivalent shares outstanding during the reporting period. We calculate diluted EPS using the treasury stock method for unvested restricted stock, and the if-converted method for convertible debt instruments. For unvested restricted stock, assumed proceeds under the treasury stock method would include unamortized compensation expense and windfall tax benefits or shortfalls. The determination of potentially issuable shares from our convertible debt instruments does not consider 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, interest expense, net of tax, related to dilutive convertible debt instruments is added back to earnings in calculating diluted EPS. The following table reconciles the numerators and denominators used to calculate basic and diluted EPS and also indicates the number of antidilutive securities. Three months ended March 31, (In thousands, except per share data) 2016 2015 Basic earnings per share: Net income $ 69,191 $ 133,076 Weighted average common shares outstanding 340,144 339,107 Basic income per share $ 0.20 $ 0.39 Diluted earnings per share: Net income $ 69,191 $ 133,076 Interest expense, net of tax (1) : 2% Convertible Senior Notes due 2020 1,982 3,049 5% Convertible Senior Notes due 2017 2,678 4,692 9% Convertible Junior Subordinated Debentures due 2063 — 8,765 Diluted income available to common shareholders $ 73,851 $ 149,582 Weighted average shares - basic 340,144 339,107 Effect of dilutive securities: Unvested restricted stock units 1,679 2,569 2% Convertible Senior Notes due 2020 71,917 71,917 5% Convertible Senior Notes due 2017 17,625 25,674 9% Convertible Junior Subordinated Debentures due 2063 — 28,854 Weighted average shares - diluted 431,365 468,121 Diluted income per share $ 0.17 $ 0.32 Antidilutive securities (in millions) 23.3 — (1) Due to the valuation allowance recorded against deferred tax assets, the three months ended March 31, 2015 were not tax effected. The three months ended March 31, 2016 have been tax effected at a rate of 35%.

Investments

Investments	3 Months Ended
	Mar. 31, 2016
Investments [Abstract]
Investments	Investments The amortized cost, gross unrealized gains and losses and fair value of the investment portfolio at March 31, 2016 and December 31, 2015 are shown below. March 31, 2016 (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 $ 147,189 $ 2,474 $ (1,135 ) $ 148,528 Obligations of U.S. states and political subdivisions 1,854,959 60,677 (2,506 ) 1,913,130 Corporate debt securities 1,856,376 16,315 (18,484 ) 1,854,207 Asset-backed securities 110,241 176 (89 ) 110,328 Residential mortgage-backed securities 255,344 452 (5,155 ) 250,641 Commercial mortgage-backed securities 220,719 1,678 (1,701 ) 220,696 Collateralized loan obligations 61,350 25 (991 ) 60,384 Total debt securities 4,506,178 81,797 (30,061 ) 4,557,914 Equity securities 6,209 87 (7 ) 6,289 Total investment portfolio $ 4,512,387 $ 81,884 $ (30,068 ) $ 4,564,203 December 31, 2015 (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 $ 160,393 $ 2,133 $ (1,942 ) $ 160,584 Obligations of U.S. states and political subdivisions 1,766,407 33,410 (7,290 ) 1,792,527 Corporate debt securities 2,046,697 2,836 (44,770 ) 2,004,763 Asset-backed securities 116,764 56 (203 ) 116,617 Residential mortgage-backed securities 265,879 161 (8,392 ) 257,648 Commercial mortgage-backed securities 237,304 162 (3,975 ) 233,491 Collateralized loan obligations 61,345 3 (1,148 ) 60,200 Debt securities issued by foreign sovereign governments 29,359 2,474 (102 ) 31,731 Total debt securities 4,684,148 41,235 (67,822 ) 4,657,561 Equity securities 5,625 38 (18 ) 5,645 Total investment portfolio $ 4,689,773 $ 41,273 $ (67,840 ) $ 4,663,206 (1) At March 31, 2016 and December 31, 2015 , there were no other-than-temporary impairment losses recorded in other comprehensive income. During the first quarter of 2016, we substantially liquidated our Australian entities and repatriated most assets, including proceeds from the monetization of our Australian investment portfolio. As of March 31, 2016 we held no investments in foreign sovereign governments. As discussed in Note 3 - “Debt” we are required to maintain collateral of at least 102% of the outstanding principal balance of the Advance. As of March 31, 2016 we pledged eligible collateral with a total fair value of $164.6 million . The amortized cost and fair values of debt securities at March 31, 2016 , by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Because most asset-backed and mortgage-backed securities and collateralized loan obligations provide for periodic payments throughout their lives, they are listed below in separate categories. March 31, 2016 (In thousands) Amortized Cost Fair Value Due in one year or less $ 310,484 $ 311,202 Due after one year through five years 1,265,465 1,278,045 Due after five years through ten years 1,120,853 1,122,243 Due after ten years 1,161,722 1,204,375 $ 3,858,524 $ 3,915,865 Asset-backed securities 110,241 110,328 Residential mortgage-backed securities 255,344 250,641 Commercial mortgage-backed securities 220,719 220,696 Collateralized loan obligations 61,350 60,384 Total as of March 31, 2016 $ 4,506,178 $ 4,557,914 At March 31, 2016 and December 31, 2015 , the investment portfolio had gross unrealized losses of $30.1 million and $67.8 million , respectively. For those securities in an unrealized loss position, the length of time the securities were in such a position, as measured by their month-end fair values, is as follows: March 31, 2016 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 $ 26,586 $ (1,094 ) $ 2,998 $ (41 ) $ 29,584 $ (1,135 ) Obligations of U.S. states and political subdivisions 105,443 (763 ) 60,616 (1,743 ) 166,059 (2,506 ) Corporate debt securities 350,566 (7,932 ) 348,277 (10,552 ) 698,843 (18,484 ) Asset-backed securities 29,107 (42 ) 11,019 (47 ) 40,126 (89 ) Residential mortgage-backed securities 14,548 (103 ) 204,585 (5,052 ) 219,133 (5,155 ) Commercial mortgage-backed securities 60,778 (925 ) 56,126 (776 ) 116,904 (1,701 ) Collateralized loan obligations — — 51,907 (991 ) 51,907 (991 ) Equity securities 91 — 209 (7 ) 300 (7 ) Total $ 587,119 $ (10,859 ) $ 735,737 $ (19,209 ) $ 1,322,856 $ (30,068 ) December 31, 2015 Less Than 12 Months 12 Months or Greater Total (In thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (In thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 60,548 $ (1,467 ) $ 1,923 $ (475 ) $ 62,471 $ (1,942 ) Obligations of U.S. states and political subdivisions 417,615 (6,404 ) 37,014 (886 ) 454,629 (7,290 ) Corporate debt securities 1,470,628 (38,519 ) 114,982 (6,251 ) 1,585,610 (44,770 ) Asset-backed securities 86,604 (173 ) 5,546 (30 ) 92,150 (203 ) Residential mortgage-backed securities 35,064 (312 ) 209,882 (8,080 ) 244,946 (8,392 ) Commercial mortgage-backed securities 134,488 (2,361 ) 69,927 (1,614 ) 204,415 (3,975 ) Collateralized loan obligations — — 51,750 (1,148 ) 51,750 (1,148 ) Debt securities issued by foreign sovereign governments 4,463 (102 ) — — 4,463 (102 ) Equity securities 355 (8 ) 171 (10 ) 526 (18 ) Total $ 2,209,765 $ (49,346 ) $ 491,195 $ (18,494 ) $ 2,700,960 $ (67,840 ) The unrealized losses in all categories of our investments at March 31, 2016 and December 31, 2015 were primarily caused by the difference in interest rates at each respective period, compared to interest rates at the time of purchase. There were 316 and 303 securities in an unrealized loss position at March 31, 2016 and December 31, 2015 , respectively. During each of the three months ended March 31, 2016 and 2015 there were no other-than-temporary impairments (“OTTI”) recognized. The net realized investment gains on the investment portfolio are as follows: Three Months Ended (In thousands) 2016 2015 Realized investment gains (losses) on investments: Fixed maturities $ 3,054 $ 26,324 Equity securities 2 3 Net realized investment gains $ 3,056 $ 26,327 Three Months Ended (In thousands) 2016 2015 Realized investment gains (losses) on investments: Gains on sales $ 4,104 $ 27,206 Losses on sales (1,048 ) (879 ) Net realized investment gains $ 3,056 $ 26,327

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Our estimates of fair value for financial assets and financial liabilities are based on the framework established in the fair value accounting guidance. The framework is based on the inputs used in valuation, gives the highest priority to quoted prices in active markets and requires that observable inputs be used in the valuations when available. To determine the fair value of securities available-for-sale in Level 1 and Level 2 of the fair value hierarchy, independent pricing sources 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. A variety of inputs are utilized 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 data published in 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. 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. In addition, on a quarterly basis, we perform quality controls over values received from the pricing sources which also include reviewing tolerance reports, trading information, data changes, and directional moves compared to market moves. We have not made any adjustments to the prices obtained from the independent pricing sources. In accordance with fair value guidance, we applied the following fair value hierarchy in order to measure fair value for assets and liabilities: Level 1 - Quoted prices for identical instruments in active markets that we can access. Financial assets utilizing Level 1 inputs primarily include U.S. Treasury securities, equity securities, and Australian government and semi government securities. 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 financial instrument. The observable inputs are used in valuation models to calculate the fair value of the financial instruments. Financial assets utilizing Level 2 inputs primarily include obligations of U.S. government corporations and agencies, corporate bonds, mortgage-backed securities, and most municipal bonds. The independent pricing sources utilize these approaches to determine the fair value of the securities in Level 2 of the fair value hierarchy based on type of investment: Corporate Debt & U.S. Government and Agency Bonds are evaluated by surveying the dealer community, obtaining relevant trade data, benchmark quotes and spreads and incorporating this information into the evaluation process. Obligations of U.S. States & Political Subdivisions are evaluated 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 are evaluated 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 are evaluated using valuation 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 utilizes 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 are evaluated 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 market color as available are used, resulting in tranche-specific spreads. Level 3 - Valuations derived from valuation techniques in which one or more significant inputs or value drivers are unobservable or from par values for equity securities restricted in their ability to be redeemed or sold. 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 utilizing Level 3 inputs primarily include equity securities that can only be redeemed or sold at their par value and only to the security issuer and certain state premium tax credit investments. The state premium tax credit investments have an average maturity of less than 2 years , credit ratings of AA+ or higher, and their balance reflects their remaining scheduled payments discounted at an average annual rate of 7.2% . 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. Fair value measurements for assets measured at fair value included the following as of March 31, 2016 and December 31, 2015 : March 31, 2016 (In thousands) Total 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 $ 148,528 $ 51,448 $ 97,080 $ — Obligations of U.S. states and political subdivisions 1,913,130 — 1,911,938 1,192 Corporate debt securities 1,854,207 — 1,854,207 — Asset-backed securities 110,328 — 110,328 — Residential mortgage-backed securities 250,641 — 250,641 — Commercial mortgage-backed securities 220,696 — 220,696 — Collateralized loan obligations 60,384 — 60,384 — Total debt securities 4,557,914 51,448 4,505,274 1,192 Equity securities (1) 6,289 2,868 — 3,421 Total investment portfolio $ 4,564,203 $ 54,316 $ 4,505,274 $ 4,613 Real estate acquired (2) $ 12,849 $ — $ — $ 12,849 December 31, 2015 (In thousands) Total 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 $ 160,584 $ 46,197 $ 114,387 $ — Obligations of U.S. states and political subdivisions 1,792,527 — 1,791,299 1,228 Corporate debt securities 2,004,763 — 2,004,763 — Asset-backed securities 116,617 — 116,617 — Residential mortgage-backed securities 257,648 — 257,648 — Commercial mortgage-backed securities 233,491 — 233,491 — Collateralized loan obligations 60,200 — 60,200 — Debt securities issued by foreign sovereign governments 31,731 31,731 — — Total debt securities 4,657,561 77,928 4,578,405 1,228 Equity securities (1) 5,645 2,790 — 2,855 Total investment portfolio $ 4,663,206 $ 80,718 $ 4,578,405 $ 4,083 Real estate acquired (2) $ 12,149 $ — $ — $ 12,149 (1) Equity securities in Level 3 are carried at cost, which approximates fair value. (2) Real estate acquired through claim settlement, which is held for sale, is reported in Other assets on the consolidated balance sheets. There were no transfers of securities between Level 1 and Level 2 during the first three months of 2016. For assets measured at fair value using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances for the three months ended March 31, 2016 and 2015 is shown in the following tables. There were no transfers into or out of Level 3 in those periods and there were no losses included in earnings for those periods attributable to the change in unrealized losses on assets still held at the end of the applicable period. (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2015 $ 1,228 $ 2,855 $ 4,083 $ 12,149 Total realized/unrealized gains (losses): Included in earnings and reported as losses incurred, net — — — (293 ) Purchases — 3,091 3,091 12,267 Sales (36 ) (2,525 ) (2,561 ) (11,274 ) Balance at March 31, 2016 $ 1,192 $ 3,421 $ 4,613 $ 12,849 (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2014 $ 1,846 $ 321 $ 2,167 $ 12,658 Total realized/unrealized gains (losses): Included in earnings and reported as losses incurred, net — — — (503 ) Purchases 7 — 7 10,797 Sales (62 ) — (62 ) (12,055 ) Balance at March 31, 2015 $ 1,791 $ 321 $ 2,112 $ 10,897 Authoritative guidance over disclosures about the fair value of financial instruments requires additional disclosure for financial instruments not measured at fair value. Certain financial instruments, including insurance contracts, are excluded from these fair value disclosure requirements. The carrying values of cash and cash equivalents (Level 1) and accrued investment income (Level 2) approximated their fair values. Additional fair value disclosures related to our investment portfolio are included in Note 7 – “Investments.” Financial Liabilities Not Measured at Fair Value We incur financial liabilities in the normal course of our business. The following tables present the carrying value and fair value of our financial liabilities disclosed, but not carried, at fair value at March 31, 2016 and December 31, 2015 . The fair values of our Convertible Senior Notes and Convertible Junior Subordinated Debentures were based on observable market prices and the fair value of the Federal Home Loan Bank Advance was estimated using discounted cash flows on current incremental borrowing rates for similar borrowing arrangements, and in all cases they are categorized as Level 2. March 31, 2016 (In thousands) Carrying Value Fair Value Financial liabilities: FHLB Advance due 2023 $ 155,000 $ 156,831 Convertible Senior Notes due 2017 194,319 203,771 Convertible Senior Notes due 2020 491,305 630,310 Convertible Junior Subordinated Debentures due 2063 256,872 292,754 Total Debt $ 1,097,496 $ 1,283,666 December 31, 2015 (In thousands) Carrying Value Fair Value Financial liabilities: Convertible Senior Notes due 2017 $ 331,546 $ 345,616 Convertible Senior Notes due 2020 490,755 701,955 Convertible Junior Subordinated Debentures due 2063 389,522 455,067 Total Debt $ 1,211,823 $ 1,502,638

