MGIC Investment (MTG) 10-Q 31 Oct 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Oct. 27, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	1-10816
Entity Registrant Name	MGIC Investment Corp
Entity Incorporation, State or Country Code	WI
Entity Tax Identification Number	39-1486475
Entity Address, Address Line One	250 E. Kilbourn Avenue
Entity Address, City or Town	Milwaukee,
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53202
City Area Code	(414)
Local Phone Number	347-6480
Title of each class	Common stock
Trading Symbol	MTG
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		277,311,432
Entity Central Index Key	0000876437
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investment portfolio:
Fixed income, available-for-sale, at fair value (amortized cost 2023 - $6,130,009; 2022 - $5,926,785)	$ 5,581,537	$ 5,409,698
Equity securities, at fair value (cost 2023 - $15,998; 2022 - $15,924)	13,949	14,140
Other invested assets, at cost	850	850
Total investment portfolio	5,596,336	5,424,688
Cash and cash equivalents	266,543	327,384
Restricted cash and cash equivalents	8,582	5,529
Accrued investment income	58,499	55,178
Reinsurance recoverable on loss reserves	40,934	28,240
Reinsurance recoverable on paid losses	265	18,081
Premiums receivable	57,606	58,000
Home office and equipment, net	39,379	41,419
Deferred insurance policy acquisition costs	15,905	19,062
Deferred income taxes, net	132,030	124,769
Other assets	115,600	111,443
Total assets	6,331,679	6,213,793
Liabilities:
Loss reserves	525,528	557,988
Unearned premiums	165,093	195,289
Senior notes	642,828	641,724
Convertible junior subordinated debentures	0	21,086
Other liabilities	143,525	154,966
Total liabilities	1,476,974	1,571,053
Contingencies
Shareholders’ equity:
Common stock	371,353	371,353
Paid-in capital	1,799,624	1,798,842
Treasury stock at cost	(1,260,422)	(1,050,238)
Accumulated other comprehensive income (loss), net of tax	(496,895)	(481,511)
Retained earnings	4,441,045	4,004,294
Total shareholders’ equity	4,854,705	4,642,740
Total liabilities and shareholders’ equity	$ 6,331,679	$ 6,213,793

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 6,130,009	$ 5,926,785
Cost	$ 15,998	$ 15,924
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	371,353,000	371,353,000
Common stock, shares outstanding (in shares)	279,475,000	293,433,000
Treasury stock at cost (in shares)	91,878,000	77,920,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Premiums written:
Direct	$ 280,885	$ 279,317	$ 828,211	$ 830,646
Assumed	3,770	2,205	9,538	6,291
Ceded	(50,164)	(39,215)	(141,842)	(107,644)
Net premiums written	234,491	242,307	695,907	729,293
Decrease in unearned premiums, net	6,786	9,804	30,196	33,755
Net premiums earned	241,277	252,111	726,103	763,048
Investment income, net of expenses	55,375	42,549	156,938	121,116
Net gains (losses) on investments and other financial instruments	(695)	(3,258)	(13,380)	(8,776)
Other revenue	548	1,397	1,484	5,143
Total revenues	296,505	292,799	871,145	880,531
Losses and expenses:
Losses incurred, net	(77)	(105,054)	(11,322)	(223,426)
Amortization of deferred policy acquisition costs	2,802	3,179	7,889	8,901
Other underwriting and operating expenses, net	50,130	58,475	174,191	166,656
Loss on debt extinguishment	0	11,632	0	40,130
Interest expense	9,254	10,300	28,005	38,673
Total losses and expenses	62,109	(21,468)	198,763	30,934
Income before tax	234,396	314,267	672,382	849,597
Provision for income tax	51,552	64,642	143,937	175,691
Net income	$ 182,844	$ 249,625	$ 528,445	$ 673,906
Earnings per share:
Basic (in dollars per share)	$ 0.65	$ 0.82	$ 1.85	$ 2.18
Diluted (in dollars per share)	$ 0.64	$ 0.81	$ 1.83	$ 2.15
Weighted average common shares outstanding - basic (in shares)	281,757	302,622	286,184	309,097
Weighted average common shares outstanding - diluted (in shares)	285,600	307,194	289,924	315,029

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 182,844	$ 249,625	$ 528,445	$ 673,906
Other comprehensive income (loss), net of tax:
Change in unrealized investment gains and losses	(75,221)	(153,615)	(24,796)	(599,933)
Benefit plan adjustments	3,213	(16,172)	9,412	(15,289)
Other comprehensive income (loss), net of tax	(72,008)	(169,787)	(15,384)	(615,222)
Comprehensive income (loss)	$ 110,836	$ 79,838	$ 513,061	$ 58,684

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common stock	Paid-in capital	Treasury stock	Accumulated other comprehensive income (loss)	Retained earnings
Balance, beginning of period at Dec. 31, 2021		$ 371,353	$ 1,794,906	$ (675,265)	$ 119,697	$ 3,250,691
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			(20,537)	10,579
Equity compensation			17,674
Repurchase of common stock				(306,184)
Other comprehensive income (loss), net of tax	$ (615,222)				(615,222)
Net income	673,906					673,906
Cash dividends						(81,537)
Balance, end of period at Sep. 30, 2022	4,540,061	371,353	1,792,043	(970,870)	(495,525)	3,843,060
Balance, beginning of period at Jun. 30, 2022		371,353	1,791,380	(887,959)	(325,738)	3,623,983
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			(2,670)	1,400
Equity compensation			3,333
Repurchase of common stock				(84,311)
Other comprehensive income (loss), net of tax	(169,787)				(169,787)
Net income	249,625					249,625
Cash dividends						(30,548)
Balance, end of period at Sep. 30, 2022	4,540,061	371,353	1,792,043	(970,870)	(495,525)	3,843,060
Balance, beginning of period at Dec. 31, 2022	4,642,740	371,353	1,798,842	(1,050,238)	(481,511)	4,004,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends	(58,800)
Balance, end of period at Jun. 30, 2023		371,353	1,799,444	(1,192,783)	(424,887)	4,291,135
Balance, beginning of period at Dec. 31, 2022	4,642,740	371,353	1,798,842	(1,050,238)	(481,511)	4,004,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			(16,992)	9,746
Reduction in shareholders' equity due to debt conversion			(5,315)
Equity compensation			23,089
Repurchase of common stock				(219,930)
Other comprehensive income (loss), net of tax	(15,384)				(15,384)
Net income	528,445					528,445
Cash dividends						(91,694)
Balance, end of period at Sep. 30, 2023	4,854,705	371,353	1,799,624	(1,260,422)	(496,895)	4,441,045
Balance, beginning of period at Jun. 30, 2023		371,353	1,799,444	(1,192,783)	(424,887)	4,291,135
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			(80)	33
Reduction in shareholders' equity due to debt conversion			(5,315)
Equity compensation			5,575
Repurchase of common stock				(67,672)
Other comprehensive income (loss), net of tax	(72,008)				(72,008)
Net income	182,844					182,844
Cash dividends						(32,934)
Balance, end of period at Sep. 30, 2023	$ 4,854,705	$ 371,353	$ 1,799,624	$ (1,260,422)	$ (496,895)	$ 4,441,045

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income	$ 528,445	$ 673,906
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29,004	42,826
Deferred tax expense (benefit)	(3,172)	1,900
Equity compensation	23,089	17,674
Loss on debt extinguishment	0	40,130
Net (gains) losses on investments and other financial instruments	13,380	8,776
Change in certain assets and liabilities:
Accrued investment income	(3,321)	(965)
Reinsurance recoverable on loss reserves	(12,694)	20,521
Reinsurance recoverable on paid losses	17,816	36,061
Premium receivable	394	(1,114)
Deferred insurance policy acquisition costs	3,157	1,696
Profit commission receivable	10,337	(1,497)
Loss reserves	(32,460)	(280,152)
Unearned premiums	(30,196)	(33,755)
Return premium accrual	(5,900)	(9,200)
Current income taxes	(2,130)	3,140
Other, net	(9,033)	(36,154)
Net cash provided by (used in) operating activities	526,716	483,793
Cash flows from investing activities:
Purchases of investments	(1,220,219)	(544,224)
Proceeds from sales of investments	294,202	391,394
Proceeds from maturity of fixed income securities	686,552	536,194
Proceeds from sale of equipment	166	0
Additions to property and equipment	(1,455)	(2,402)
Net cash provided by (used in) investing activities	(240,754)	380,962
Cash flows from financing activities:
Conversion/purchase of 9% convertible junior debentures	(28,637)	(88,908)
Redemption of 5.75% senior notes	0	(242,296)
Repayment of FHLB Advance	0	(155,000)
Cash portion of loss on debt extinguishment	0	(39,445)
Repurchase of common stock	(216,693)	(303,060)
Dividends paid	(91,174)	(81,288)
Payment of withholding taxes related to share-based compensation net share settlement	(7,246)	(9,958)
Net cash provided by (used in) financing activities	(343,750)	(919,955)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents	(57,788)	(55,200)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	332,913	304,958
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$ 275,125	$ 249,758

Nature of Business and Basis of

Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2023
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. MGIC Assurance Corporation (“MAC”) and MGIC Indemnity Corporation (“MIC”), insurance subsidiaries of MGIC, provide insurance for certain mortgages under Fannie Mae and Freddie Mac (the “GSEs”) credit risk transfer programs. 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, 2022 included in our 2022 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 an interim period are not necessarily indicative of the results that may be expected for the year ending December 31, 2023. The substantial majority of our NIW has been for loans purchased by the GSEs. The current private mortgage insurer eligibility requirements ("PMIERs") of the GSEs include financial requirements, as well as business, quality control and certain transactional approval requirements. The financial requirements of the PMIERs require a mortgage insurer’s "Available Assets" (generally only the most liquid assets of an insurer) to equal or exceed its "Minimum Required Assets" (which are based on an insurer's book of risk in force, calculated from tables of factors with several risk dimensions). Based on our application of the PMIERs, as of September 30, 2023, MGIC’s Available Assets are in excess of its Minimum Required Assets; and MGIC is in compliance with the PMIERs and eligible to insure loans purchased by the GSEs. Subsequent events