Other Comprehensive Income

Other Comprehensive Income	3 Months Ended
	Mar. 31, 2016
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other Comprehensive Income	Other Comprehensive Income The pretax components of our other comprehensive income (loss) and the related income tax (expense) benefit for the three months ended March 31, 2016 and 2015 are included in the following table. Three Months Ended March 31, (In thousands) 2016 2015 Net unrealized holding gains arising during the period $ 78,383 $ 19,721 Income tax expense (27,556 ) (6,876 ) Valuation allowance (1) — 6,718 Net of taxes 50,827 19,563 Net changes in benefit plan assets and obligations (474 ) (700 ) Income tax benefit 166 245 Valuation allowance (1) — (245 ) Net of taxes (308 ) (700 ) Net changes in unrealized foreign currency translation adjustment (1,496 ) (3,102 ) Income tax benefit 521 1,088 Net of taxes (975 ) (2,014 ) Total other comprehensive income 76,413 15,919 Total income tax (expense) benefit, net of valuation allowance (26,869 ) 930 Total other comprehensive income, net of tax $ 49,544 $ 16,849 (1) See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets. The pretax and related income tax (expense) benefit components of the amounts reclassified from our accumulated other comprehensive loss to our consolidated statements of operations for the three months ended March 31, 2016 and 2015 are included in the following table. Three Months Ended March 31, (In thousands) 2016 2015 Reclassification adjustment for net realized gains (losses) included in net income (1) $ 612 $ 11,234 Income tax expense (92 ) (3,931 ) Valuation allowance (2) — 3,926 Net of taxes 520 11,229 Reclassification adjustment related to benefit plan assets and obligations (3) 474 700 Income tax expense (166 ) (245 ) Valuation allowance (2) — 245 Net of taxes 308 700 Total reclassifications 1,086 11,934 Total income tax expense, net of valuation allowance (258 ) (5 ) Total reclassifications, net of tax $ 828 $ 11,929 (1) Increases (decreases) Net realized investment gains on the consolidated statements of operations. (2) See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets. (3) Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations. Changes in our accumulated other comprehensive loss, including amounts reclassified from other comprehensive income (loss), for the three months ended March 31, 2016 are included in the table below. Three Months Ended March 31, 2016 (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 accumulated other comprehensive loss Balance at December 31, 2015, net of tax $ (17,148 ) $ (44,652 ) $ 920 $ (60,880 ) Other comprehensive income (loss) before reclassifications 51,347 — (975 ) 50,372 Less: Amounts reclassified from accumulated other comprehensive income (loss) 520 308 — 828 Balance at March 31, 2016, net of tax $ 33,679 $ (44,960 ) $ (55 ) $ (11,336 )

Benefit Plans

Benefit Plans	3 Months Ended
	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	Benefit Plans The following table provides the components of net periodic benefit cost for the pension, supplemental executive retirement and other postretirement benefit plans: Three Months Ended March 31, (In thousands) Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits 2016 2015 2016 2015 Service cost $ 2,163 $ 2,448 $ 175 $ 202 Interest cost 3,929 3,908 172 178 Expected return on plan assets (4,889 ) (5,295 ) (1,222 ) (1,248 ) Recognized net actuarial loss (gain) 1,361 1,209 — (35 ) Amortization of prior service cost (172 ) (211 ) (1,662 ) (1,662 ) Net periodic benefit cost (benefit) $ 2,392 $ 2,059 $ (2,537 ) $ (2,565 ) We currently intend to make a contribution of $11.4 million to our qualified pension plan and supplemental executive retirement plan in 2016.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Valuation Allowance We review the need to maintain a deferred tax asset valuation allowance on a quarterly basis. We analyze many factors, among which are the severity and frequency of operating losses, our capacity for the carryback or carryforward of any losses, the existence and current level of taxable operating income, operating results on a three year cumulative basis, the expected occurrence of future income or loss, the expiration dates of the loss carryforwards, the cyclical nature of our operating results, and available tax planning strategies. Based on our analysis, we reduced our benefit from income tax through the recognition of a valuation allowance from the first quarter of 2009 through the second quarter of 2015. In the third quarter of 2015, based on our analysis, we concluded that it was more likely than not that our deferred tax assets would be fully realizable and that the valuation allowance was no longer necessary. Therefore, we reversed the valuation allowance. The effect of the change in valuation allowance on the provision for income taxes was as follows: Three months ended March 31, (In thousands) 2016 2015 Provision for income tax $ 34,497 $ 47,883 Change in valuation allowance — (44,498 ) Provision for income taxes $ 34,497 $ 3,385 The change in the valuation allowance that was included in other comprehensive income for the three months ended March 31, 2015 was a decrease of $6.5 million . We have approximately $1.9 billion of net operating loss (“NOL”) carryforwards on a regular tax basis and $1.0 billion of NOL carryforwards for computing the alternative minimum tax as of March 31, 2016 . Any unutilized carryforwards are scheduled to expire at the end of tax years 2029 through 2033. Tax Contingencies 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”). The IRS indicated that it did not believe that, for various reasons, we had established sufficient tax basis in the REMIC residual interests to deduct the losses from taxable income. We appealed these assessments within the IRS and in August 2010, we reached a tentative settlement agreement with the IRS which was not finalized. In 2014, we received Notices of Deficiency (commonly referred to as “90 day letters”) covering the 2000-2007 tax years. The Notices of Deficiency reflect taxes and penalties related to the REMIC matters of $197.5 million and at March 31, 2016 , there would also be interest related to these matters of approximately $187.4 million . In 2007, we made a payment of $65.2 million to the United States Department of the Treasury which will reduce any amounts we would ultimately owe. The Notices of Deficiency also reflect additional amounts due of $261.4 million , which are primarily associated with the disallowance of the carryback of the 2009 net operating loss to the 2004-2007 tax years. We believe the IRS included the carryback adjustments as a precaution to keep open the statute of limitations on collection of the tax that was refunded when this loss was carried back, and not because the IRS actually intends to disallow the carryback permanently. We filed a petition with the U.S. Tax Court contesting most of the IRS’ proposed adjustments reflected in the Notices of Deficiency and the IRS has filed an answer to our petition which continues to assert their claim. The case has twice been scheduled for trial and in each instance, the parties jointly filed, and the U.S. Tax Court approved (most recently in February 2016), motions for continuance to postpone the trial date. Also in February 2016, the U.S. Tax Court approved a joint motion to consolidate for trial, briefing, and opinion, our case with similar cases of Radian Group, Inc., as successor to Enhance Financial Services Group, Inc., et al. Litigation to resolve our dispute with the IRS could be lengthy and costly in terms of legal fees and related expenses. We can provide no assurance regarding the outcome of any such litigation or whether a compromised settlement with the IRS will ultimately be reached and finalized. Depending on the outcome of this matter, additional state income taxes and state interest may become due when a final resolution is reached. As of March 31, 2016 , those state taxes and interest would approximate $49.3 million . In addition, there could also be state tax penalties. Our total amount of unrecognized tax benefits as of March 31, 2016 is $107.4 million , which represents the tax benefits generated by the REMIC portfolio included in our tax returns that we have not taken benefit for in our financial statements, including any related interest. We continue to believe that our previously recorded tax provisions and liabilities are appropriate. However, we would need to make appropriate adjustments, which could be material, to our tax provision and liabilities if our view of the probability of success in this matter changes, and the ultimate resolution of this matter could have a material negative impact on our effective tax rate, results of operations, cash flows, available assets and statutory capital. In this regard, see Note 15 – “Capital Requirements.” The total amount of the unrecognized tax benefits, related to our aforementioned REMIC issue that would affect our effective tax rate is $94.1 million . We recognize interest accrued and penalties related to unrecognized tax benefits in income taxes. As of March 31, 2016 and December 31, 2015 , we had accrued $28.1 million and $27.8 million , respectively, for the payment of interest.

Loss Reserves

Loss Reserves	3 Months Ended
	Mar. 31, 2016
Insurance Loss Reserves [Abstract]
Loss Reserves	Loss Reserves We establish reserves to recognize the estimated liability for losses and loss adjustment expenses (“LAE”) related to defaults on insured mortgage loans. Loss reserves are established by estimating the number of defaulted loans that will result in a claim payment, which is referred to as the claim rate, and further estimating the amount of the claim payment, which is referred to as claim severity. Estimation of losses is inherently judgmental. The conditions that affect the claim rate and claim severity include the current and future state of the domestic economy, including unemployment, and the current and future strength of local housing markets; exposure on insured loans; the amount of time between default and claim filing; and curtailments. 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 borrower 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 results of operations and capital position, even in a stable economic environment. The following table provides a reconciliation of beginning and ending loss reserves for the three months ended March 31, 2016 and 2015 : Three months ended March 31, (In thousands) 2016 2015 Reserve at beginning of period $ 1,893,402 $ 2,396,807 Less reinsurance recoverable 44,487 57,841 Net reserve at beginning of period 1,848,915 2,338,966 Losses incurred: Losses and LAE incurred in respect of defaults related to: Current year 92,479 109,381 Prior years (1) (7,467 ) (27,596 ) Subtotal 85,012 81,785 Losses paid: Losses and LAE paid in respect of defaults related to: Current year 204 312 Prior years 221,457 231,230 Reinsurance terminations (2) (4 ) — Subtotal 221,657 231,542 Net reserve at end of period 1,712,270 2,189,209 Plus reinsurance recoverables 41,119 55,415 Reserve at end of period $ 1,753,389 $ 2,244,624 (1) A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves. (2) In a termination or commutation, the reinsurance agreement is cancelled, with no future premium ceded and funds for any incurred but unpaid losses transferred to us. The transferred funds result in an increase in our investment portfolio (including cash and cash equivalents) and a decrease in net losses paid (reduction in losses incurred). In addition, there is an offsetting decrease in the reinsurance recoverable (increase in losses incurred), and thus there is no net impact to losses incurred. The “Losses incurred” section of the table above shows losses incurred on defaults that occurred in the current year and in prior years. The amount of losses incurred relating to defaults that occurred in the current year represents the estimated amount to be ultimately paid on such defaults. The amount of losses incurred relating to defaults received in prior years represents the actual claim rate and severity associated with those defaults resolved in the current year differing from the estimated liability at the prior year-end, as well as a re-estimation of amounts to be ultimately paid on defaults continuing from the end of the prior year. This re-estimation of the estimated claim rate and estimated severity is the result of our review of current trends in the default inventory, such as percentages of defaults that have resulted in a claim, the amount of the claims relative to the average loan exposure, changes in the relative level of defaults by geography and changes in average loan exposure. Losses incurred on defaults received in the current year decreased in the first three months of 2016 compared to the same period in 2015 , primarily due to a decrease in the number of new defaults, net of related cures. The prior year development of the reserves in the first three months of 2016 and 2015 is reflected in the following table. Three months ended March 31, (In millions) 2016 2015 Decrease in estimated claim rate on primary defaults $ (26 ) $ (39 ) Increase in estimated severity on primary defaults 22 17 Change in estimates related to pool reserves, LAE reserves and reinsurance (3 ) (6 ) Total prior year loss development (1) $ (7 ) $ (28 ) (1) A negative number for prior year loss development indicates a redundancy of prior year loss reserves, and a positive number indicates a deficiency of prior year loss reserves. For the three months ended March 31, 2016 and 2015 we experienced favorable prior year loss reserve development. This development was, in part, due to the resolution of approximately 28% and 24% of the prior year default inventory during the three months ended March 31, 2016 and 2015 , respectively. During the first three months of 2016, we experienced improved cure rates on prior year defaults, which was offset in part by an increase in severity on the prior year defaults. In addition to the resolution of defaults, the first three months of 2015 were also favorably impacted by $20 million due to re-estimation of previously recorded reserves relating to disputes on our claims paying practices and adjustments to incurred but not reported losses (IBNR). The favorable development in the first quarter of 2015 was offset, in part, by an increase in the severity on prior year defaults remaining in the delinquent inventory. The “Losses paid” section of the table above shows the breakdown between claims paid on new default notices in the current year and claims paid on defaults from prior years. Until a few years ago, it took, on average, approximately twelve months for a default that is not cured to develop into a paid claim. Over the past several years, the average time it takes to receive a claim associated with a default has increased. This is, 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. It is difficult to estimate how long it may take for current and future defaults that do not cure to develop into paid claims. During the first quarter of 2016, our losses paid included $47 million associated with settlements for claims paying practices and a nonperforming loan sale. These settlements reduced our delinquent inventory by 1,138 notices. These settlements had no material impact on our losses incurred, net. The liability associated with our estimate of premiums to be refunded on expected claim payments is accrued for separately at March 31, 2016 and December 31, 2015 and approximated $99 million and $102 million , respectively. This liability was included in “Other liabilities” on our consolidated balance sheets. A rollforward of our primary default inventory for the three months ended March 31, 2016 and 2015 appears in the following table. 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. Three months ended March 31, 2016 2015 Default inventory at beginning of period 62,633 79,901 New notices 16,731 18,896 Cures (19,053 ) (21,767 ) Paids (including those charged to a deductible or captive) (3,373 ) (4,573 ) Rescissions and denials (210 ) (221 ) Items removed from inventory resulting from settlements (1) (1,138 ) — Default inventory at end of period 55,590 72,236 (1) Includes 732 loans whose insurance was terminated by agreement to settle coverage on certain non-performing loans, and 406 loans for which we had previously suspended rescissions and that were included in a rescission settlement agreement. Both agreements became effective in the first quarter of 2016 and neither had a material financial impact in the quarter. The decrease in the primary default inventory experienced during 2016 and 2015 was generally across all markets and primarily in book years 2008 and prior. As of March 31, 2016 the percentage of loans in the inventory that have been in default for 12 or more consecutive months remained consistent compared with the prior year end and declined compared to one year prior, as shown in the following table. Historically as a default ages it becomes more likely to result in a claim. The percentage of loans that have been in default for 12 or more consecutive months and the number of loans in our primary claims received inventory have been affected by our suspended rescissions and the resolution of certain of those rescissions discussed below and in Note 5 – “Litigation and Contingencies.” March 31, 2016 December 31, 2015 March 31, 2015 Consecutive months in default 3 months or less 10,120 18 % 13,053 21 % 11,604 16 % 4 - 11 months 15,319 28 % 15,763 25 % 18,940 26 % 12 months or more (1) 30,151 54 % 33,817 54 % 41,692 58 % Total primary default inventory 55,590 100 % 62,633 100 % 72,236 100 % Primary claims received inventory included in ending default inventory 2,267 4 % 2,769 4 % 4,448 6 % (1) Approximately 49% , 50% , and 53% of the primary default inventory in default for 12 consecutive months or more has been in default for at least 36 consecutive months as of March 31, 2016 , December 31, 2015 , and March 31, 2015 , respectively. The number of months a loan is in the default inventory can differ from the number of payments that the borrower has not made or is considered delinquent. These differences typically result from a borrower making monthly payments that do not result in the loan becoming fully current. The number of payments that a borrower is delinquent is shown in the table below. March 31, 2016 December 31, 2015 March 31, 2015 Number of payments delinquent 3 payments or less 16,864 30 % 20,360 33 % 19,159 27 % 4 - 11 payments 14,595 26 % 15,092 24 % 18,372 25 % 12 payments or more 24,131 44 % 27,181 43 % 34,705 48 % Total primary default inventory 55,590 100 % 62,633 100 % 72,236 100 % Pool insurance default inventory decreased to 2,247 at March 31, 2016 from 2,739 at December 31, 2015 . The pool insurance default inventory was 3,350 at March 31, 2015 . 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. The liability associated with our estimate of premiums to be refunded on expected future rescissions is accrued for separately. At March 31, 2016 and December 31, 2015 the estimate of this liability totaled $5 million and $7 million , respectively. This liability was included in “Other liabilities” on our consolidated balance sheets. For information about discussions and legal proceedings with customers with respect to our claims paying practices, including settlements that we believe are probable, as defined in ASC 450-20, see Note 5 – “Litigation and Contingencies.”

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2016
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Capital transactions As described in Note 3 - “Debt” the purchase of a portion of our 9% Debentures by MGIC, and corresponding elimination of the purchased 9% Debentures in consolidation, resulted in a reduction to our consolidated shareholders’ equity of approximately $9.8 million as of March 31, 2016 . This reduction represents the allocated portion of the consideration paid to reacquire the equity component of the 9% Debentures. The reduction was recognized in paid-in capital and was less than the amount ascribed to paid-in capital at original issuance of the 9% Debentures. Shareholders Rights Agreement Our Amended and Restated Shareholders Rights Agreement dated July 23, 2015, which was approved by shareholders, (the “Agreement”) seeks to diminish the risk that our ability to use our NOLs to reduce potential future federal income tax obligations may become substantially limited and to deter certain abusive takeover practices. The benefit of the NOLs would be substantially limited, and the timing of the usage of the NOLs could be substantially delayed, if we were to experience an “ownership change” as defined by Section 382 of the Internal Revenue Code. Under the Agreement each outstanding share of our Common Stock is accompanied by one Right. The “Distribution Date” occurs on the earlier of ten days after a public announcement that a person has become an “Acquiring Person”, or ten business days after a person announces or begins a tender offer in which consummation of such offer would result in a person becoming an “Acquiring Person”. An “Acquiring Person” is any person that becomes, by itself or together with its affiliates and associates, a beneficial owner of 5% or more of the shares of our Common Stock then outstanding, but excludes, among others, certain exempt and grandfathered persons as defined in the Agreement. The Rights are not exercisable until the Distribution Date. Each Right will initially entitle shareholders to buy one-tenth of one share of our Common Stock at a Purchase Price of $45 per full share (equivalent to $4.50 for each one-tenth share), subject to adjustment. Each exercisable Right (subject to certain limitations) will entitle its holder to purchase, at the Rights’ then-current Purchase Price, a number of our shares of Common Stock (or if after the Shares Acquisition Date, we are acquired in a business combination, common shares of the acquiror) having a market value at the time equal to twice the Purchase Price. The Rights will expire on August 1, 2018, or earlier as described in the Agreement. The Rights are redeemable at a price of $0.001 per Right at any time prior to the time a person becomes an Acquiring Person. Other than certain amendments, the Board of Directors may amend the Rights in any respect without the consent of the holders of the Rights.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation We have incentive stock plans under which restricted stock units (“RSUs”) were granted to employees. Our annual grant of share-based compensation to employees takes place during the first quarter of each fiscal year. 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 incentive plans generally vest over periods ranging from one to three years . The number of shares granted to employees and the weighted average fair value per share during the periods presented were (shares in thousands): Three months ended March 31, 2016 2015 Shares Granted Weighted Average Share Fair Value Shares Granted Weighted Average Share Fair Value RSUs subject to performance conditions 1,257 $ 5.66 1,110 $ 8.98 RSUs subject only to service conditions 433 5.67 408 8.98

Capital Requirements

Capital Requirements	3 Months Ended
	Mar. 31, 2016
Statutory Capital [Abstract]
Capital Requirements	Capital Requirements Capital - GSEs Substantially all of our insurance written since 2008 has been for loans purchased by the GSEs. The PMIERs of the GSEs include financial requirements that 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 and are calculated from tables of factors with several risk dimensions and are subject to a floor amount). Based on our interpretation of the PMIERs, as of March 31, 2016 , MGIC’s Available Assets are in excess of its Minimum Required Assets; and MGIC is in compliance with the financial requirements of the PMIERs and eligible to insure loans purchased by the GSEs. 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 risk in force (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 March 31, 2016 , MGIC’s risk-to-capital ratio was 12.3 to 1 , below the maximum allowed by the jurisdictions with State Capital Requirements, and its policyholder position was $1.1 billion above the required MPP of $1.1 billion . In calculating our risk-to-capital ratio and MPP, we are allowed full credit for the risk ceded under our reinsurance transaction 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 agreement, without penalty. At this time, we expect MGIC to continue to comply with the current State Capital Requirements; however, you should read the rest of these financial statement footnotes for information about matters that could negatively affect such compliance. At March 31, 2016 , the risk-to-capital ratio of our combined insurance operations (which includes reinsurance affiliates) was 13.8 to 1 . Reinsurance agreements with affiliates permit MGIC to write insurance with a higher coverage percentage than it could on its own under certain state-specific requirements. A higher risk-to-capital ratio on a combined basis may indicate that, in order for MGIC to continue to utilize reinsurance agreements with its affiliates, additional capital contributions to the reinsurance affiliates could be needed. During the first quarter of 2016 MGIC received approval from the OCI to pay a $16 million dividend to our holding company, which was paid in April, its first dividend since 2008. Any additional dividends paid by MGIC to our holding company in 2016 would require OCI approval under the adjusted statutory net income regulations discussed below. MGIC is subject to statutory regulations as to payment of dividends. The maximum amount of dividends that MGIC may pay in any twelve-month period without regulatory approval by the OCI is the lesser of adjusted statutory net income or 10% of statutory policyholders’ surplus as of the preceding calendar year end. Adjusted statutory net income is defined for this purpose to be the greater of statutory net income, net of realized investment gains, for the calendar year preceding the date of the dividend or statutory net income, net of realized investment gains, for the three calendar years preceding the date of the dividend less dividends paid within the first two of the preceding three calendar years. The OCI recognizes only statutory accounting practices prescribed or 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 lowered. For the year ended December 31, 2015, MGIC’s statutory net income was reduced by $444 million to account for the increase in contingency reserves. The NAIC previously announced that it plans to revise the minimum capital and surplus requirements for mortgage insurers that are provided for in its Mortgage Guaranty Insurance Model Act. A working group of state regulators is drafting the revisions, although no date has been established by which the NAIC must propose revisions to such requirements. Depending on the scope of revisions made by the NAIC, MGIC may be prevented from writing new business in the jurisdictions adopting such revisions. 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 another 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 insurance in force 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.