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Significant Accounting Policies	Significant Accounting Policies Recent accounting and reporting developments Accounting standards and laws and regulations effective in 2023, or early adopted, and relevant to our financial statements are described below: Reference Rate Reform: ASU 2022-06 In March 2020, the FASB issued ASU 2020-04 to provide temporary optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform. It provided optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. In December 2022, the FASB issued ASU 2022-06, extending the election and application from March 12, 2020 through December 31, 2024 (originally December 31, 2022). Future elections of this standard will ease, if warranted, the requirements for accounting for the future effects of reference rate reform. We have evaluated the impact the discontinuance of LIBOR will have on our consolidated financial statements and have determined it will not have a material impact. Inflation Reduction Act On August 16, 2022, the Inflation Reduction Act (the “IRA”) was enacted and signed into law in the United States. The IRA includes provisions for a 15% corporate minimum tax and a 1% excise tax on net stock repurchases. Both of these taxes are effective in 2023. We do not expect these tax provisions to have a material impact on our consolidated financial results, including our annual estimated effective tax rate. The amount of the excise tax on the repurchase of corporate stock was immaterial for the nine months ended September 30, 2023.

Debt

Debt	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Debt	Debt Debt obligations The aggregate carrying values of our long-term debt obligations and their par values, if different, as of September 30, 2023 and December 31, 2022 are presented in table 3.1 below. Long-term debt obligations Table 3.1 (In thousands) September 30, 2023 December 31, 2022 5.25% Notes, due August 2028 (par value: $650 million) $ 642,828 $ 641,724 9% Debentures, due April 2063 — 21,086 Long-term debt, carrying value $ 642,828 $ 662,810 The 5.25% Senior Notes (5.25% Notes) is an obligation of our holding company, MGIC Investment Corporation. 2023 Transactions In the third quarter of 2023, under the terms of our 9% Convertible Junior Subordinated Debentures (“9% Debentures”), we exercised our option to redeem the outstanding principal of $21.1 million. The 9% Debentures were convertible into shares of MGIC common stock at a rate of 77.9620 shares per $1,000 principal amount. Prior to the redemption date, substantially all holders elected to convert into shares of common stock. Under the terms of the 9% Debentures, we paid cash of $28.6 million in lieu of issuing shares of common stock. The conversion of our 9% Debentures resulted in a $5.3 million reduction in our shareholders’ equity, net of tax and a reduction of 1.6 million potentially dilutive shares. See Note 7 - “Debt” in our Annual Report on Form 10-K for the year ended December 31, 2022 for additional information pertaining to our debt obligations, including the conversion feature on the 9% Debentures. As of September 30, 2023 we are in compliance with our debt covenants. Interest payments Interest payments for the nine months ended September 30, 2023 and 2022 were $35.1 million and $52.7 million, respectively.