New Accounting Pronouncements (

New Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	Adopted Accounting Standards Presentation of Debt Issuance Costs In April 2015, the Financial Accounting Standards Board (“FASB”) issued updated guidance related to the presentation of debt issuance costs. The new standard requires the presentation of debt issuance costs in the balance sheet as a deduction from the carrying amount of the related debt liability instead of a deferred charge, consistent with the treatment of debt discounts. The updated guidance was effective for reporting periods beginning after December 15, 2015. The adoption of this guidance as of March 31, 2016 has been applied retrospectively to prior periods. See Note 3 - “Debt” for the reclassification made to our consolidated balance sheet as of December 31, 2015. The adoption of this guidance had no impact on our statements of operations or retained earnings. Accounting for Share-Based Compensation When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period In June 2014, the FASB issued updated guidance to resolve diversity in practice concerning employee shared-based compensation that contains performance targets that could be achieved after the requisite service period. No explicit guidance on how to account for these types of performance share-based compensation awards existed prior to this update. The updated guidance requires that a performance target that affects vesting and that can be achieved after the requisite service period be treated as a performance condition. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which service has been rendered. If the performance target becomes probable of being achieved before the end of the service period, the remaining unrecognized compensation cost for which requisite service has not yet been rendered is recognized prospectively over the remaining service period. The total amount of compensation cost recognized during and after the service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The updated guidance was effective for reporting periods after December 15, 2015. The adoption of this guidance as of March 31, 2016, with application to awards granted during the first quarter of 2016, is not expected to have a material impact on our consolidated financial statements. Prospective Accounting Standards Improvements to Employee Share-Based Compensation Accounting In March 2016, the FASB issued updated guidance that simplifies several aspects of the accounting for employee share-based compensation including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. The updated guidance requires that, prospectively, all tax effects related to share-based compensation be made through the statement of operations at the time of settlement as opposed to excess tax benefits being recognized in paid-in capital under the current guidance. The updated guidance also removes the requirement to delay recognition of a tax benefit until it reduces current taxes payable. This change is required to be applied on a modified retrospective basis, with a cumulative effect adjustment to opening retained earnings. Additionally, all tax related cash flows resulting from share-based compensation are to be reported as operating activities on the statement of cash flows, a change from the existing requirement to present tax benefits as an inflow from financing activities and an outflow from operating activities. Finally, for tax withholding purposes, entities will be allowed to withhold an amount of shares up to the employee’s maximum individual tax rate (as opposed to the minimum statutory tax rate) in the relevant jurisdiction without resulting in liability classification of the award. The change in withholding requirements will be applied on a modified retrospective approach. The updated guidance is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted in any interim or annual period. We are currently evaluating the impacts the adoption of this guidance will have on our consolidated financial statements. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued updated guidance to address the recognition, measurement, presentation, and disclosure of certain financial instruments. The updated guidance requires equity investments, except those accounted for under the equity method of accounting, that have a readily determinable fair value to be measured at fair value with changes in fair value recognized in net income. Equity investments that do not have readily determinable fair values may be remeasured at fair value either upon the occurrence of an observable price change or upon identification of an impairment. A qualitative assessment for impairment is required for equity investments without readily determinable fair values. The updated guidance also eliminates the requirement to disclose the method and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost on the balance sheet. The updated guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods and will require recognition of a cumulative effect adjustment at adoption. We do not currently expect the adoption of this guidance to impact our consolidated financial position or liquidity. Disclosures about Short-Duration Contracts In May 2015, the FASB issued updated guidance requiring expanded disclosures for insurance entities that issue short-duration contracts. The expanded disclosures are designed to provide additional insight into an insurance entity’s ability to underwrite and anticipate costs associated with claims. The disclosures include information about incurred and paid claims development, on a net of reinsurance basis, for the number of years claims incurred typically remain outstanding, not to exceed ten years. Each period presented in the disclosure about claims development that precedes the current reporting periods is considered supplementary information. The expanded disclosures also include more transparent information about significant changes in methodologies and assumptions used to estimate claims, and the timing, frequency, and severity of claims. The disclosures required by this update are effective for annual periods beginning after December 31, 2015, and interim periods within annual periods beginning after December 31, 2016, and is to be applied retrospectively. We are evaluating the applicability and impact, if any, of the new disclosure requirements.

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Schedule of impact resulting from reclassification of debt issuance costs	The impact of the reclassification of debt issuance costs on our outstanding debt obligations as of December 31, 2015 is as follows. December 31, 2015 (In millions) As previously reported Adjustment As Adjusted Convertible Senior Notes, interest at 5% per annum, due May 2017 $ 333.5 $ (2.0 ) $ 331.5 Convertible Senior Notes, interest at 2% per annum, due April 2020 500.0 (9.2 ) 490.8 Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063 389.5 — 389.5 Total long-term debt $ 1,223.0 $ (11.2 ) $ 1,211.8
Long-term debt	The carrying amount of our debt obligations as of March 31, 2016 and December 31, 2015 (as adjusted) was as follows. (In millions) March 31, December 31, FHLB Advance, interest at 1.91% per annum, due February 2023 $ 155.0 $ — Convertible Senior Notes, interest at 5% per annum, due May 2017 (1) 194.3 331.5 Convertible Senior Notes, interest at 2% per annum, due April 2020 (2) (3) 491.3 490.8 Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063 (4) 256.9 389.5 Total long-term debt $ 1,097.5 $ 1,211.8 (1) Convertible at any time prior to maturity at the holder’s option, at an initial conversion rate, which is subject to adjustment, of 74.4186 shares per $1,000 principal amount, representing an initial conversion price of approximately $13.44 per share. (2) Prior to January 1, 2020, the 2% Convertible Senior Notes are convertible only upon satisfaction of one or more conditions. One such condition is that during any calendar quarter commencing after March 31, 2014, the last reported sale price of our common stock for each of at least 20 trading days during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter be greater than or equal to 130% of the applicable conversion price on each applicable trading day. The 2% Notes are convertible at an initial conversion rate, which is subject to adjustment, of 143.8332 shares per $1,000 principal amount, representing an initial conversion price of approximately $6.95 per share. 130% of such conversion price is $9.03 . On or after January 1, 2020, holders may convert their notes irrespective of satisfaction of the conditions. (3) Prior to April 10, 2017, the notes will not be redeemable. On any business day on or after April 10, 2017 we may redeem for cash all or part of the notes, at our option, at a redemption rate equal to 100% of the principal amount of the notes being redeemed, plus any accrued and unpaid interest, if the closing sale price of our common stock exceeds 130% of the then prevailing conversion price of the notes for each of at least 20 of the 30 consecutive trading days preceding notice of the redemption. (4) Convertible at any time prior to maturity at the holder’s option, at an initial conversion rate, which is subject to adjustment, of 74.0741 shares per $1,000 principal amount, representing an initial conversion price of approximately $13.50 per share. If a holder elects to convert their debentures, deferred interest owed on the 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. In lieu of issuing shares of common stock upon conversion of the debentures, we may, at our option, make a cash payment to converting holders for all or some of the shares of our common stock otherwise issuable upon conversion.
Interest payments made	Interest payments on our debt obligations appear below. Three Months Ended (In millions) 2016 2015 FHLB Advance, interest at 1.91% per annum, due February 2023 $ 0.2 $ — Convertible Senior Notes, interest at 5% per annum, due May 2017 1.8 — Convertible Senior Notes, interest at 2% per annum, due April 2020 — — Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063 4.3 — Total interest payments $ 6.3 $ —

Reinsurance (Tables)

Reinsurance (Tables)	3 Months Ended
	Mar. 31, 2016
Reinsurance Disclosures [Abstract]
Effect of all reinsurance agreements on premiums earned and losses incurred	The effect of all reinsurance agreements on premiums earned and losses incurred is as follows: Three Months Ended March 31, (In thousands) 2016 2015 Premiums earned: Direct $ 255,387 $ 245,748 Assumed 208 338 Ceded (34,254 ) (28,798 ) Net premiums earned $ 221,341 $ 217,288 Losses incurred: Direct $ 92,432 $ 88,036 Assumed 101 568 Ceded (7,521 ) (6,819 ) Net losses incurred $ 85,012 $ 81,785
Effect of reinsurance agreement	A summary of our quota share reinsurance agreements, excluding captive agreements, for the three months ended March 31, 2016 and 2015 appears as follows. Three Months Ended March 31, (In thousands) 2016 2015 2013 QSR Transaction Ceded premiums written, net of profit commission n/a $ 27,136 Ceded premiums earned, net of profit commission n/a 24,613 Ceded losses incurred n/a 4,873 Ceding commissions (2) n/a 10,122 Profit commission n/a 23,474 2015 QSR Transaction (Effective July 1, 2015) Ceded premiums written, net of profit commission (1) $ 31,666 n/a Ceded premiums earned, net of profit commission (1) 31,666 n/a Ceded losses incurred 8,513 n/a Ceding commissions (2) 11,576 n/a Profit commission 26,215 n/a (1) Effective July 1, 2015 premiums are ceded on an earned and received basis as defined in our 2015 QSR Transaction. (2) Ceding commissions are reported within Other underwriting and operating expenses, net on the consolidated statements of operations.

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Calculation of earnings (loss) per share	The following table reconciles the numerators and denominators used to calculate basic and diluted EPS and also indicates the number of antidilutive securities. Three months ended March 31, (In thousands, except per share data) 2016 2015 Basic earnings per share: Net income $ 69,191 $ 133,076 Weighted average common shares outstanding 340,144 339,107 Basic income per share $ 0.20 $ 0.39 Diluted earnings per share: Net income $ 69,191 $ 133,076 Interest expense, net of tax (1) : 2% Convertible Senior Notes due 2020 1,982 3,049 5% Convertible Senior Notes due 2017 2,678 4,692 9% Convertible Junior Subordinated Debentures due 2063 — 8,765 Diluted income available to common shareholders $ 73,851 $ 149,582 Weighted average shares - basic 340,144 339,107 Effect of dilutive securities: Unvested restricted stock units 1,679 2,569 2% Convertible Senior Notes due 2020 71,917 71,917 5% Convertible Senior Notes due 2017 17,625 25,674 9% Convertible Junior Subordinated Debentures due 2063 — 28,854 Weighted average shares - diluted 431,365 468,121 Diluted income per share $ 0.17 $ 0.32 Antidilutive securities (in millions) 23.3 — (1) Due to the valuation allowance recorded against deferred tax assets, the three months ended March 31, 2015 were not tax effected. The three months ended March 31, 2016 have been tax effected at a rate of 35%.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2016
Investments [Abstract]
Amortized cost, gross unrealized gains and losses and fair value of investments portfolio	The amortized cost, gross unrealized gains and losses and fair value of the investment portfolio at March 31, 2016 and December 31, 2015 are shown below. March 31, 2016 (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 $ 147,189 $ 2,474 $ (1,135 ) $ 148,528 Obligations of U.S. states and political subdivisions 1,854,959 60,677 (2,506 ) 1,913,130 Corporate debt securities 1,856,376 16,315 (18,484 ) 1,854,207 Asset-backed securities 110,241 176 (89 ) 110,328 Residential mortgage-backed securities 255,344 452 (5,155 ) 250,641 Commercial mortgage-backed securities 220,719 1,678 (1,701 ) 220,696 Collateralized loan obligations 61,350 25 (991 ) 60,384 Total debt securities 4,506,178 81,797 (30,061 ) 4,557,914 Equity securities 6,209 87 (7 ) 6,289 Total investment portfolio $ 4,512,387 $ 81,884 $ (30,068 ) $ 4,564,203 December 31, 2015 (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 $ 160,393 $ 2,133 $ (1,942 ) $ 160,584 Obligations of U.S. states and political subdivisions 1,766,407 33,410 (7,290 ) 1,792,527 Corporate debt securities 2,046,697 2,836 (44,770 ) 2,004,763 Asset-backed securities 116,764 56 (203 ) 116,617 Residential mortgage-backed securities 265,879 161 (8,392 ) 257,648 Commercial mortgage-backed securities 237,304 162 (3,975 ) 233,491 Collateralized loan obligations 61,345 3 (1,148 ) 60,200 Debt securities issued by foreign sovereign governments 29,359 2,474 (102 ) 31,731 Total debt securities 4,684,148 41,235 (67,822 ) 4,657,561 Equity securities 5,625 38 (18 ) 5,645 Total investment portfolio $ 4,689,773 $ 41,273 $ (67,840 ) $ 4,663,206 (1) At March 31, 2016 and December 31, 2015 , there were no other-than-temporary impairment losses recorded in other comprehensive income.
Amortized cost and fair values of debt securities by contractual maturity	The amortized cost and fair values of debt securities at March 31, 2016 , by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Because most asset-backed and mortgage-backed securities and collateralized loan obligations provide for periodic payments throughout their lives, they are listed below in separate categories. March 31, 2016 (In thousands) Amortized Cost Fair Value Due in one year or less $ 310,484 $ 311,202 Due after one year through five years 1,265,465 1,278,045 Due after five years through ten years 1,120,853 1,122,243 Due after ten years 1,161,722 1,204,375 $ 3,858,524 $ 3,915,865 Asset-backed securities 110,241 110,328 Residential mortgage-backed securities 255,344 250,641 Commercial mortgage-backed securities 220,719 220,696 Collateralized loan obligations 61,350 60,384 Total as of March 31, 2016 $ 4,506,178 $ 4,557,914
Aging of the fair values of securities in an unrealized loss position	For those securities in an unrealized loss position, the length of time the securities were in such a position, as measured by their month-end fair values, is as follows: March 31, 2016 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 $ 26,586 $ (1,094 ) $ 2,998 $ (41 ) $ 29,584 $ (1,135 ) Obligations of U.S. states and political subdivisions 105,443 (763 ) 60,616 (1,743 ) 166,059 (2,506 ) Corporate debt securities 350,566 (7,932 ) 348,277 (10,552 ) 698,843 (18,484 ) Asset-backed securities 29,107 (42 ) 11,019 (47 ) 40,126 (89 ) Residential mortgage-backed securities 14,548 (103 ) 204,585 (5,052 ) 219,133 (5,155 ) Commercial mortgage-backed securities 60,778 (925 ) 56,126 (776 ) 116,904 (1,701 ) Collateralized loan obligations — — 51,907 (991 ) 51,907 (991 ) Equity securities 91 — 209 (7 ) 300 (7 ) Total $ 587,119 $ (10,859 ) $ 735,737 $ (19,209 ) $ 1,322,856 $ (30,068 ) December 31, 2015 Less Than 12 Months 12 Months or Greater Total (In thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (In thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 60,548 $ (1,467 ) $ 1,923 $ (475 ) $ 62,471 $ (1,942 ) Obligations of U.S. states and political subdivisions 417,615 (6,404 ) 37,014 (886 ) 454,629 (7,290 ) Corporate debt securities 1,470,628 (38,519 ) 114,982 (6,251 ) 1,585,610 (44,770 ) Asset-backed securities 86,604 (173 ) 5,546 (30 ) 92,150 (203 ) Residential mortgage-backed securities 35,064 (312 ) 209,882 (8,080 ) 244,946 (8,392 ) Commercial mortgage-backed securities 134,488 (2,361 ) 69,927 (1,614 ) 204,415 (3,975 ) Collateralized loan obligations — — 51,750 (1,148 ) 51,750 (1,148 ) Debt securities issued by foreign sovereign governments 4,463 (102 ) — — 4,463 (102 ) Equity securities 355 (8 ) 171 (10 ) 526 (18 ) Total $ 2,209,765 $ (49,346 ) $ 491,195 $ (18,494 ) $ 2,700,960 $ (67,840 )
Net realized investment gains (losses) and OTTI on investments	The net realized investment gains on the investment portfolio are as follows: Three Months Ended (In thousands) 2016 2015 Realized investment gains (losses) on investments: Fixed maturities $ 3,054 $ 26,324 Equity securities 2 3 Net realized investment gains $ 3,056 $ 26,327 Three Months Ended (In thousands) 2016 2015 Realized investment gains (losses) on investments: Gains on sales $ 4,104 $ 27,206 Losses on sales (1,048 ) (879 ) Net realized investment gains $ 3,056 $ 26,327