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2023
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance We have in place reinsurance agreements executed under quota share reinsurance (“QSR”) transactions and excess-of-loss (“XOL”) transactions as discussed below. The effect of all of our reinsurance transactions on our consolidated statement of operations is shown in table 4.1 below. Reinsurance Table 4.1 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2023 2022 2023 2022 Premiums earned: Direct $ 287,640 $ 289,072 $ 858,310 $ 864,191 Assumed 3,801 2,254 9,635 6,501 Ceded - quota share reinsurance (1) (32,693) (19,348) (90,012) (56,721) Ceded - excess-of-loss reinsurance (17,471) (19,867) (51,830) (50,923) Total ceded (50,164) (39,215) (141,842) (107,644) Net premiums earned $ 241,277 $ 252,111 $ 726,103 $ 763,048 Losses incurred: Direct $ 6,627 $ (112,435) $ 2,044 $ (242,861) Assumed 20 21 (7) (340) Ceded - quota share reinsurance (6,724) 7,360 (13,359) 19,775 Losses incurred, net $ (77) $ (105,054) $ (11,322) $ (223,426) Other Reinsurance Impacts: Profit commission on quota share reinsurance (1) $ 30,698 $ 47,255 $ 97,218 $ 135,049 Ceding commission on quota share reinsurance 12,678 13,321 37,446 38,355 (1) Ceded premiums earned are shown net of profit commission. Quota share reinsurance We have entered into QSR Transactions with panels of third-party reinsurers to cede a fixed quota share percentage of premiums earned and received and losses incurred on insurance covered by the transactions. We receive the benefit of a ceding commission equal to 20% of premiums ceded before profit commission. We also receive the benefit of a profit commission through a reduction of premiums we cede. The profit commission varies inversely with the level of losses on a “dollar for dollar” basis and can be eliminated at annual loss ratios higher than we have experienced on our QSR Transactions. Each of our QSR Transactions typically have annual loss ratio caps of 300% and lifetime loss ratios of 200% . Table 4.2 below provides additional detail regarding our QSR Transactions. Quota Share Reinsurance Table 4.2 Quota Share Contract Covered Policy Years Quota Share % Annual Loss Ratio to Exhaust Profit Commission (1) Contractual Termination Date 2020 QSR 2020 12.5 % 62.0 % December 31, 2031 2020 QSR and 2021 QSR 2020 17.5 % 62.0 % December 31, 2032 2020 QSR and 2021 QSR 2021 17.5 % 61.9 % December 31, 2032 2021 QSR and 2022 QSR 2021 12.5 % 57.5 % December 31, 2032 2021 QSR and 2022 QSR 2022 15.0 % 57.5 % December 31, 2033 2022 QSR and 2023 QSR 2022 15.0 % 62.0 % December 31, 2033 2022 QSR and 2023 QSR 2023 15.0 % 62.0 % December 31, 2034 2023 QSR 2023 10.0 % 58.5 % December 31, 2034 Credit Union QSR 2020-2025 65.0 % 50.0 % December 31, 2039 (1) We will receive a profit commission provided the annual loss ratio on policies covered under the transaction remains below this ratio. We can elect to terminate the QSR Transactions under specified scenarios without penalty upon prior written notice, including if we will receive less than 90% (80% for the Credit Union QSR Transaction) of the full credit amount under the PMIERs, full financial statement credit or full credit under applicable regulatory capital requirements for the risk ceded in any required calculation period. Table 4.3 provides additional details regarding optional termination dates and optional reductions to our quota share percentage which can, in each case, be elected by us for a fee. Under the optional reduction to the quota share percentage, we may reduce our quota share percentage from the original percentage shown in table 4.2 to the percentage shown in table 4.3. Quota Share Reinsurance Table 4.3 Quota Share Contract Covered Policy Years Optional Termination Date (1) Optional Quota Share % Reduction Date (2) Optional Reduced Quota Share % 2020 QSR 2020 December 31, 2023 January 1, 2024 10.5% or 8% 2020 QSR and 2021 QSR 2020 December 31, 2023 January 1, 2024 14.5% or 12% 2020 QSR and 2021 QSR 2021 December 31, 2023 January 1, 2024 14.5% or 12% 2021 QSR and 2022 QSR 2021 December 31, 2023 January 1, 2024 10.5% or 8% 2021 QSR and 2022 QSR 2022 December 31, 2024 January 1, 2024 12.5% or 10% 2022 QSR and 2023 QSR 2022 December 31, 2024 January 1, 2024 12.5% or 10% 2022 QSR and 2023 QSR 2023 December 31, 2025 July 1, 2024 12.5% or 10% 2023 QSR 2023 December 31, 2025 July 1, 2024 8% or 7% (1) We can elect early termination of the QSR Transaction beginning on this date, and semi-annually thereafter. (2) We can elect to reduce the quota share percentage beginning on this date, and semi-annually thereafter. We have elected to terminate our 2020 QSR Transaction effective December 31, 2023 and will incur an early termination fee in the fourth quarter of approximately $5 million. We agreed to terms on a 30% QSR Transaction with a group of unaffiliated reinsurers covering most of our new insurance written in 2024. Under the terms of our QSR Transactions, ceded premiums earned, ceding commissions, profit commission, and ceded paid loss and LAE are settled net on a quarterly basis. The ceded premiums earned 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 QSR Transactions was $40.9 million as of September 30, 2023 and $28.2 million as of December 31, 2022. The reinsurance recoverable balance is secured by funds on deposit from reinsurers (which does not include letters of credit), the minimum amount of which is based on the greater of 1) a reinsurer's funding requirements under PMIERs or 2) ceded reserves and unpaid losses. Each of the reinsurers under our QSR Transactions described above has an insurer financial strength rating of A- or better (or a comparable rating) by Standard and Poor's Rating Services, A.M. Best, Moody's, or a combination of the three. Excess of loss reinsurance We have XOL Transactions with a panel of unaffiliated reinsurers executed through the traditional reinsurance market (“Traditional XOL Transactions”) and with unaffiliated special purpose insurers (“Home Re Transactions”). We have entered into Traditional XOL Transactions with panels of third-party reinsurers. For the covered policies, we retain the first layer of the aggregate losses paid, and the reinsurers will then provide second layer coverage up to the outstanding reinsurance coverage amount. We retain losses paid in excess of the outstanding reinsurance coverage amount. The reinsurance coverage is subject to adjustment based on the risk characteristics of the covered loans until the initial excess of loss reinsurance coverage layer has been finalized. We can elect to terminate our Traditional XOL Transactions under specified scenarios without penalty upon prior written notice, including if we will receive less than the full credit amount under the PMIERs, full financial statement credit or full credit under applicable regulatory capital requirements for the risk ceded in any required calculation period. The reinsurance premiums ceded to the Traditional XOL Transactions are based off the remaining reinsurance coverage levels. The reinsured coverage levels are secured by funds on deposit from reinsurers (which does not include letters of credit), the minimum amount of which is based on the greater of 1) a reinsurer's funding requirements under PMIERs or 2) ceded reserves and unpaid losses. Each of the reinsurers under our Traditional XOL Transactions has an insurer financial strength rating of A- or better (or a comparable rating) by Standard and Poor’s Rating Services, A.M. Best, Moody’s, or a combination of the three. The Home Re Transactions are executed with unaffiliated special purpose insurers (“Home Re Entities”). For the reinsurance coverage periods, we retain the first layer of the respective aggregate losses paid, and a Home Re Entity will then provide second layer coverage up to the outstanding reinsurance coverage amount. We retain losses paid in excess of the outstanding reinsurance coverage amount. Subject to certain conditions, the reinsurance coverage decreases as the underlying covered mortgages amortize or are repaid, or mortgage insurance losses are paid. The Home Re Entities financed the collateral for the coverages by issuing mortgage insurance-linked notes (“ILNs”) to unaffiliated investors in an aggregate amount equal to the initial reinsurance coverage amounts. Each ILN is non-recourse to any assets of MGIC or affiliates. The proceeds of the ILNs, which were deposited into reinsurance trusts for the benefit of MGIC, will be the source of reinsurance claim payments to MGIC and principal repayments on the ILNs. Payment of principal on the related insurance-linked notes will be suspended and the reinsurance coverage available to MGIC under the transactions will not be reduced by such principal payments until a target level of credit enhancement is obtained or if certain thresholds or “Trigger Events” are reached, as defined in the related insurance-linked notes transaction agreement. As of September 30, 2023, a "Trigger Event" has occurred on our Home Re 2019-1 ILN transaction because the reinsured principal balance of loans that were reported 60 or more days delinquent exceeded a percentage of the total reinsured principal balance of loans specified under each transaction. In October 2023, Home Re 2019-1 Ltd., Home Re 2021-1 Ltd., and Home Re 2021-2 Ltd conducted tender offers for certain tranches of the mortgage insurance-linked notes that supported the reinsurance agreements with MGIC. The tender offer resulted in the reduction in the insurance-linked notes of $187.1 million for the Home Re 2019-1 Ltd, $91.1 million for the Home Re 2021-1 Ltd., and $106.7 million for the Home Re 2021-2 Ltd. The reinsurance coverage corresponding to the tendered notes was terminated. MGIC will incur approximately $8 million of additional ceded premium in the fourth quarter associated with the cost of the tender premiums and associated expenses. Also in October, 2023, MGIC entered into a $330.2 million excess-of-loss reinsurance agreement (executed through an insurance linked note transaction) that covers policies with inforce dates from June 1, 2022 through August 31, 2023. Table 4.4a provides a summary of our XOL Transactions as of September 30, 2023. Excess of Loss Reinsurance Table 4.4a ($ in thousands) Issue Date Policy In force Dates Optional Call Date (1) Legal Maturity Initial First Layer Retention Initial Excess of Loss Reinsurance Coverage 2023 Traditional XOL (2) April 1, 2023 January 1, 2023 - December 29, 2023 January 1, 2031 10 years TBD TBD 2022 Traditional XOL April 1, 2022 January 1, 2022 - December 30, 2022 January 1, 2030 10 years $82,523 $142,642 Home Re 2022-1, Ltd. April 26, 2022 May 29, 2021 - December 31, 2021 April 25, 2028 12.5 years 325,589 473,575 Home Re 2021-2, Ltd. August 3, 2021 January 1, 2021 - May 28, 2021 July 25, 2028 12.5 years 190,159 398,429 Home Re 2021-1, Ltd. February 2, 2021 August 1, 2020 - December 31, 2020 January 25, 2028 12.5 years 211,159 398,848 Home Re 2020-1, Ltd. October 29, 2020 January 1, 2020 - July 31, 2020 October 25, 2027 10 years 275,283 412,917 Home Re 2019-1, Ltd. May 25, 2019 January 1, 2018 - March 31, 2019 May 25, 2026 10 years 185,730 315,739 Home Re 2018-1, Ltd. October 30, 2018 July 1, 2016 - December 31, 2017 October 25, 2025 10 years 168,691 318,636 (1) We have the right to terminate the Home Re Transactions under certain circumstances, including an optional call feature that provides us the right to terminate if the outstanding principal balance of the related insurance-linked notes falls below 10% of the initial principal balance of the related insurance-linked notes, and on any payment date on or after the respective Optional Call Date. We can elect early termination of the Traditional XOL Transactions beginning on this date, and quarterly thereafter. (2) The 2023 Traditional XOL Transaction provides up to $116 million of reinsurance coverage on eligible NIW in 2023. Table 4.4b provides a summary of the remaining first layer retention and remaining excess of loss reinsurance coverage on our XOL Transactions as of September 30, 2023 and December 31, 2022. Table 4.4b Remaining First Layer Retention Remaining Excess of Loss Reinsurance Coverage ($ in thousands) September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 2022 Traditional XOL $ 82,463 $ 82,517 $ 142,642 $ 142,642 Home Re 2022-1, Ltd. 325,104 325,576 445,461 473,575 Home Re 2021-2, Ltd. 189,610 190,097 281,919 352,084 Home Re 2021-1, Ltd. 210,858 211,102 209,311 277,053 Home Re 2020-1, Ltd. 274,968 275,051 53,023 113,247 Home Re 2019-1, Ltd. 182,791 183,540 208,146 208,146 Home Re 2018-1, Ltd. 164,385 164,849 84,819 140,993 The reinsurance premiums ceded to each Home Re Entity are composed of coverage, initial expense and supplemental premiums. The coverage premiums are generally calculated as the difference between the amount of interest payable by the Home Re Entity on the remaining reinsurance coverage levels, and the investment income collected on the collateral assets held in a reinsurance trust account used to collateralize the Home Re Entity’s reinsurance obligation to MGIC. The amount of monthly reinsurance coverage premium ceded on the Home Re Transactions will fluctuate due to changes in the reference rate and changes in money market rates that affect investment income collected on the assets in the reinsurance trust. The Home Re 2021-2 and Home Re 2022-1 Transactions reference SOFR. The remaining Home Re Transactions referenced one-month LIBOR, and transitioned to SOFR when the one-month LIBOR rate was no longer published. As a result, we concluded that each Home Re Transaction contains an embedded derivative that is accounted for separately as a freestanding derivative. The fair values of the derivatives at September 30, 2023 and December 31, 2022, were not material to our consolidated balance sheet and the changes in fair value during the three and nine months ended September 30, 2023 and September 30, 2022 were not material to our consolidated statements of operations. (See Note 7 - “Investments” and Note 8 - “Fair Value Measurements ”.) At the time the Home Re Transactions were entered into, we concluded that each Home Re Entity is a variable interest entity (“VIE”). A VIE is a legal entity that does not have sufficient equity at risk to finance its activities without additional subordinated financial support or is structured such that equity investors lack the ability to make sufficient decisions relating to the entity’s operations through voting rights or do not substantively participate in gains and losses of the entity. Given that MGIC (1) does not have the unilateral power to direct the activities that most significantly affect each Home Re Entity’s economic performance and (2) does not have the obligation to absorb losses or the right to receive benefits of each Home Re Entity that could be significant to the Home Re Entity, consolidation of the Home Re Entities is not required. We are required to disclose our maximum exposure to loss, which we consider to be an amount that we could be required to record in our statements of operations, as a result of our involvement with the VIEs under our Home Re Transactions. As of September 30, 2023, and December 31, 2022, we did not have material exposure to the VIEs as we have no investment in the VIEs and had no reinsurance claim payments due from the VIEs under our reinsurance transactions. We are unable to determine the timing or extent of claims from losses that are ceded under the reinsurance transactions. The VIE assets are deposited in reinsurance trusts for the benefit of MGIC that will be the source of reinsurance claim payments to MGIC. The purpose of the reinsurance trusts is to provide security to MGIC for the obligations of the VIEs under the reinsurance transactions. The trustee of the reinsurance trusts, a recognized provider of corporate trust services, has established segregated accounts within the reinsurance trusts for the benefit of MGIC, pursuant to the trust agreements. The trust agreements are governed by, and construed in accordance with, the laws of the State of New York. If the trustee of the reinsurance trusts failed to distribute claim payments to us as provided in the reinsurance trusts, we would incur a loss related to our losses ceded under the reinsurance transactions and deemed unrecoverable. We are also unable to determine the impact such possible failure by the trustee to perform pursuant to the reinsurance trust agreements may have on our consolidated financial statements. As a result, we are unable to quantify our maximum exposure to loss related to our involvement with the VIEs. MGIC has certain termination rights under the reinsurance transactions should its claims not be paid. We consider our exposure to loss from our reinsurance transactions with the VIEs to be remote. Table 4.5 presents the total assets of the Home Re Entities as of September 30, 2023 and December 31, 2022. Home Re total assets Table 4.5 (In thousands) Total VIE Assets Home Re Entity September 30, 2023 December 31, 2022 Home Re 2022-1 Ltd. $ 454,943 $ 473,575 Home Re 2021-2 Ltd. 282,328 357,340 Home Re 2021-1 Ltd. 209,384 285,039 Home Re 2020-1 Ltd. 58,371 119,159 Home Re 2019-1 Ltd. 208,146 208,146 Home Re 2018-1 Ltd. 89,405 146,822 The reinsurance trust agreements provide that the trust assets may generally only be invested in certain money market funds that (i) invest at least 99.5% of their total assets in cash or direct U.S. federal government obligations, such as U.S. Treasury bills, as well as other short-term securities backed by the full faith and credit of the U.S. federal government or issued by an agency of the U.S. federal government, (ii) have a principal stability fund rating of “AAAm” by S&P or a money market fund rating of “Aaamf” by Moody’s as of the Closing Date and thereafter maintain any rating with either S&P or Moody’s, and (iii) are permitted investments under the applicable credit for reinsurance laws and applicable PMIERs credit for reinsurance requirements. The total calculated PMIERs credit for risk ceded under our XOL Transactions are generally based on the PMIERs requirement of the covered policies and the attachment and detachment points of the coverage, all of which fluctuate over time. (See Note 1 - “Nature of Business and Basis of Presentation” .)

Litigation and Contingencies

Litigation and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Litigation and Contingencies	Litigation and Contingencies Before paying an insurance claim, generally we review the loan and servicing files to determine the appropriateness of the claim amount. When reviewing the files, we may determine that we have the right to rescind coverage or deny a claim on the loan (both referred to herein as “rescissions”). In addition, our insurance policies generally provide that we can reduce a claim if the servicer did not comply with its obligations under our insurance policy (such reduction referred to as a “curtailment”). When the insured disputes our right to rescind coverage or curtail claims, we generally engage in discussions in an attempt to settle the dispute. If we are unable to reach a settlement, the outcome of a dispute ultimately may be determined by legal proceedings. Under ASC 450-20, until a loss associated with settlement discussions or legal proceedings becomes probable and can be reasonably estimated, we do not accrue an estimated loss. When we determine that a loss is probable and can be reasonably estimated, we record our best estimate of our probable loss. In those cases, until settlement negotiations or legal proceedings are concluded (including the receipt of any necessary GSE approvals), it is possible that we will record an additional loss. From time to time, we are involved in disputes and 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 disputes and legal proceedings will not have a material adverse effect on our financial position or results of operations.

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2023
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 shares of common stock outstanding. For purposes of calculating basic EPS, vested restricted stock and restricted stock units (“RSUs”) are considered outstanding. Diluted EPS includes the components of basic EPS and also gives effect to dilutive common stock equivalents. The determination of whether components are dilutive is calculated independently for each period. We calculate diluted EPS using the treasury stock method and if-converted method. Under the treasury stock method, diluted EPS reflects the potential dilution that could occur if unvested RSUs result in the issuance of common stock. Under the if-converted method, diluted EPS reflects the potential dilution that could occur if our 9% Debentures result in the issuance of common stock. The determination of potentially issuable shares does not consider the satisfaction of the conversion requirements and the shares are included in the determination of diluted EPS as of the beginning of the period, if dilutive. In the third quarter of 2023, under the terms of our 9% Debentures, we exercised our option to redeem the outstanding principal. (See Note 3 - “ Debt ” .) Table 6.1 reconciles the numerators and denominators used to calculate basic and diluted EPS. Earnings per share Table 6.1 Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2023 2022 2023 2022 Basic earnings per share: Net income $ 182,844 $ 249,625 $ 528,445 $ 673,906 Weighted average common shares outstanding - basic 281,757 302,622 286,184 309,097 Basic earnings per share $ 0.65 $ 0.82 $ 1.85 $ 2.18 Diluted earnings per share: Net income $ 182,844 $ 249,625 $ 528,445 $ 673,906 Interest expense, net of tax (1): 9% Debentures 276 620 1,025 2,851 Diluted income available to common shareholders $ 183,120 $ 250,245 $ 529,470 $ 676,757 Weighted average common shares outstanding - basic 281,757 302,622 286,184 309,097 Effect of dilutive securities: Unvested RSUs 2,624 1,902 2,239 1,848 9% Debentures 1,219 2,670 1,501 4,084 Weighted average common shares outstanding - diluted 285,600 307,194 289,924 315,029 Diluted earnings per share $ 0.64 $ 0.81 $ 1.83 $ 2.15 (1) Interest expense has been tax effected at a rate of 21%.