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair value measurements for items measured at fair value	Fair value measurements for assets measured at fair value included the following as of March 31, 2016 and December 31, 2015 : March 31, 2016 (In thousands) Total 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 $ 148,528 $ 51,448 $ 97,080 $ — Obligations of U.S. states and political subdivisions 1,913,130 — 1,911,938 1,192 Corporate debt securities 1,854,207 — 1,854,207 — Asset-backed securities 110,328 — 110,328 — Residential mortgage-backed securities 250,641 — 250,641 — Commercial mortgage-backed securities 220,696 — 220,696 — Collateralized loan obligations 60,384 — 60,384 — Total debt securities 4,557,914 51,448 4,505,274 1,192 Equity securities (1) 6,289 2,868 — 3,421 Total investment portfolio $ 4,564,203 $ 54,316 $ 4,505,274 $ 4,613 Real estate acquired (2) $ 12,849 $ — $ — $ 12,849 December 31, 2015 (In thousands) Total 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 $ 160,584 $ 46,197 $ 114,387 $ — Obligations of U.S. states and political subdivisions 1,792,527 — 1,791,299 1,228 Corporate debt securities 2,004,763 — 2,004,763 — Asset-backed securities 116,617 — 116,617 — Residential mortgage-backed securities 257,648 — 257,648 — Commercial mortgage-backed securities 233,491 — 233,491 — Collateralized loan obligations 60,200 — 60,200 — Debt securities issued by foreign sovereign governments 31,731 31,731 — — Total debt securities 4,657,561 77,928 4,578,405 1,228 Equity securities (1) 5,645 2,790 — 2,855 Total investment portfolio $ 4,663,206 $ 80,718 $ 4,578,405 $ 4,083 Real estate acquired (2) $ 12,149 $ — $ — $ 12,149 (1) Equity securities in Level 3 are carried at cost, which approximates fair value. (2) Real estate acquired through claim settlement, which is held for sale, is reported in Other assets on the consolidated balance sheets.
Reconciliation of beginning and ending balance for assets and liabilities measured at fair value with significant unobservable inputs (level 3)	For assets measured at fair value using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances for the three months ended March 31, 2016 and 2015 is shown in the following tables. There were no transfers into or out of Level 3 in those periods and there were no losses included in earnings for those periods attributable to the change in unrealized losses on assets still held at the end of the applicable period. (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2015 $ 1,228 $ 2,855 $ 4,083 $ 12,149 Total realized/unrealized gains (losses): Included in earnings and reported as losses incurred, net — — — (293 ) Purchases — 3,091 3,091 12,267 Sales (36 ) (2,525 ) (2,561 ) (11,274 ) Balance at March 31, 2016 $ 1,192 $ 3,421 $ 4,613 $ 12,849 (In thousands) Debt Securities Equity Securities Total Investments Real Estate Acquired Balance at December 31, 2014 $ 1,846 $ 321 $ 2,167 $ 12,658 Total realized/unrealized gains (losses): Included in earnings and reported as losses incurred, net — — — (503 ) Purchases 7 — 7 10,797 Sales (62 ) — (62 ) (12,055 ) Balance at March 31, 2015 $ 1,791 $ 321 $ 2,112 $ 10,897
Carrying value and fair value of debt	March 31, 2016 (In thousands) Carrying Value Fair Value Financial liabilities: FHLB Advance due 2023 $ 155,000 $ 156,831 Convertible Senior Notes due 2017 194,319 203,771 Convertible Senior Notes due 2020 491,305 630,310 Convertible Junior Subordinated Debentures due 2063 256,872 292,754 Total Debt $ 1,097,496 $ 1,283,666 December 31, 2015 (In thousands) Carrying Value Fair Value Financial liabilities: Convertible Senior Notes due 2017 $ 331,546 $ 345,616 Convertible Senior Notes due 2020 490,755 701,955 Convertible Junior Subordinated Debentures due 2063 389,522 455,067 Total Debt $ 1,211,823 $ 1,502,638

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2016
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income	The pretax components of our other comprehensive income (loss) and the related income tax (expense) benefit for the three months ended March 31, 2016 and 2015 are included in the following table. Three Months Ended March 31, (In thousands) 2016 2015 Net unrealized holding gains arising during the period $ 78,383 $ 19,721 Income tax expense (27,556 ) (6,876 ) Valuation allowance (1) — 6,718 Net of taxes 50,827 19,563 Net changes in benefit plan assets and obligations (474 ) (700 ) Income tax benefit 166 245 Valuation allowance (1) — (245 ) Net of taxes (308 ) (700 ) Net changes in unrealized foreign currency translation adjustment (1,496 ) (3,102 ) Income tax benefit 521 1,088 Net of taxes (975 ) (2,014 ) Total other comprehensive income 76,413 15,919 Total income tax (expense) benefit, net of valuation allowance (26,869 ) 930 Total other comprehensive income, net of tax $ 49,544 $ 16,849 (1) See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets.
Reclassification out of accumulated other comprehensive income	The pretax and related income tax (expense) benefit components of the amounts reclassified from our accumulated other comprehensive loss to our consolidated statements of operations for the three months ended March 31, 2016 and 2015 are included in the following table. Three Months Ended March 31, (In thousands) 2016 2015 Reclassification adjustment for net realized gains (losses) included in net income (1) $ 612 $ 11,234 Income tax expense (92 ) (3,931 ) Valuation allowance (2) — 3,926 Net of taxes 520 11,229 Reclassification adjustment related to benefit plan assets and obligations (3) 474 700 Income tax expense (166 ) (245 ) Valuation allowance (2) — 245 Net of taxes 308 700 Total reclassifications 1,086 11,934 Total income tax expense, net of valuation allowance (258 ) (5 ) Total reclassifications, net of tax $ 828 $ 11,929 (1) Increases (decreases) Net realized investment gains on the consolidated statements of operations. (2) See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets. (3) Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations.
Accumulated other comprehensive income (loss)	Changes in our accumulated other comprehensive loss, including amounts reclassified from other comprehensive income (loss), for the three months ended March 31, 2016 are included in the table below. Three Months Ended March 31, 2016 (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 accumulated other comprehensive loss Balance at December 31, 2015, net of tax $ (17,148 ) $ (44,652 ) $ 920 $ (60,880 ) Other comprehensive income (loss) before reclassifications 51,347 — (975 ) 50,372 Less: Amounts reclassified from accumulated other comprehensive income (loss) 520 308 — 828 Balance at March 31, 2016, net of tax $ 33,679 $ (44,960 ) $ (55 ) $ (11,336 )

Benefit Plans (Tables)

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Components of net periodic benefit cost	The following table provides the components of net periodic benefit cost for the pension, supplemental executive retirement and other postretirement benefit plans: Three Months Ended March 31, (In thousands) Pension and Supplemental Executive Retirement Plans Other Postretirement Benefits 2016 2015 2016 2015 Service cost $ 2,163 $ 2,448 $ 175 $ 202 Interest cost 3,929 3,908 172 178 Expected return on plan assets (4,889 ) (5,295 ) (1,222 ) (1,248 ) Recognized net actuarial loss (gain) 1,361 1,209 — (35 ) Amortization of prior service cost (172 ) (211 ) (1,662 ) (1,662 ) Net periodic benefit cost (benefit) $ 2,392 $ 2,059 $ (2,537 ) $ (2,565 )

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Tax provision (benefit)	The effect of the change in valuation allowance on the provision for income taxes was as follows: Three months ended March 31, (In thousands) 2016 2015 Provision for income tax $ 34,497 $ 47,883 Change in valuation allowance — (44,498 ) Provision for income taxes $ 34,497 $ 3,385

Loss Reserves (Tables)

Loss Reserves (Tables)	3 Months Ended
	Mar. 31, 2016
Insurance Loss Reserves [Abstract]
Reconciliation of beginning and ending loss reserves	The following table provides a reconciliation of beginning and ending loss reserves for the three months ended March 31, 2016 and 2015 : Three months ended March 31, (In thousands) 2016 2015 Reserve at beginning of period $ 1,893,402 $ 2,396,807 Less reinsurance recoverable 44,487 57,841 Net reserve at beginning of period 1,848,915 2,338,966 Losses incurred: Losses and LAE incurred in respect of defaults related to: Current year 92,479 109,381 Prior years (1) (7,467 ) (27,596 ) Subtotal 85,012 81,785 Losses paid: Losses and LAE paid in respect of defaults related to: Current year 204 312 Prior years 221,457 231,230 Reinsurance terminations (2) (4 ) — Subtotal 221,657 231,542 Net reserve at end of period 1,712,270 2,189,209 Plus reinsurance recoverables 41,119 55,415 Reserve at end of period $ 1,753,389 $ 2,244,624 (1) A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves. (2) In a termination or commutation, the reinsurance agreement is cancelled, with no future premium ceded and funds for any incurred but unpaid losses transferred to us. The transferred funds result in an increase in our investment portfolio (including cash and cash equivalents) and a decrease in net losses paid (reduction in losses incurred). In addition, there is an offsetting decrease in the reinsurance recoverable (increase in losses incurred), and thus there is no net impact to losses incurred.
Prior year development of the reserves	The prior year development of the reserves in the first three months of 2016 and 2015 is reflected in the following table. Three months ended March 31, (In millions) 2016 2015 Decrease in estimated claim rate on primary defaults $ (26 ) $ (39 ) Increase in estimated severity on primary defaults 22 17 Change in estimates related to pool reserves, LAE reserves and reinsurance (3 ) (6 ) Total prior year loss development (1) $ (7 ) $ (28 ) (1) A negative number for prior year loss development indicates a redundancy of prior year loss reserves, and a positive number indicates a deficiency of prior year loss reserves
Rollforward of primary default inventory	A rollforward of our primary default inventory for the three months ended March 31, 2016 and 2015 appears in the following table. 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. Three months ended March 31, 2016 2015 Default inventory at beginning of period 62,633 79,901 New notices 16,731 18,896 Cures (19,053 ) (21,767 ) Paids (including those charged to a deductible or captive) (3,373 ) (4,573 ) Rescissions and denials (210 ) (221 ) Items removed from inventory resulting from settlements (1) (1,138 ) — Default inventory at end of period 55,590 72,236 (1) Includes 732 loans whose insurance was terminated by agreement to settle coverage on certain non-performing loans, and 406 loans for which we had previously suspended rescissions and that were included in a rescission settlement agreement. Both agreements became effective in the first quarter of 2016 and neither had a material financial impact in the quarter.
Aging of the primary default inventory	As of March 31, 2016 the percentage of loans in the inventory that have been in default for 12 or more consecutive months remained consistent compared with the prior year end and declined compared to one year prior, as shown in the following table. Historically as a default ages it becomes more likely to result in a claim. The percentage of loans that have been in default for 12 or more consecutive months and the number of loans in our primary claims received inventory have been affected by our suspended rescissions and the resolution of certain of those rescissions discussed below and in Note 5 – “Litigation and Contingencies.” March 31, 2016 December 31, 2015 March 31, 2015 Consecutive months in default 3 months or less 10,120 18 % 13,053 21 % 11,604 16 % 4 - 11 months 15,319 28 % 15,763 25 % 18,940 26 % 12 months or more (1) 30,151 54 % 33,817 54 % 41,692 58 % Total primary default inventory 55,590 100 % 62,633 100 % 72,236 100 % Primary claims received inventory included in ending default inventory 2,267 4 % 2,769 4 % 4,448 6 % (1) Approximately 49% , 50% , and 53% of the primary default inventory in default for 12 consecutive months or more has been in default for at least 36 consecutive months as of March 31, 2016 , December 31, 2015 , and March 31, 2015 , respectively.
Number of payments delinquent	The number of payments that a borrower is delinquent is shown in the table below. March 31, 2016 December 31, 2015 March 31, 2015 Number of payments delinquent 3 payments or less 16,864 30 % 20,360 33 % 19,159 27 % 4 - 11 payments 14,595 26 % 15,092 24 % 18,372 25 % 12 payments or more 24,131 44 % 27,181 43 % 34,705 48 % Total primary default inventory 55,590 100 % 62,633 100 % 72,236 100 %