Investments

Investments	9 Months Ended
	Sep. 30, 2023
Investments [Abstract]
Investments	Investments Fixed income securities Our fixed income securities classified as available-for-sale at September 30, 2023 and December 31, 2022 are shown in tables 7.1a and 7.1b below. Details of fixed income securities by category as of September 30, 2023 Table 7.1a (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 220,592 $ 7 $ (9,765) $ 210,834 Obligations of U.S. states and political subdivisions 2,178,573 1,234 (274,157) 1,905,650 Corporate debt securities 2,564,817 498 (200,650) 2,364,665 ABS 172,262 9 (5,051) 167,220 RMBS 307,402 7 (34,727) 272,682 CMBS 297,091 65 (22,836) 274,320 CLOs 333,974 9 (2,256) 331,727 Foreign government debt 4,486 — (859) 3,627 Commercial paper 50,812 — — 50,812 Total fixed income securities (1) $ 6,130,009 $ 1,829 $ (550,301) $ 5,581,537 Details of fixed income securities by category as of December 31, 2022 Table 7.1b (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 145,581 $ 2 $ (9,683) $ 135,900 Obligations of U.S. states and political subdivisions 2,400,261 4,866 (256,073) 2,149,054 Corporate debt securities 2,416,475 1,043 (196,377) 2,221,141 ABS 126,723 5 (6,041) 120,687 RMBS 223,743 10 (25,744) 198,009 CMBS 257,785 22 (20,591) 237,216 CLOs 337,656 5 (7,829) 329,832 Foreign government debt 4,486 — (699) 3,787 Commercial paper 14,075 — (3) 14,072 Total fixed income securities (1) $ 5,926,785 $ 5,953 $ (523,040) $ 5,409,698 (1) Includes Short-Term Fixed Income Securities of $177.4 million and $67.0 million at September 30, 2023 and December 31, 2022, respectively. We had $11.5 million and $11.8 million of investments at fair value on deposit with various states as of September 30, 2023 and December 31, 2022, respectively, due to regulatory requirements of those state insurance departments. In connection with our insurance and reinsurance activities within MAC and MIC, insurance subsidiaries of MGIC, we are required to maintain assets in trusts for the benefit of contractual counterparties, which had investments at fair value of $143.8 million and $128.4 million at September 30, 2023 and December 31, 2022, respectively. The amortized cost and fair values of fixed income securities at September 30, 2023, by contractual maturity, are shown in table 7.2 below. Actual 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 mortgage and asset-backed securities provide for periodic payments throughout their lives, they are listed in separate categories. Fixed income securities maturity schedule Table 7.2 September 30, 2023 (In thousands) Amortized cost Fair Value Due in one year or less $ 667,446 $ 659,512 Due after one year through five years 1,543,417 1,458,444 Due after five years through ten years 1,805,365 1,617,227 Due after ten years 1,003,052 800,405 5,019,280 4,535,588 ABS 172,262 167,220 RMBS 307,402 272,682 CMBS 297,091 274,320 CLOs 333,974 331,727 Total $ 6,130,009 $ 5,581,537 Equity securities The cost and fair value of investments in equity securities at September 30, 2023 and December 31, 2022 are shown in tables 7.3a and 7.3b below. Details of equity security investments as of September 30, 2023 Table 7.3a (In thousands) Cost Gross Gains Gross Losses Fair Value Equity securities $ 15,998 $ — $ (2,049) $ 13,949 Details of equity security investments as of December 31, 2022 Table 7.3b (In thousands) Cost Gross Gains Gross Losses Fair Value Equity securities $ 15,924 $ — $ (1,784) $ 14,140 Net gains (losses) on investments and other financial instruments The net gains (losses) on investments and other financial instruments and the proceeds from the sale of fixed income securities classified as available-for-sale and equity securities are shown in table 7.4 below. Details of net gains (losses) on investments and other financial instruments Table 7.4 Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2023 2022 2023 2022 Fixed income securities Gains on sales 2,581 1,667 2,747 6,788 Losses on sales (2,814) (7,040) (13,362) (12,790) Impairments — (1,415) — (1,415) Equity securities gains (losses) Market adjustment (462) (617) (266) (2,351) Change in embedded derivative on Home Re Transactions (7) 4,199 (2,486) 983 Other Gains (losses) on sales (4) (66) (4) (18) Market adjustment 11 14 (9) 27 Net gains (losses) on investments and other financial instruments (695) (3,258) (13,380) (8,776) Proceeds from sales of fixed income securities 24,434 125,186 293,392 388,740 Other invested assets Our other invested assets balance includes an investment in FHLB stock that is carried at cost, which due to its nature approximates fair value. Ownership of FHLB stock provides access to a secured lending facility, subject to certain conditions, which includes requirements to post collateral and to maintain a minimum investment in FHLB stock. Unrealized investment losses Tables 7.5a and 7.5b below summarize, for all available-for-sale investments in an unrealized loss position at September 30, 2023 and December 31, 2022, the aggregate fair value and gross unrealized loss by the length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in tables 7.5a and 7.5b are estimated using the process described in Note 8 - “Fair Value Measurements” to these consolidated financial statements and in Note 3 - “Significant Accounting Policies” to the consolidated financial statements in our 2022 Annual Report on Form 10-K. Unrealized loss aging for securities by type and length of time as of September 30, 2023 Table 7.5a 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 $ 64,850 $ (538) $ 111,833 $ (9,227) $ 176,683 $ (9,765) Obligations of U.S. states and political subdivisions 674,000 (14,743) 1,226,433 (259,414) 1,900,433 (274,157) Corporate debt securities 600,174 (12,938) 1,745,339 (187,712) 2,345,513 (200,650) ABS 74,002 (950) 92,013 (4,101) 166,015 (5,051) RMBS 116,145 (6,082) 172,590 (28,645) 288,735 (34,727) CMBS 33,176 (2,433) 241,908 (20,403) 275,084 (22,836) CLOs — — 320,534 (2,256) 320,534 (2,256) Foreign government debt — — 3,627 (859) 3,627 (859) Total $ 1,562,347 $ (37,684) $ 3,914,277 $ (512,617) $ 5,476,624 $ (550,301) Unrealized loss aging for securities by type and length of time as of December 31, 2022 Table 7.5b 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 $ 67,531 $ (3,583) $ 76,246 $ (6,100) $ 143,777 $ (9,683) Obligations of U.S. states and political subdivisions 1,344,272 (157,903) 360,956 (98,170) 1,705,228 (256,073) Corporate debt securities 1,488,255 (109,976) 758,732 (86,401) 2,246,987 (196,377) ABS 53,201 (1,008) 67,073 (5,033) 120,274 (6,041) RMBS 77,563 (8,572) 136,179 (17,172) 213,742 (25,744) CMBS 166,973 (12,951) 70,792 (7,640) 237,765 (20,591) CLOs 213,461 (4,644) 114,459 (3,185) 327,920 (7,829) Foreign government debt — — 3,787 (699) 3,787 (699) Commercial paper — — 3,816 (3) 3,816 (3) Total $ 3,411,256 $ (298,637) $ 1,592,040 $ (224,403) $ 5,003,296 $ (523,040) There were 1,315 and 1,226 securities in an unrealized loss position at September 30, 2023 and December 31, 2022, respectively. Based on current facts and circumstances, we believe the unrealized losses as of September 30, 2023 presented in table 7.5a above are not indicative of the ultimate collectability of the current amortized cost of the securities. The unrealized losses in all categories of our investments at September 30, 2023 were primarily caused by an increase in prevailing interest rates. We also rely upon estimates of several credit and non-credit factors in our review and evaluation of individual investments to determine whether a credit impairment exists. All of the securities in an unrealized loss position are current with respect to their interest obligations.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Recurring fair value measurements The following describes the valuation methodologies generally used by the independent pricing sources, or by us, to measure financial instruments at fair value, including the general classification of such financial instruments pursuant to the valuation hierarchy. • Fixed income securities: U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies: Securities with valuations derived from quoted prices for identical instruments in active markets that we can access are categorized in Level 1 of the fair value hierarchy. Securities valued by surveying the dealer community, obtaining relevant trade data, benchmark quotes and spreads and incorporating this information in the valuation process are categorized as Level 2 of the fair value hierarchy. Corporate Debt Securities are valued by surveying the dealer community, obtaining relevant trade data, benchmark quotes and spreads and incorporating this information into the valuation process. These securities are generally categorized in Level 2 of the fair value hierarchy. Obligations of U.S. States & Political Subdivisions are valued by tracking, capturing, and analyzing quotes for active issues and trades reported via the Municipal Securities Rulemaking Board records. Daily briefings and reviews of current economic conditions, trading levels, spread relationships, and the slope of the yield curve provide further data for evaluation. These securities are generally categorized in Level 2 of the fair value hierarchy. Residential Mortgage-Backed Securities ("RMBS") are valued by monitoring interest rate movements, and other pertinent data daily. Incoming market data is enriched to derive spread, yield and/or price data as appropriate, enabling known data points to be extrapolated for valuation application across a range of related securities. These securities are generally categorized in Level 2 of the fair value hierarchy. Commercial Mortgage-Backed Securities ("CMBS") are valued using techniques that reflect market participants’ assumptions and maximize the use of relevant observable inputs including quoted prices for similar assets, benchmark yield curves and market corroborated inputs. Evaluation uses regular reviews of the inputs for securities covered, including executed trades, broker quotes, credit information, collateral attributes and/or cash flow waterfall as applicable. These securities are generally categorized in Level 2 of the fair value hierarchy. Asset-Backed Securities ("ABS") are valued using spreads and other information solicited from market buy-and-sell-side sources, including primary and secondary dealers, portfolio managers, and research analysts. Cash flows are generated for each tranche, benchmark yields are determined, and deal collateral performance and tranche level attributes including trade activity, bids, and offers are applied, resulting in tranche specific prices. These securities are generally categorized in Level 2 of the fair value hierarchy. Collateralized loan obligations ("CLOs") are valued by evaluating manager rating, seniority in the capital structure, assumptions about prepayment, default and recovery and their impact on cash flow generation. Loan level net asset values are determined and aggregated for tranches and as a final step prices are checked against available recent trade activity. These securities are generally categorized in Level 2 of the fair value hierarchy. Foreign government debt is valued by surveying the dealer community, obtaining relevant trade data, benchmark quotes and spreads and incorporating this information into the valuation process. These securities are generally categorized in Level 2 of the fair value hierarchy. Commercial Paper, which has an original maturity greater than 90 days , is valued using market data for comparable instruments of similar maturity and average yields. These securities are generally categorized in Level 2 of the fair value hierarchy. • Equity securities: Consist of actively traded, exchange-listed equity securities, including exchange traded funds (“ETFs”) and Bond Mutual Funds, with valuations derived from quoted prices for identical assets in active markets that we can access. These securities are valued in Level 1 of the fair value hierarchy. • Cash Equivalents: Consists of money market funds and treasury bills with valuations derived from quoted prices for identical assets in active markets that we can access. These securities are valued in level 1 of the fair value hierarchy. Instruments in this category valued using market data for comparable instruments are classified as level 2 in the fair value hierarchy. Assets measured at fair value, by hierarchy level, as of September 30, 2023 and December 31, 2022 are shown in tables 8.1a and 8.1b below. The fair value of the assets is estimated using the process described above, and more fully in Note 3 - “Significant Accounting Policies” to the consolidated financial statements in our 2022 Annual Report on Form 10-K. Assets carried at fair value by hierarchy level as of September 30, 2023 Table 8.1a (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 210,834 $ 140,891 $ 69,943 Obligations of U.S. states and political subdivisions 1,905,650 — 1,905,650 Corporate debt securities 2,364,665 — 2,364,665 ABS 167,220 — 167,220 RMBS 272,682 — 272,682 CMBS 274,320 — 274,320 CLOs 331,727 — 331,727 Foreign government debt 3,627 — 3,627 Commercial paper 50,812 — 50,812 Total fixed income securities 5,581,537 140,891 5,440,646 Equity securities 13,949 13,949 — Cash equivalents 271,924 (1) 255,772 16,152 Total $ 5,867,410 $ 410,612 $ 5,456,798 Assets carried at fair value by hierarchy level as of December 31, 2022 Table 8.1b (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 135,900 $ 116,897 $ 19,003 Obligations of U.S. states and political subdivisions 2,149,054 — 2,149,054 Corporate debt securities 2,221,141 — 2,221,141 ABS 120,687 — 120,687 RMBS 198,009 — 198,009 CMBS 237,216 — 237,216 CLOs 329,832 — 329,832 Foreign government debt 3,787 — 3,787 Commercial paper 14,072 — 14,072 Total fixed income securities 5,409,698 116,897 5,292,801 Equity securities 14,140 14,140 — Cash equivalents 328,756 (1) 324,129 4,627 Total $ 5,752,594 $ 455,166 $ 5,297,428 (1) Includes restricted cash equivalents Certain financial instruments, including insurance contracts, are excluded from these fair value disclosure requirements. The carrying values of cash (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.” In addition to the assets carried at fair value discussed above, we have embedded derivatives carried at fair value related to our Home Re Transactions that are classified as “Other liabilities” or “Other assets” in our consolidated balance sheets. The estimated fair value related to our embedded derivatives reflects the present value impact of the variation in investment income on the assets held by the reinsurance trusts and the contractual reference rate on the Home Re Transactions used to calculate the reinsurance premiums we estimate we will pay over the estimated remaining life. These liabilities or assets are categorized in Level 3 of the fair value hierarchy. At September 30, 2023 and December 31, 2022, the fair value of the embedded derivatives was a liability of less than $0.1 million and an asset of $2.5 million, respectively. (See Note 4 - "Reinsurance" for more information about our reinsurance programs.) Real estate acquired through claim settlement is carried at fair values and is reported in “Other assets” on the consolidated balance sheet. These assets are categorized as Level 3 of the fair value hierarchy. For the nine months ended September 30, 2023, and 2022, purchases of real estate acquired were $0.1 million and $2.9 million, respectively. For the nine months ended September 30, 2023, and 2022, sales of real estate acquired were $1.6 million and $3.2 million, respectively. Financial assets and liabilities not measured at fair value Other invested assets include an investment in FHLB stock that is carried at cost, which due to restrictions that require it to be redeemed or sold only to the security issuer at par value, approximates fair value. The fair value of other invested assets is categorized as Level 2. Financial liabilities include our outstanding debt obligations. The fair values of our 5.25% Notes and 9% Debentures were based on observable market prices. In all cases the fair values of the financial liabilities below are categorized as level 2. Table 8.2 presents the carrying value and fair value of our financial assets and liabilities disclosed, but not carried, at fair value at September 30, 2023 and December 31, 2022. Financial assets and liabilities not measured at fair value Table 8.2 September 30, 2023 December 31, 2022 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Financial assets Other invested assets $ 850 $ 850 $ 850 $ 850 Financial liabilities 5.25% Senior Notes 642,828 605,976 641,724 600,938 9% Convertible Junior Subordinated Debentures — — 21,086 28,085 Total financial liabilities $ 642,828 $ 605,976 $ 662,810 $ 629,023

Other Comprehensive Income

Other Comprehensive Income	9 Months Ended
	Sep. 30, 2023
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other Comprehensive Income	Other Comprehensive Income The pretax and related income tax benefit (expense) components of our other comprehensive income (loss) for the three and nine months ended September 30, 2023 and 2022 are included in table 9.1 below. Components of other comprehensive income (loss) Table 9.1 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2023 2022 2023 2022 Net unrealized investment (losses) gains arising during the period $ (95,216) $ (194,449) $ (31,387) $ (759,409) Total income tax benefit (expense) 19,995 40,834 6,591 159,476 Net of taxes (75,221) (153,615) (24,796) (599,933) Net changes in benefit plan assets and obligations 4,067 (20,471) 11,914 (19,353) Total income tax benefit (expense) (854) 4,299 (2,502) 4,064 Net of taxes 3,213 (16,172) 9,412 (15,289) Total other comprehensive income (loss) $ (91,149) (214,920) (19,473) (778,762) Total income tax benefit (expense) 19,141 45,133 4,089 163,540 Total other comprehensive income (loss), net of tax $ (72,008) $ (169,787) $ (15,384) $ (615,222) The pretax and related income tax benefit (expense) components of the amounts reclassified from our accumulated other comprehensive income (loss) (“AOCI”) to our consolidated statements of operations for the three and nine months ended September 30, 2023 and 2022 are included in table 9.2 below. Reclassifications from AOCI Table 9.2 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2023 2022 2023 2022 Reclassification adjustment for net realized (losses) gains (1) $ (3,085) $ (6,681) $ (13,020) $ (4,273) Income tax benefit (expense) 648 1,403 2,734 897 Net of taxes (2,437) (5,278) (10,286) (3,376) Reclassification adjustment related to benefit plan assets and obligations (2) (2,376) (6,228) (12,379) (7,346) Income tax benefit (expense) 499 1,308 2,600 1,543 Net of taxes (1,877) (4,920) (9,779) (5,803) Total reclassifications (5,461) (12,909) (25,399) (11,619) Income tax benefit (expense) 1,147 2,711 5,334 2,440 Total reclassifications, net of tax $ (4,314) $ (10,198) $ (20,065) $ (9,179) (1) Increases (decreases) Net realized investment gains (losses) on the consolidated statements of operations. (2) Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations. A rollforward of AOCI for the nine months ended September 30, 2023, including amounts reclassified from AOCI, are included in table 9.3 below. Rollforward of AOCI Table 9.3 Nine Months Ended September 30, 2023 (In thousands) Net unrealized gains and (losses) on available-for-sale securities Net benefit plan assets and (obligations) recognized in shareholders' equity Total accumulated other comprehensive income (loss) Balance at December 31, 2022, net of tax $ (408,496) $ (73,015) $ (481,511) Other comprehensive income (loss) before reclassifications (35,082) (367) (35,449) Less: Amounts reclassified from AOCI (10,286) (9,779) (20,065) Balance, September 30, 2023, net of tax $ (433,292) $ (63,603) $ (496,895)

Benefit Plans

Benefit Plans	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans Tables 10.1 and 10.2 provide the components of net periodic benefit cost for our pension, supplemental executive retirement and other postretirement benefit plans for the three and nine months ended September 30, 2023 and 2022. Components of net periodic benefit cost Table 10.1 Three Months Ended September 30, Pension and Supplemental Executive Retirement Plans Other Postretirement Benefit Plans (In thousands) 2023 2022 2023 2022 Company service cost $ — $ 1,813 $ 374 $ 327 Interest cost 3,297 2,863 409 173 Expected return on plan assets (3,426) (4,907) (2,059) (2,625) Amortization of: Net actuarial losses (gains) 529 1,266 (38) (776) Prior service cost (credit) 87 (57) 465 123 Cost of settlements and curtailments 334 5,671 — — Net periodic benefit cost (benefit) $ 821 $ 6,649 $ (849) $ (2,778) Components of net periodic benefit cost Table 10.2 Nine Months Ended September 30, Pension and Supplemental Executive Retirement Plans Other Postretirement Benefit Plans (In thousands) 2023 2022 2023 2022 Company service cost $ — $ 5,439 $ 1,122 $ 981 Interest cost 10,278 8,588 1,225 521 Expected return on plan assets (10,432) (14,723) (6,176) (7,876) Amortization of: Net actuarial losses (gains) 1,656 3,798 (113) (2,328) Prior service cost (credit) 259 (163) 1,396 367 Cost of settlements and curtailments 9,181 5,671 — — Net periodic benefit cost (benefit) $ 10,942 $ 8,610 $ (2,546) $ (8,335)

Loss Reserves

Loss Reserves	3 Months Ended
	Sep. 30, 2023
Insurance Loss Reserves [Abstract]
Loss Reserves	Loss Reserves We establish case reserves and LAE reserves on delinquent loans that were reported to us as two or more payments past due and have not become current or resulted in a claim payment. Such loans are referred to as being in our delinquency inventory. Case reserves are established by estimating the number of loans in our delinquency inventory that will result in a claim payment, which is referred to as the claim rate, and further estimating the amount of the claim payment, which is referred to as claim severity. IBNR reserves are established for estimated losses from delinquencies we estimate have occurred prior to the close of an accounting period but have not yet been reported to us. IBNR reserves are also established using estimated claim rates and claim severities. Estimation of losses is inherently judgmental. Even in a stable environment, changes to our estimates could result in a material impact to our consolidated results of operations and financial position. The conditions that affect the claim rate and claim severity include the current and future state of the domestic economy, including unemployment and the current and future strength of local housing markets; exposure on insured loans; the amount of time between delinquency and claim filing (all else being equal, the longer the period between delinquency and claim filing, the greater the severity); and curtailments and rescissions. The actual amount of the claim payments may be substantially different than our loss reserve estimates. Our estimates could be adversely affected by several factors, including a deterioration of regional or national economic conditions, including unemployment, leading to a reduction in borrowers’ income and thus their ability to make mortgage payments, the impact of past and future government initiatives and actions taken by the GSEs (including mortgage forbearance programs and foreclosure moratoriums), 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. Loss reserves in future periods will also be dependent on the number of loans reported to us as delinquent. Changes to our estimates could result in a material impact to our consolidated results of operations and financial position, even in a stable economic environment. Given the uncertainty of the macroeconomic environment, including the effectiveness of loss mitigation efforts, change in home prices, and changes in unemployment, our loss reserve estimates may continue to be impacted. In considering the potential sensitivity of the factors underlying our estimate of loss reserves, it is possible that even a relatively small change in our estimated claim rate or claim severity could have a material impact on loss reserves and, correspondingly, on our consolidated results of operations even in a stable economic environment. For example, as of September 30, 2023, assuming all other factors remain constant, a $1,000 increase/decrease in the average severity reserve factor would change the loss reserve amount by approximately +/- $9 million. A one percentage point increase/decrease in the average claim rate reserve factor would change the loss reserve amount by approximately +/- $15 million. The “Losses incurred” section of table 11.1 below shows losses incurred on delinquencies that occurred in the current year and in prior years. The amount of losses incurred relating to delinquencies that occurred in the current year represents the estimated amount to be ultimately paid on such delinquencies. The amount of losses incurred relating to delinquencies that occurred in prior years represents the difference between the actual claim rate and claim severity associated with those delinquencies resolved in the current year compared to the estimated claim rate and claim severity at the prior year-end, as well as a re-estimation of amounts to be ultimately paid on delinquencies continuing from the end of the prior year. This re-estimation of the claim rate and claim severity is the result of our review of current trends in the delinquency inventory, such as percentages of delinquencies that have resulted in a claim, the amount of the claims relative to the average loan exposure, changes in the relative level of delinquencies by geography and changes in average loan exposure. Losses incurred on delinquencies that occurred in the current year increased for the nine months ended September 30, 2023, compared to the same period last year. The increase is primarily due to an increase in estimated severity on current year delinquencies and an increase in new delinquencies reported. For the nine months ended September 30, 2023 and September 30, 2022 we experienced favorable loss development of $148.9 million and $327.5 million, respectively, on previously received delinquencies. The favorable development for both periods primarily resulted from a decrease in the expected claim rate on previously received delinquencies. Home price appreciation experienced in recent years has allowed some borrowers to cure their delinquencies through the sale of their property. The “Losses paid” section of table 11.1 below shows the amount of losses paid on delinquencies that occurred in the current year and losses paid on delinquencies that occurred in prior years. Table 11.1 provides a reconciliation of beginning and ending loss reserves as of and for the nine months ended September 30, 2023 and 2022. Development of reserves for losses and loss adjustment expenses Table 11.1 Nine Months Ended September 30, (In thousands) 2023 2022 Reserve at beginning of period $ 557,988 $ 883,522 Less reinsurance recoverable 28,240 66,905 Net reserve at beginning of period 529,748 816,617 Losses incurred: Losses and LAE incurred in respect of delinquency notices received in: Current year 137,626 104,086 Prior years (1) (148,948) (327,512) Total losses incurred (11,322) (223,426) Losses paid: Losses and LAE paid in respect of delinquency notices received in: Current year 153 116 Prior years 33,679 36,089 Total losses paid 33,832 36,205 Net reserve at end of period 484,594 556,986 Plus reinsurance recoverable 40,934 46,384 Reserve at end of period $ 525,528 $ 603,370 (1) A positive number for prior year loss reserve development indicates a deficiency of prior year reserves. A negative number for prior year loss reserve development indicates a redundancy of prior year loss reserves. See the following table for more information about prior year loss reserve development. The prior year loss reserve development for the nine months ended September 30, 2023 and 2022 is shown in table 11.2 below. Reserve development on previously received delinquencies Table 11.2 Nine Months Ended September 30, (In thousands) 2023 2022 Increase (decrease) in estimated claim rate on primary defaults $ (142,764) $ (324,556) Change in estimates related to severity on primary defaults, pool reserves, LAE reserves, reinsurance, and other (6,184) (2,956) Total prior year loss development (1) $ (148,948) $ (327,512) (1) A positive number for prior year loss reserve development indicates a deficiency of prior year loss reserves. A negative number for prior year loss reserve development indicates a redundancy of prior year loss reserves. Delinquency inventory A rollforward of our primary delinquency inventory for the three and nine months ended September 30, 2023 and 2022 appears in table 11.3 below. The information concerning new notices and cures is compiled from monthly reports received from loan servicers. The level of new notice and cure activity reported in a particular month can be influenced by, among other things, the date on which a servicer generates its report, the number of business days in a month and transfers of servicing between loan servicers. Delinquency inventory rollforward Table 11.3 Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Delinquency inventory at beginning of period 23,823 26,855 26,387 33,290 New notices 12,240 10,990 34,117 31,089 Cures (10,975) (11,494) (34,738) (37,371) Paid claims (359) (337) (1,018) (978) Rescissions and denials (9) (11) (28) (27) Other items removed from inventory — (125) — (125) Delinquency inventory at end of period 24,720 25,878 24,720 25,878 Table 11.4 below shows the number of consecutive months a borrower is delinquent. Historically as a delinquency ages it is more likely to result in a claim. Primary delinquency inventory - consecutive months delinquent Table 11.4 September 30, 2023 December 31, 2022 September 30, 2022 3 months or less 8,732 8,820 7,825 4-11 months 8,220 8,217 7,619 12 months or more (1) 7,768 9,350 10,434 Total 24,720 26,387 25,878 3 months or less 35 % 33 % 30 % 4-11 months 33 % 31 % 30 % 12 months or more 32 % 36 % 40 % Total 100 % 100 % 100 % Primary claims received inventory included in ending delinquent inventory 284 267 244 (1) Approximately 39%, 36%, and 33% of the primary delinquency inventory delinquent for 12 consecutive months or more has been delinquent for at least 36 consecutive months as of September 30, 2023, December 31, 2022, and September 30, 2022, respectively. Premium refunds Our estimate of premiums to be refunded on expected claim payments is accrued for separately in “Other Liabilities” on our consolidated balance sheets and approximated $19.6 million and $25.5 million at September 30, 2023 and December 31, 2022, respectively.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2023
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Share repurchase programs Repurchases of our common stock may be made from time to time on the open market (including through 10b5-1 plans) or through privately negotiated transactions. In the nine months ended September 30, 2023, we repurchased 14.7 million shares at an average cost of $14.83 per share, which included commissions. In 2022, we repurchased approximately 27.8 million shares of our common stock, at an average cost of $13.89 per share, which included commissions. At September 30, 2023, we had $396 million remaining under a $500 million share repurchase program approved by our Board of Directors in 2023 that expires on July 1, 2025. Through October 27, 2023, we repurchased an additional 2.2 million shares totaling $36.5 million under the remaining authorization. Cash dividends In the first and second quarters of 2023, we paid quarterly cash dividends of $0.10 per share which totaled $58.8 million. In August 2023, we paid quarterly cash dividends of $0.115 per share to shareholders which totaled $32.9 million. On October 26, 2023, the Board of Directors declared a quarterly cash dividend of to the holders of the company’s common stock of $0.115 per share to shareholders of record on November 9, 2023. 9% Debenture Conversion In the third quarter of 2023, we exercised our option to redeem the outstanding principal of $21.1 million on our 9% Debentures. Prior to the redemption date, substantially all holders elected to convert into shares of our common stock. We elected to pay cash in lieu of issuing shares. The conversion of our 9% Debentures resulted in a reduction in our shareholders’ equity of $5.3 million, net of tax. See Note 3 – “ Debt .”