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of stock-based compensation, activity	The number of shares granted to employees and the weighted average fair value per share during the periods presented were (shares in thousands): Three months ended March 31, 2016 2015 Shares Granted Weighted Average Share Fair Value Shares Granted Weighted Average Share Fair Value RSUs subject to performance conditions 1,257 $ 5.66 1,110 $ 8.98 RSUs subject only to service conditions 433 5.67 408 8.98

Debt (Details)

Debt (Details)		1 Months Ended	3 Months Ended
		Feb. 29, 2016USD ($)	Mar. 31, 2016USD ($)trading_day$ / sharesshares	Mar. 31, 2015USD ($)shares	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Antidilutive securities (in shares) | shares			23,300,000	0
Loss on debt extinguishment			$ 13,440,000	$ 0
Federal Home Loan Bank advances		$ 155,000,000
Federal Home Loan Bank, advances, interest rate		1.91%
Federal Home Loan Bank advances, collateral, value of principal, percent		102.00%
Convertible senior notes			685,624,000		$ 822,301,000
Convertible junior subordinated debentures			256,872,000		389,522,000
Total debt			1,097,500,000		1,211,800,000
Holding company cash and investments			265,000,000
Unrealized gain loss on holding company investments			$ 100,000
Modified duration of holding company investments			2 years 4 months 24 days
Interest payments made			$ 6,300,000	0
Scenario, Previously Reported
Debt Instrument [Line Items]
Total debt					1,223,000,000
Restatement Adjustment
Debt Instrument [Line Items]
Total debt					(11,200,000)
Adjustments for New Accounting Pronouncement | Long-term Debt
Debt Instrument [Line Items]
Deferred issuance costs reclassified					(11,200,000)
Adjustments for New Accounting Pronouncement | Other Assets
Debt Instrument [Line Items]
Deferred issuance costs reclassified					11,200,000
Convertible Senior Notes, interest at 5% per annum, due May 2017
Debt Instrument [Line Items]
Extinguishment of debt amount			138,300,000
Purchase price of debt purchased			$ 143,400,000
Antidilutive securities (in shares) | shares			10,300,000
Convertible senior notes					331,500,000
Total debt	[1]		$ 194,300,000		331,500,000
Conversion rate (in shares per $1,000 note) | shares			74.4186
Principal amount of notes used in determining conversion rate			$ 1,000
Initial conversion price (in dollars per share) | $ / shares			$ 13.44
Stated interest rate (in hundredths)			5.00%
Interest payments made			$ 1,800,000	0
Convertible Senior Notes, interest at 5% per annum, due May 2017 | Scenario, Previously Reported
Debt Instrument [Line Items]
Convertible senior notes					333,500,000
Convertible Senior Notes, interest at 5% per annum, due May 2017 | Restatement Adjustment
Debt Instrument [Line Items]
Convertible senior notes					(2,000,000)
Convertible Junior Debentures at 9% per annum, Due 2063
Debt Instrument [Line Items]
Extinguishment of debt amount		$ 132,700,000
Purchase price of debt purchased		$ 150,700,000
Antidilutive securities (in shares) | shares			9,800,000
Loss on debt extinguishment			$ 8,300,000
Reacquisition of convertible junior subordinated debentures-equity component			$ 9,800,000
Convertible junior subordinated debentures					389,500,000
Stated interest rate (in hundredths)			9.00%
Convertible Junior Debentures at 9% per annum, Due 2063 | Scenario, Previously Reported
Debt Instrument [Line Items]
Convertible junior subordinated debentures					389,500,000
Convertible Junior Debentures at 9% per annum, Due 2063 | Restatement Adjustment
Debt Instrument [Line Items]
Convertible junior subordinated debentures					0
FHLB Advance, interest at 1.91% per annum, due February 2023
Debt Instrument [Line Items]
Total debt			$ 155,000,000		0
Interest payments made			200,000	0
Convertible Senior Notes, interest at 2% per annum, due April 2020
Debt Instrument [Line Items]
Convertible senior notes					490,800,000
Total debt	[2],[3]		$ 491,300,000		490,800,000
Conversion rate (in shares per $1,000 note) | shares			143.8332
Principal amount of notes used in determining conversion rate			$ 1,000
Initial conversion price (in dollars per share) | $ / shares			$ 6.95
Stated interest rate (in hundredths)			2.00%
Threshold number of trading days | trading_day			20
Threshold consecutive trading days			30 days
Percentage of conversion price (in hundredths)			130.00%
Convertible debt, conversion price | $ / shares			$ 9.03
Redemption price, percentage (in hundredths)			100.00%
Interest payments made			$ 0	0
Convertible Senior Notes, interest at 2% per annum, due April 2020 | Scenario, Previously Reported
Debt Instrument [Line Items]
Convertible senior notes					500,000,000
Convertible Senior Notes, interest at 2% per annum, due April 2020 | Restatement Adjustment
Debt Instrument [Line Items]
Convertible senior notes					(9,200,000)
Convertible Junior Subordinated Debentures, interest at 9% per annum, due April 2063
Debt Instrument [Line Items]
Total debt	[4]		$ 256,900,000		$ 389,500,000
Conversion rate (in shares per $1,000 note) | shares			74.0741
Principal amount of notes used in determining conversion rate			$ 1,000
Initial conversion price (in dollars per share) | $ / shares			$ 13.50
Stated interest rate (in hundredths)			9.00%
Period preceding election to convert			5 days
Interest payments made			$ 4,300,000	$ 0
[1]	Convertible at any time prior to maturity at the holder’s option, at an initial conversion rate, which is subject to adjustment, of 74.4186 shares per $1,000 principal amount, representing an initial conversion price of approximately $13.44 per share.
[2]	Prior to April 10, 2017, the notes will not be redeemable. On any business day on or after April 10, 2017 we may redeem for cash all or part of the notes, at our option, at a redemption rate equal to 100% of the principal amount of the notes being redeemed, plus any accrued and unpaid interest, if the closing sale price of our common stock exceeds 130% of the then prevailing conversion price of the notes for each of at least 20 of the 30 consecutive trading days preceding notice of the redemption.
[3]	Prior to January 1, 2020, the 2% Convertible Senior Notes are convertible only upon satisfaction of one or more conditions. One such condition is that during any calendar quarter commencing after March 31, 2014, the last reported sale price of our common stock for each of at least 20 trading days during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter be greater than or equal to 130% of the applicable conversion price on each applicable trading day. The 2% Notes are convertible at an initial conversion rate, which is subject to adjustment, of 143.8332 shares per $1,000 principal amount, representing an initial conversion price of approximately $6.95 per share. 130% of such conversion price is $9.03. On or after January 1, 2020, holders may convert their notes irrespective of satisfaction of the conditions.
[4]	Convertible at any time prior to maturity at the holder’s option, at an initial conversion rate, which is subject to adjustment, of 74.0741 shares per $1,000 principal amount, representing an initial conversion price of approximately $13.50 per share. If a holder elects to convert their debentures, deferred interest owed on the 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. In lieu of issuing shares of common stock upon conversion of the debentures, we may, at our option, make a cash payment to converting holders for all or some of the shares of our common stock otherwise issuable upon conversion.

Reinsurance (Details)

Reinsurance (Details) - USD ($)		Jul. 01, 2015	Jun. 30, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Reinsurance Disclosures [Abstract]
Premiums earned - Direct				$ 255,387,000	$ 245,748,000
Premiums earned - Assumed				208,000	338,000
Premiums earned - Ceded				(34,254,000)	(28,798,000)
Net premiums earned				221,341,000	217,288,000
Losses incurred - Direct				92,432,000	88,036,000
Losses incurred - Assumed				101,000	568,000
Losses incurred - Ceded				(7,521,000)	(6,819,000)
Net losses incurred				85,012,000	81,785,000
Premiums Written and Earned [Abstract]
Ceded premiums written, net of profit commission				34,218,000	31,294,000
Premiums earned - Ceded				34,254,000	28,798,000
Losses incurred - Ceded				7,521,000	6,819,000
Reinsurance recoverable on loss reserves				$ 41,119,000	55,415,000	$ 44,487,000	$ 57,841,000
Period of existing captive reinsurance agreement			10 years	10 years
Reinsurance recoverable on loss reserves related to captive agreements				$ 23,000,000		34,000,000
Fair value of trust fund assets under captive agreements				123,000,000		137,000,000
Quota Share Reinsurance Agreement, 2013
Reinsurance Disclosures [Abstract]
Premiums earned - Ceded					(24,613,000)
Losses incurred - Ceded					(4,873,000)
Premiums Written and Earned [Abstract]
Ceded premiums written, net of profit commission					27,136,000
Premiums earned - Ceded					24,613,000
Losses incurred - Ceded					4,873,000
Ceding commissions	[1]				10,122,000
Profit commission					$ 23,474,000
Quota Share Reinsurance Agreement, 2015
Reinsurance Disclosures [Abstract]
Premiums earned - Ceded	[2]			(31,666,000)
Losses incurred - Ceded				(8,513,000)
Effects of Reinsurance [Line Items]
Contingent termination fee		$ 0
Threshold for private mortgage insurer eligibility requirements for termination election		90.00%
Quota share for all policies covered		30.00%
Ceding commission, percentage		20.00%
Loss ratio threshold for profit commissions		60.00%
Premiums Written and Earned [Abstract]
Ceded premiums written, net of profit commission	[2]			31,666,000
Premiums earned - Ceded	[2]			31,666,000
Losses incurred - Ceded				8,513,000
Ceding commissions	[1]			11,576,000
Profit commission				26,215,000
Reinsurance recoverable on loss reserves				$ 18,000,000		$ 11,000,000
[1]	Ceding commissions are reported within Other underwriting and operating expenses, net on the consolidated statements of operations.
[2]	Effective July 1, 2015 premiums are ceded on an earned and received basis as defined in our 2015 QSR Transaction.