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	Share-Based Compensation We have certain share-based compensation plans. Under the fair value method, compensation cost is measured at the grant date based on the fair value of the award and is recognized over the service period which generally corresponds to the vesting period. Awards under our plans generally vest over periods ranging from one Table 13.1 shows the number of restricted stock units (RSUs) granted to employees and non-employee directors and the weighted average fair value per share during the periods presented. Restricted stock unit grants Table 13.1 Nine months ended September 30, 2023 2022 RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs subject to performance conditions (1) 949 $ 14.17 848 $ 15.46 RSUs subject only to service conditions 354 14.17 319 15.45 Non-employee director RSUs 106 14.17 104 15.32 (1) Shares granted are subject to performance conditions under which the target number of shares granted may vest up to 200%.

Statutory Information

Statutory Information	3 Months Ended
	Sep. 30, 2023
Statutory Capital [Abstract]
Insurance Disclosure	Statutory Information Statutory Capital Requirements The insurance laws of 16 jurisdictions, including Wisconsin, our domiciliary state, require a mortgage insurer to maintain a minimum amount of statutory capital relative to the RIF (or a similar measure) in order for the mortgage insurer to continue to write new business. We refer to these requirements as the “State Capital Requirements” and, together with the GSE Financial Requirements, as 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”). MGIC’s “policyholder position” includes its net worth or surplus, and its contingency loss reserve. At September 30, 2023, MGIC’s risk-to-capital ratio was 9.6 to 1, below the maximum allowed by the jurisdictions with State Capital Requirements, and its policyholder position was $3.8 billion above the required MPP of $2.1 billion. The calculation of our risk-to-capital ratio and MPP reflect credit for the risk ceded under our reinsurance transactions. If MGIC is not allowed an agreed level of credit under either the State Capital Requirements or the financial requirements of the PMIERs, MGIC may terminate the reinsurance agreements without penalty. Dividend restrictions 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 two The OCI recognizes only statutory accounting principles prescribed, or practices permitted by the State of Wisconsin for determining and reporting the financial condition and results of operations of an insurance company. The OCI has adopted certain prescribed accounting practices that differ from those found in other states. Specifically, Wisconsin domiciled companies record changes in the contingency loss reserves through their income statement as a change in underwriting deduction. As a result, in periods in which MGIC is increasing contingency loss reserves, statutory net income is reduced. Statutory Financial Information The statutory net income, policyholders’ surplus, and contingency loss reserves of our insurance subsidiaries, including MGIC, are shown in table 14.1. Financial information of our insurance subsidiaries (including MGIC) Table 14.1 As of and for the Nine Months Ended September 30, (In thousands) 2023 2022 Statutory net income $ 207,996 $ 284,084 Statutory policyholders' surplus 859,083 1,231,992 Contingency loss reserves 5,071,276 4,533,371

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net income	$ 182,844	$ 249,625	$ 528,445	$ 673,906

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Prospective Accounting Standards	Accounting standards and laws and regulations effective in 2023, or early adopted, and relevant to our financial statements are described below: Reference Rate Reform: ASU 2022-06 In March 2020, the FASB issued ASU 2020-04 to provide temporary optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform. It provided optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. In December 2022, the FASB issued ASU 2022-06, extending the election and application from March 12, 2020 through December 31, 2024 (originally December 31, 2022). Future elections of this standard will ease, if warranted, the requirements for accounting for the future effects of reference rate reform. We have evaluated the impact the discontinuance of LIBOR will have on our consolidated financial statements and have determined it will not have a material impact. Inflation Reduction Act On August 16, 2022, the Inflation Reduction Act (the “IRA”) was enacted and signed into law in the United States. The IRA includes provisions for a 15% corporate minimum tax and a 1% excise tax on net stock repurchases. Both of these taxes are effective in 2023. We do not expect these tax provisions to have a material impact on our consolidated financial results, including our annual estimated effective tax rate. The amount of the excise tax on the repurchase of corporate stock was immaterial for the nine months ended September 30, 2023.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Long-term debt	The aggregate carrying values of our long-term debt obligations and their par values, if different, as of September 30, 2023 and December 31, 2022 are presented in table 3.1 below. Long-term debt obligations Table 3.1 (In thousands) September 30, 2023 December 31, 2022 5.25% Notes, due August 2028 (par value: $650 million) $ 642,828 $ 641,724 9% Debentures, due April 2063 — 21,086 Long-term debt, carrying value $ 642,828 $ 662,810

Reinsurance (Tables)