Litigation and Contingencies (D

Litigation and Contingencies (Details) $ in Thousands	1 Months Ended		3 Months Ended	6 Months Ended	12 Months Ended		40 Months Ended
	Jun. 30, 2015	Dec. 31, 2011lawsuit	Mar. 31, 2016USD ($)	Jun. 30, 2009	Dec. 31, 2015USD ($)	Dec. 31, 2013USD ($)	Mar. 31, 2015case
Curtailments [Abstract]
Average paid claim reduction due to curtailments (in hundredths)			5.10%		6.70%
Claims resolved by rescissions [Abstract]
Percentage of claims received in a quarter resolved by rescission, lower range limit (in hundredths)			5.00%
Percentage of claims received in a quarter resolved by rescission, upper range limit (in hundredths)				28.00%
Maximum exposure associated with other discussions and legal proceedings			$ 193,000
Class action complaint under RESPA [Abstract]
Period of existing captive reinsurance agreement	10 years		10 years
Civil penalty						$ 2,650
Other Legal Proceedings [Abstract]
Underwriting remedy expense					$ 1,000
Class Action Complaint Under RESPA | Pending Litigation
Class action complaint under RESPA [Abstract]
Number of lawsuits | lawsuit		12
Number of cases dismissed | case							12

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Basic earnings per share [Abstract]
Net income		$ 69,191	$ 133,076
Weighted average common shares outstanding (in shares)		340,144	339,107
Basic income per share (in dollars per share)		$ 0.20	$ 0.39
Diluted earnings per share [Abstract]
Net income		$ 69,191	$ 133,076
Effect of dilutive securities [Abstract]
Diluted income available to common shareholders		$ 73,851	$ 149,582
Weighted-average shares - Basic (in shares)		340,144	339,107
Weighted-average shares - Diluted (in shares)		431,365	468,121
Diluted income per share (in dollars per share)		$ 0.17	$ 0.32
Antidilutive securities (in shares)		23,300	0
Effective income tax rate		35.00%
Unvested Restricted Stock Units
Effect of dilutive securities [Abstract]
Dilutive securities (in shares)		1,679	2,569
Convertible Senior Notes, interest at 2% per annum, due April 2020
Effect of dilutive securities [Abstract]
Dilutive securities	[1]	$ 1,982	$ 3,049
Dilutive securities (in shares)		71,917	71,917
Stated interest rate		2.00%
Convertible Senior Notes, interest at 5% per annum, due May 2017
Effect of dilutive securities [Abstract]
Dilutive securities	[1]	$ 2,678	$ 4,692
Dilutive securities (in shares)		17,625	25,674
Antidilutive securities (in shares)		10,300
Stated interest rate		5.00%
Convertible Junior Debentures at 9% per annum, Due 2063
Effect of dilutive securities [Abstract]
Dilutive securities	[1]	$ 0	$ 8,765
Dilutive securities (in shares)		0	28,854
Antidilutive securities (in shares)		9,800
Stated interest rate		9.00%
[1]	Due to the valuation allowance recorded against deferred tax assets, the three months ended March 31, 2015 were not tax effected. The three months ended March 31, 2016 have been tax effected at a rate of 35%.

Investments (Details)

Investments (Details) $ in Thousands		1 Months Ended
		Feb. 29, 2016	Mar. 31, 2016USD ($)security	Dec. 31, 2015USD ($)security
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			$ 4,512,387	$ 4,689,773
Gross Unrealized Gains			81,884	41,273
Gross Unrealized Losses			(30,068)	(67,840)	[1]
Fair Value			4,564,203	4,663,206
Federal Home Loan Bank advances, collateral, value of principal, percent		102.00%
FHLB advance collateral			164,600
Gross accumulated unrealized gain (losses) on available-for-sale securities			(30,100)	(67,800)
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			587,119	2,209,765
12 months or greater			735,737	491,195
Total investment portfolio			1,322,856	2,700,960
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(10,859)	(49,346)
12 months or greater			(19,209)	(18,494)
Total investment portfolio			$ (30,068)	$ (67,840)
Number of securities in unrealized loss position | security			316	303
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			$ 147,189	$ 160,393
Gross Unrealized Gains			2,474	2,133
Gross Unrealized Losses	[1]		(1,135)	(1,942)
Fair Value			148,528	160,584
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			26,586	60,548
12 months or greater			2,998	1,923
Total investment portfolio			29,584	62,471
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(1,094)	(1,467)
12 months or greater			(41)	(475)
Total investment portfolio			(1,135)	(1,942)
Obligations of U.S. states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			1,854,959	1,766,407
Gross Unrealized Gains			60,677	33,410
Gross Unrealized Losses	[1]		(2,506)	(7,290)
Fair Value			1,913,130	1,792,527
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			105,443	417,615
12 months or greater			60,616	37,014
Total investment portfolio			166,059	454,629
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(763)	(6,404)
12 months or greater			(1,743)	(886)
Total investment portfolio			(2,506)	(7,290)
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			1,856,376	2,046,697
Gross Unrealized Gains			16,315	2,836
Gross Unrealized Losses	[1]		(18,484)	(44,770)
Fair Value			1,854,207	2,004,763
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			350,566	1,470,628
12 months or greater			348,277	114,982
Total investment portfolio			698,843	1,585,610
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(7,932)	(38,519)
12 months or greater			(10,552)	(6,251)
Total investment portfolio			(18,484)	(44,770)
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			110,241	116,764
Gross Unrealized Gains			176	56
Gross Unrealized Losses	[1]		(89)	(203)
Fair Value			110,328	116,617
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			29,107	86,604
12 months or greater			11,019	5,546
Total investment portfolio			40,126	92,150
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(42)	(173)
12 months or greater			(47)	(30)
Total investment portfolio			(89)	(203)
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			255,344	265,879
Gross Unrealized Gains			452	161
Gross Unrealized Losses	[1]		(5,155)	(8,392)
Fair Value			250,641	257,648
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			14,548	35,064
12 months or greater			204,585	209,882
Total investment portfolio			219,133	244,946
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(103)	(312)
12 months or greater			(5,052)	(8,080)
Total investment portfolio			(5,155)	(8,392)
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			220,719	237,304
Gross Unrealized Gains			1,678	162
Gross Unrealized Losses	[1]		(1,701)	(3,975)
Fair Value			220,696	233,491
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			60,778	134,488
12 months or greater			56,126	69,927
Total investment portfolio			116,904	204,415
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			(925)	(2,361)
12 months or greater			(776)	(1,614)
Total investment portfolio			(1,701)	(3,975)
Collateralized loan obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			61,350	61,345
Gross Unrealized Gains			25	3
Gross Unrealized Losses	[1]		(991)	(1,148)
Fair Value			60,384	60,200
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			0	0
12 months or greater			51,907	51,750
Total investment portfolio			51,907	51,750
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			0	0
12 months or greater			(991)	(1,148)
Total investment portfolio			(991)	(1,148)
Debt securities issued by foreign sovereign governments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost				29,359
Gross Unrealized Gains				2,474
Gross Unrealized Losses	[1]			(102)
Fair Value				31,731
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months				4,463
12 months or greater				0
Total investment portfolio				4,463
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months				(102)
12 months or greater				0
Total investment portfolio				(102)
Total debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			4,506,178	4,684,148
Gross Unrealized Gains			81,797	41,235
Gross Unrealized Losses			(30,061)	(67,822)	[1]
Fair Value			4,557,914	4,657,561
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			6,209	5,625
Gross Unrealized Gains			87	38
Gross Unrealized Losses	[1]		(7)	(18)
Fair Value			6,289	5,645
Continuous Unrealized Loss Portion, Fair Value [Abstract]
Less than 12 months			91	355
12 months or greater			209	171
Total investment portfolio			300	526
Continuous Unrealized Loss Portion, Unrealized Loses [Abstract]
Less than 12 months			0	(8)
12 months or greater			(7)	(10)
Total investment portfolio			$ (7)	$ (18)
[1]	At March 31, 2016 and December 31, 2015, there were no other-than-temporary impairment losses recorded in other comprehensive income.

Investments - Amortized Cost an

Investments - Amortized Cost and Fair Values of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Maturities, Amortized Cost [Abstract]
Due in one year or less	$ 310,484
Due after one year through five years	1,265,465
Due after five years through ten years	1,120,853
Due after ten years	1,161,722
Total debt securities with sngle maturity date, amortized cost	3,858,524
Total at end of period	4,506,178	$ 4,684,148
Maturities, Fair Value [Abstract]
Due in one year or less	311,202
Due after one year through five years	1,278,045
Due after five years through ten years	1,122,243
Due after ten years	1,204,375
Total debt securities with single maturity date, fair value	3,915,865
Total at end of period	4,557,914	$ 4,657,561
Asset-backed securities
Maturities, Amortized Cost [Abstract]
Total debt securities without single maturity date, amortized cost	110,241
Maturities, Fair Value [Abstract]
Total debt securities without single maturity date, fair value	110,328
Residential mortgage-backed securities
Maturities, Amortized Cost [Abstract]
Total debt securities without single maturity date, amortized cost	255,344
Maturities, Fair Value [Abstract]
Total debt securities without single maturity date, fair value	250,641
Commercial mortgage-backed securities
Maturities, Amortized Cost [Abstract]
Total debt securities without single maturity date, amortized cost	220,719
Maturities, Fair Value [Abstract]
Total debt securities without single maturity date, fair value	220,696
Collateralized loan obligations
Maturities, Amortized Cost [Abstract]
Total debt securities without single maturity date, amortized cost	61,350
Maturities, Fair Value [Abstract]
Total debt securities without single maturity date, fair value	$ 60,384

Investments - Gain (Loss) on In

Investments - Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses) on investments	$ 3,056	$ 26,327
Gross realized gains, gross realized losses and impairment losses [Abstract]
Gains on sales	4,104	27,206
Losses on sales	(1,048)	(879)
Net realized investment gains	3,056	26,327
Fixed maturities
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses) on investments	3,054	26,324
Gross realized gains, gross realized losses and impairment losses [Abstract]
Net realized investment gains	3,054	26,324
Equity securities
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses) on investments	2	3
Gross realized gains, gross realized losses and impairment losses [Abstract]
Net realized investment gains	$ 2	$ 3

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
State premium tax credit investments, average maturity		2 years
Annual average discount rate (in hundredths)		7.20%
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities and obligations of U.S. government corporations and agencies		$ 148,528	$ 160,584
Obligations of U.S. states and political subdivisions		1,913,130	1,792,527
Corporate debt securities		1,854,207	2,004,763
Asset-backed securities		110,328	116,617
Residential mortgage-backed securities		250,641	257,648
Commercial mortgage-backed securities		220,696	233,491
Collateralized loan obligations		60,384	60,200
Debt securities issued by foreign sovereign governments			31,731
Total debt securities		4,557,914	4,657,561
Equity securities	[1]	6,289	5,645
Total investment portfolio		4,564,203	4,663,206
Real estate acquired	[2]	12,849	12,149
Carrying Value
Debt [Abstract]
FHLB Advance due 2023		155,000
Convertible Senior Notes due 2017		194,319	331,546
Convertible Senior Notes due 2020		491,305	490,755
Convertible Junior Subordinated Debentures due 2063		256,872	389,522
Total Debt		1,097,496	1,211,823
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities and obligations of U.S. government corporations and agencies		51,448	46,197
Obligations of U.S. states and political subdivisions		0	0
Corporate debt securities		0	0
Asset-backed securities		0	0
Residential mortgage-backed securities		0	0
Commercial mortgage-backed securities		0	0
Collateralized loan obligations		0	0
Debt securities issued by foreign sovereign governments			31,731
Total debt securities		51,448	77,928
Equity securities	[1]	2,868	2,790
Total investment portfolio		54,316	80,718
Real estate acquired	[2]	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities and obligations of U.S. government corporations and agencies		97,080	114,387
Obligations of U.S. states and political subdivisions		1,911,938	1,791,299
Corporate debt securities		1,854,207	2,004,763
Asset-backed securities		110,328	116,617
Residential mortgage-backed securities		250,641	257,648
Commercial mortgage-backed securities		220,696	233,491
Collateralized loan obligations		60,384	60,200
Debt securities issued by foreign sovereign governments			0
Total debt securities		4,505,274	4,578,405
Equity securities	[1]	0	0
Total investment portfolio		4,505,274	4,578,405
Real estate acquired	[2]	0	0
Debt [Abstract]
FHLB Advance due 2023		156,831
Convertible Senior Notes due 2017		203,771	345,616
Convertible Senior Notes due 2020		630,310	701,955
Convertible Junior Subordinated Debentures due 2063		292,754	455,067
Total Debt		1,283,666	1,502,638
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities and obligations of U.S. government corporations and agencies		0	0
Obligations of U.S. states and political subdivisions		1,192	1,228
Corporate debt securities		0	0
Asset-backed securities		0	0
Residential mortgage-backed securities		0	0
Commercial mortgage-backed securities		0	0
Collateralized loan obligations		0	0
Debt securities issued by foreign sovereign governments			0
Total debt securities		1,192	1,228
Equity securities	[1]	3,421	2,855
Total investment portfolio		4,613	4,083
Real estate acquired	[2]	$ 12,849	$ 12,149
[1]	Equity securities in Level 3 are carried at cost, which approximates fair value.
[2]	Real estate acquired through claim settlement, which is held for sale, is reported in Other assets on the consolidated balance sheets.

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 1,228	$ 1,846
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	0	0
Purchases	0	7
Sales	(36)	(62)
Balance at end of period	1,228	1,846	$ 1,192	$ 1,791
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	2,855	321
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	0	0
Purchases	3,091	0
Sales	(2,525)	0
Balance at end of period	2,855	321	3,421	321
Total Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	4,083	2,167
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	0	0
Purchases	3,091	7
Sales	(2,561)	(62)
Balance at end of period	4,083	2,167	4,613	2,112
Real Estate Acquired
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	12,149	12,658
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	(293)	(503)
Purchases	12,267	10,797
Sales	(11,274)	(12,055)
Balance at end of period	$ 12,149	$ 12,658	$ 12,849	$ 10,897

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Components of Other Comprehensive Income (Loss) [Abstract]
Net unrealized holding (losses) gains arising during the period		$ 78,383	$ 19,721
Income tax expense		(27,556)	(6,876)
Valuation allowance	[1]	0	6,718
Net of taxes		50,827	19,563
Net changes in benefit plan assets and obligations		(474)	(700)
Income tax benefit		166	245
Valuation allowance	[1]	0	(245)
Net of taxes		(308)	(700)
Net changes in unrealized foreign currency translation adjustment		(1,496)	(3,102)
Income tax benefit		521	1,088
Net of taxes		(975)	(2,014)
Total other comprehensive income (loss)		76,413	15,919
Total income tax (expense) benefit, net of valuation allowance		(26,869)	930
Other comprehensive income (loss), net of tax		49,544	16,849
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications		103,688	136,461
Income tax expense		(34,497)	(47,883)
Valuation allowance		0	(44,498)
Total income tax expense, net of valuation allowance		(34,497)	(3,385)
Net income		69,191	133,076
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax		(60,880)
Other comprehensive loss before reclassifications		50,372
Less: Amounts reclassified from AOCL		828
Balance at end of period, net of tax		(11,336)
Net unrealized gains and losses on available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax		(17,148)
Other comprehensive loss before reclassifications		51,347
Less: Amounts reclassified from AOCL		520
Balance at end of period, net of tax		33,679
Net benefit plan assets and obligations recognized in shareholders' equity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax		(44,652)
Other comprehensive loss before reclassifications		0
Less: Amounts reclassified from AOCL		308
Balance at end of period, net of tax		(44,960)
Net unrealized foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period, net of tax		920
Other comprehensive loss before reclassifications		(975)
Less: Amounts reclassified from AOCL		0
Balance at end of period, net of tax		(55)
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications		1,086	11,934
Total income tax expense, net of valuation allowance		(258)	(5)
Net income		828	11,929
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	[2]	612	11,234
Income tax expense		(92)	(3,931)
Valuation allowance	[3]	0	3,926
Net income		520	11,229
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	[4]	474	700
Income tax expense		(166)	(245)
Valuation allowance	[3]	0	245
Net income		$ 308	$ 700
[1]	See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets.
[2]	Increases (decreases) Net realized investment gains on the consolidated statements of operations.
[3]	See Note 11 – “Income Taxes” for a discussion of the valuation allowance recorded against deferred tax assets.
[4]	Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations.

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Components of Net Periodic Benefit Cost [Abstract]
Estimated future employer contributions in current fiscal year	$ 11,400
Pension and Supplemental Executive Retirement Plans
Components of Net Periodic Benefit Cost [Abstract]
Service cost	2,163	$ 2,448
Interest cost	3,929	3,908
Expected return on plan assets	(4,889)	(5,295)
Recognized net actuarial loss (gain)	1,361	1,209
Amortization of prior service cost	(172)	(211)
Net periodic benefit cost (benefit)	2,392	2,059
Other Postretirement Benefits
Components of Net Periodic Benefit Cost [Abstract]
Service cost	175	202
Interest cost	172	178
Expected return on plan assets	(1,222)	(1,248)
Recognized net actuarial loss (gain)	0	(35)
Amortization of prior service cost	(1,662)	(1,662)
Net periodic benefit cost (benefit)	$ (2,537)	$ (2,565)

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2007	Dec. 31, 2015
Valuation Allowance [Line Items]
Number of years used in the cumulative income position calculation	3 years
Provision for income tax	$ 34,497	$ 47,883
Change in valuation allowance	0	(44,498)
Provision for income taxes	34,497	3,385
Net operating loss carryforwards, regular tax basis	1,900,000
Net operating loss carryforwards for computing the alternative minimum tax	1,000,000
Information regarding income tax examinations [Abstract]
Amount of IRS assessment for unpaid taxes and penalties related to REMIC issue	197,500
Estimate of federal interest that may be due	187,400
Amount of payment made related to the IRS assessment on the REMIC issue			$ 65,200
Amount of IRS assessment for unpaid taxes and penalties related to disallowance of carryback of 2009 net operating loss	261,400
Estimate of additional state income taxes and interest that may be due	49,300
Total amount of unrecognized tax benefits	107,400
Total amount of the unrecognized tax benefits that would affect our effective tax rate	94,100
Unrecognized tax benefits, accrued interest	$ 28,100			$ 27,800
Other Comprehensive Income (Loss)
Valuation Allowance [Line Items]
Change in valuation allowance		$ (6,500)

Loss Reserves (Details)

Loss Reserves (Details) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2016USD ($)loan	Mar. 31, 2015USD ($)loan	Dec. 31, 2015USD ($)loan	Mar. 31, 2016USD ($)loan	Dec. 31, 2015USD ($)loan	Mar. 31, 2015loan
Loss Reserve [Roll Forward]
Reserve at beginning of period		$ 1,893,402	$ 2,396,807	$ 2,396,807
Less reinsurance recoverable		44,487	57,841	57,841
Net reserve at beginning of period		1,848,915	2,338,966	2,338,966
Losses and LAE incurred in respect of defaults related to [Abstract]
Current year		92,479	109,381
Prior years	[1]	(7,467)	(27,596)
Subtotal		85,012	81,785
Losses and LAE paid in respect of defaults related to [Abstract]
Current year		204	312
Prior years		221,457	231,230
Reinsurance terminations	[2]	(4)	0
Subtotal		221,657	231,542
Net reserve at end of period		1,712,270	2,189,209	1,848,915
Plus reinsurance recoverables		41,119	55,415	44,487
Reserve at end of period		1,753,389	2,244,624	$ 1,893,402
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years	[1]	(7,467)	(27,596)
Prior years		$ 221,457	$ 231,230
Premium refund liability, expected claim payments					$ 99,000	$ 102,000
Primary Default Inventory [Roll Forward]
Default inventory at the beginning of period | loan		62,633	79,901	79,901
New notices | loan		16,731	18,896
Cures | loan		(19,053)	(21,767)
Paids (including those charged to a deductible or captive) | loan		(3,373)	(4,573)
Rescissions and denials | loan		(210)	(221)
Items removed from inventory resulting from settlements (1) | loan	[3]	(1,138)	0
Default inventory at end of period | loan		55,590	72,236	62,633
Loans whose insurance was terminated by agreement to settle coverage | loan		732
Number of loans with previously suspended rescissions included in rescission settlement agreement | loan		406
Pool insurance notice inventory [Abstract]
Historical average period for uncured default to develop into paid claim		12 months
Percent of default inventory in default for more than 36 months		49.00%	53.00%	50.00%
Pool insurance notice inventory (in number of loans) | loan					2,247	2,739	3,350
Aging of the Primary Default Inventory [Abstract]
3 months or less | loan					10,120	13,053	11,604
3 months or less (in hundredths)					18.00%	21.00%	16.00%
4 - 11 months | loan					15,319	15,763	18,940
4 - 11 months (in hundredths)					28.00%	25.00%	26.00%
12 months or more | loan	[4]				30,151	33,817	41,692
12 months or more (in hundredths)	[4]				54.00%	54.00%	58.00%
Total primary default inventory | loan		62,633	79,901	79,901	55,590	62,633	72,236
Total primary default inventory (in hundredths)					100.00%	100.00%	100.00%
Primary claims received inventory included in ending default inventory | loan					2,267	2,769	4,448
Primary claims received inventory included in ending default inventory (in hundredths)					4.00%	4.00%	6.00%
Number of payments delinquent [Abstract]
3 payments or less | loan					16,864	20,360	19,159
3 payments or less (in hundredths)					30.00%	33.00%	27.00%
4 - 11 payments | loan					14,595	15,092	18,372
4 - 11 payments (in hundredths)					26.00%	24.00%	25.00%
12 payments or more | loan					24,131	27,181	34,705
12 payments or more (in hundredths)					44.00%	43.00%	48.00%
Total primary default inventory | loan		62,633	79,901	79,901	55,590	62,633	72,236
Total primary default inventory (in hundredths)					100.00%	100.00%	100.00%
Premium refund liability, expected future rescissions					$ 5,000	$ 7,000
Decrease in estimated claim rate on primary defaults
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years		$ (26,000)	$ (39,000)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		$ (26,000)	$ (39,000)
Percentage of prior year default inventory resolved (in hundredths)		28.00%	24.00%
Increase in estimated severity on primary defaults
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years		$ 22,000	$ 17,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		22,000	17,000
Change in estimates related to pool reserves, LAE reserves and reinsurance
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years		(3,000)	(6,000)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		(3,000)	(6,000)
Change in estimates related to disputes on claims paying practices and IBNR
Losses and LAE incurred in respect of defaults related to [Abstract]
Prior years			20,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years			$ 20,000
Settlements For Claims Paying Practices And Nonperforming Loan Sale
Losses and LAE paid in respect of defaults related to [Abstract]
Prior years		47,000
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years		$ 47,000
[1]	A negative number for prior year losses incurred indicates a redundancy of prior year loss reserves.
[2]	In a termination or commutation, the reinsurance agreement is cancelled, with no future premium ceded and funds for any incurred but unpaid losses transferred to us. The transferred funds result in an increase in our investment portfolio (including cash and cash equivalents) and a decrease in net losses paid (reduction in losses incurred). In addition, there is an offsetting decrease in the reinsurance recoverable (increase in losses incurred), and thus there is no net impact to losses incurred.
[3]	Includes 732 loans whose insurance was terminated by agreement to settle coverage on certain non-performing loans, and 406 loans for which we had previously suspended rescissions and that were included in a rescission settlement agreement. Both agreements became effective in the first quarter of 2016 and neither had a material financial impact in the quarter.
[4]	Approximately 49%, 50%, and 53% of the primary default inventory in default for 12 consecutive months or more has been in default for at least 36 consecutive months as of March 31, 2016, December 31, 2015, and March 31, 2015, respectively.

Shareholders' Equity (Details)

Shareholders' Equity (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)$ / sharesshares
Class of Warrant or Right [Line Items]
Common stock, beneficial ownership threshold to be considered an Acquiring Person (in hundredths)	5.00%
Shareholder rights accompanying each outstanding share of the company's common stock (in number of Rights) | shares	1
Purchase price (in dollars per share) | $ / shares	$ 45
Purchase price (in dollars per one-tenth share) | $ / shares	4.50
Redemption price (in dollars per Right) | $ / shares	$ 0.001
Common shares purchasable per Right (in shares) | shares	0.1
Rights
Class of Warrant or Right [Line Items]
Number of rights per outstanding share of common stock | shares	1
Period after public announcement that a person has become an acquirer	10 days
Period after a person announces a tender offer which would make them an acquirer	10 days
Convertible Junior Debentures at 9% per annum, Due 2063
Class of Warrant or Right [Line Items]
Reacquisition of convertible junior subordinated debentures-equity component | $	$ 9.8
Stated interest rate	9.00%

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
RSUs subject to performance conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	1,257	1,110
Weighted Average Share Fair Value (in dollars per share)	$ 5.66	$ 8.98
RSUs subject only to service conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	433	408
Weighted Average Share Fair Value (in dollars per share)	$ 5.67	$ 8.98
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

Capital Requirements (Details)

Capital Requirements (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016USD ($)jurisdiction	Dec. 31, 2015USD ($)
Statutory capital requirements [Abstract]
Number of jurisdictions with risk-to-capital requirements | jurisdiction	16
Maximum permitted risk-to-capital ratio commonly applied	25 to 1
Risk to capital ratio of combined insurance operations, including reinsurance affiliates, at end of period	13.8 to 1
Risk-to-capital ratio for combined insurance operations	13.8
Percentage of statutory policyholders surplus used to determine maximum allowable dividends	10.00%
Maximum
Statutory capital requirements [Abstract]
Risk-to-capital ratio	25
Mortgage Guaranty Insurance Corporation
Statutory capital requirements [Abstract]
Risk to capital ratio at end of period	12.3 to 1
Risk-to-capital ratio	12.3
Amount of policyholders position above or below required MPP	$ 1,100
Amount of required MPP	1,100
Dividends paid to the parent company	$ 16
Adjusted statutory net income measurement period	3 years
Adjusted statutory net income dividend payment measurement period	2 years
Reduction in statutory net income due to increase in contingency reserve		$ 444