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2023
Reinsurance Disclosures [Abstract]
Effect of reinsurance transactions	The effect of all of our reinsurance transactions on our consolidated statement of operations is shown in table 4.1 below. Reinsurance Table 4.1 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2023 2022 2023 2022 Premiums earned: Direct $ 287,640 $ 289,072 $ 858,310 $ 864,191 Assumed 3,801 2,254 9,635 6,501 Ceded - quota share reinsurance (1) (32,693) (19,348) (90,012) (56,721) Ceded - excess-of-loss reinsurance (17,471) (19,867) (51,830) (50,923) Total ceded (50,164) (39,215) (141,842) (107,644) Net premiums earned $ 241,277 $ 252,111 $ 726,103 $ 763,048 Losses incurred: Direct $ 6,627 $ (112,435) $ 2,044 $ (242,861) Assumed 20 21 (7) (340) Ceded - quota share reinsurance (6,724) 7,360 (13,359) 19,775 Losses incurred, net $ (77) $ (105,054) $ (11,322) $ (223,426) Other Reinsurance Impacts: Profit commission on quota share reinsurance (1) $ 30,698 $ 47,255 $ 97,218 $ 135,049 Ceding commission on quota share reinsurance 12,678 13,321 37,446 38,355 (1) Ceded premiums earned are shown net of profit commission.
Schedule Of Quota Share Reinsurance Transactions	Table 4.2 below provides additional detail regarding our QSR Transactions. Quota Share Reinsurance Table 4.2 Quota Share Contract Covered Policy Years Quota Share % Annual Loss Ratio to Exhaust Profit Commission (1) Contractual Termination Date 2020 QSR 2020 12.5 % 62.0 % December 31, 2031 2020 QSR and 2021 QSR 2020 17.5 % 62.0 % December 31, 2032 2020 QSR and 2021 QSR 2021 17.5 % 61.9 % December 31, 2032 2021 QSR and 2022 QSR 2021 12.5 % 57.5 % December 31, 2032 2021 QSR and 2022 QSR 2022 15.0 % 57.5 % December 31, 2033 2022 QSR and 2023 QSR 2022 15.0 % 62.0 % December 31, 2033 2022 QSR and 2023 QSR 2023 15.0 % 62.0 % December 31, 2034 2023 QSR 2023 10.0 % 58.5 % December 31, 2034 Credit Union QSR 2020-2025 65.0 % 50.0 % December 31, 2039 (1) We will receive a profit commission provided the annual loss ratio on policies covered under the transaction remains below this ratio. Table 4.3 provides additional details regarding optional termination dates and optional reductions to our quota share percentage which can, in each case, be elected by us for a fee. Under the optional reduction to the quota share percentage, we may reduce our quota share percentage from the original percentage shown in table 4.2 to the percentage shown in table 4.3. Quota Share Reinsurance Table 4.3 Quota Share Contract Covered Policy Years Optional Termination Date (1) Optional Quota Share % Reduction Date (2) Optional Reduced Quota Share % 2020 QSR 2020 December 31, 2023 January 1, 2024 10.5% or 8% 2020 QSR and 2021 QSR 2020 December 31, 2023 January 1, 2024 14.5% or 12% 2020 QSR and 2021 QSR 2021 December 31, 2023 January 1, 2024 14.5% or 12% 2021 QSR and 2022 QSR 2021 December 31, 2023 January 1, 2024 10.5% or 8% 2021 QSR and 2022 QSR 2022 December 31, 2024 January 1, 2024 12.5% or 10% 2022 QSR and 2023 QSR 2022 December 31, 2024 January 1, 2024 12.5% or 10% 2022 QSR and 2023 QSR 2023 December 31, 2025 July 1, 2024 12.5% or 10% 2023 QSR 2023 December 31, 2025 July 1, 2024 8% or 7% (1) We can elect early termination of the QSR Transaction beginning on this date, and semi-annually thereafter.
Schedule of coverages and retention	Table 4.4a provides a summary of our XOL Transactions as of September 30, 2023. Excess of Loss Reinsurance Table 4.4a ($ in thousands) Issue Date Policy In force Dates Optional Call Date (1) Legal Maturity Initial First Layer Retention Initial Excess of Loss Reinsurance Coverage 2023 Traditional XOL (2) April 1, 2023 January 1, 2023 - December 29, 2023 January 1, 2031 10 years TBD TBD 2022 Traditional XOL April 1, 2022 January 1, 2022 - December 30, 2022 January 1, 2030 10 years $82,523 $142,642 Home Re 2022-1, Ltd. April 26, 2022 May 29, 2021 - December 31, 2021 April 25, 2028 12.5 years 325,589 473,575 Home Re 2021-2, Ltd. August 3, 2021 January 1, 2021 - May 28, 2021 July 25, 2028 12.5 years 190,159 398,429 Home Re 2021-1, Ltd. February 2, 2021 August 1, 2020 - December 31, 2020 January 25, 2028 12.5 years 211,159 398,848 Home Re 2020-1, Ltd. October 29, 2020 January 1, 2020 - July 31, 2020 October 25, 2027 10 years 275,283 412,917 Home Re 2019-1, Ltd. May 25, 2019 January 1, 2018 - March 31, 2019 May 25, 2026 10 years 185,730 315,739 Home Re 2018-1, Ltd. October 30, 2018 July 1, 2016 - December 31, 2017 October 25, 2025 10 years 168,691 318,636 (1) We have the right to terminate the Home Re Transactions under certain circumstances, including an optional call feature that provides us the right to terminate if the outstanding principal balance of the related insurance-linked notes falls below 10% of the initial principal balance of the related insurance-linked notes, and on any payment date on or after the respective Optional Call Date. We can elect early termination of the Traditional XOL Transactions beginning on this date, and quarterly thereafter. (2) The 2023 Traditional XOL Transaction provides up to $116 million of reinsurance coverage on eligible NIW in 2023. Table 4.4b provides a summary of the remaining first layer retention and remaining excess of loss reinsurance coverage on our XOL Transactions as of September 30, 2023 and December 31, 2022. Table 4.4b Remaining First Layer Retention Remaining Excess of Loss Reinsurance Coverage ($ in thousands) September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 2022 Traditional XOL $ 82,463 $ 82,517 $ 142,642 $ 142,642 Home Re 2022-1, Ltd. 325,104 325,576 445,461 473,575 Home Re 2021-2, Ltd. 189,610 190,097 281,919 352,084 Home Re 2021-1, Ltd. 210,858 211,102 209,311 277,053 Home Re 2020-1, Ltd. 274,968 275,051 53,023 113,247 Home Re 2019-1, Ltd. 182,791 183,540 208,146 208,146 Home Re 2018-1, Ltd. 164,385 164,849 84,819 140,993
Schedule of total assets of Home Re	Table 4.5 presents the total assets of the Home Re Entities as of September 30, 2023 and December 31, 2022. Home Re total assets Table 4.5 (In thousands) Total VIE Assets Home Re Entity September 30, 2023 December 31, 2022 Home Re 2022-1 Ltd. $ 454,943 $ 473,575 Home Re 2021-2 Ltd. 282,328 357,340 Home Re 2021-1 Ltd. 209,384 285,039 Home Re 2020-1 Ltd. 58,371 119,159 Home Re 2019-1 Ltd. 208,146 208,146 Home Re 2018-1 Ltd. 89,405 146,822

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Calculation of earnings (loss) per share	Table 6.1 reconciles the numerators and denominators used to calculate basic and diluted EPS. Earnings per share Table 6.1 Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2023 2022 2023 2022 Basic earnings per share: Net income $ 182,844 $ 249,625 $ 528,445 $ 673,906 Weighted average common shares outstanding - basic 281,757 302,622 286,184 309,097 Basic earnings per share $ 0.65 $ 0.82 $ 1.85 $ 2.18 Diluted earnings per share: Net income $ 182,844 $ 249,625 $ 528,445 $ 673,906 Interest expense, net of tax (1): 9% Debentures 276 620 1,025 2,851 Diluted income available to common shareholders $ 183,120 $ 250,245 $ 529,470 $ 676,757 Weighted average common shares outstanding - basic 281,757 302,622 286,184 309,097 Effect of dilutive securities: Unvested RSUs 2,624 1,902 2,239 1,848 9% Debentures 1,219 2,670 1,501 4,084 Weighted average common shares outstanding - diluted 285,600 307,194 289,924 315,029 Diluted earnings per share $ 0.64 $ 0.81 $ 1.83 $ 2.15 (1) Interest expense has been tax effected at a rate of 21%.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2023
Investments [Abstract]
Amortized cost, gross unrealized gains and losses and fair value of fixed income securities	Our fixed income securities classified as available-for-sale at September 30, 2023 and December 31, 2022 are shown in tables 7.1a and 7.1b below. Details of fixed income securities by category as of September 30, 2023 Table 7.1a (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 220,592 $ 7 $ (9,765) $ 210,834 Obligations of U.S. states and political subdivisions 2,178,573 1,234 (274,157) 1,905,650 Corporate debt securities 2,564,817 498 (200,650) 2,364,665 ABS 172,262 9 (5,051) 167,220 RMBS 307,402 7 (34,727) 272,682 CMBS 297,091 65 (22,836) 274,320 CLOs 333,974 9 (2,256) 331,727 Foreign government debt 4,486 — (859) 3,627 Commercial paper 50,812 — — 50,812 Total fixed income securities (1) $ 6,130,009 $ 1,829 $ (550,301) $ 5,581,537 Details of fixed income securities by category as of December 31, 2022 Table 7.1b (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 145,581 $ 2 $ (9,683) $ 135,900 Obligations of U.S. states and political subdivisions 2,400,261 4,866 (256,073) 2,149,054 Corporate debt securities 2,416,475 1,043 (196,377) 2,221,141 ABS 126,723 5 (6,041) 120,687 RMBS 223,743 10 (25,744) 198,009 CMBS 257,785 22 (20,591) 237,216 CLOs 337,656 5 (7,829) 329,832 Foreign government debt 4,486 — (699) 3,787 Commercial paper 14,075 — (3) 14,072 Total fixed income securities (1) $ 5,926,785 $ 5,953 $ (523,040) $ 5,409,698 (1) Includes Short-Term Fixed Income Securities of $177.4 million and $67.0 million at September 30, 2023 and December 31, 2022, respectively.
Amortized cost and fair values of fixed income securities by contractual maturity	The amortized cost and fair values of fixed income securities at September 30, 2023, by contractual maturity, are shown in table 7.2 below. Actual 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 mortgage and asset-backed securities provide for periodic payments throughout their lives, they are listed in separate categories. Fixed income securities maturity schedule Table 7.2 September 30, 2023 (In thousands) Amortized cost Fair Value Due in one year or less $ 667,446 $ 659,512 Due after one year through five years 1,543,417 1,458,444 Due after five years through ten years 1,805,365 1,617,227 Due after ten years 1,003,052 800,405 5,019,280 4,535,588 ABS 172,262 167,220 RMBS 307,402 272,682 CMBS 297,091 274,320 CLOs 333,974 331,727 Total $ 6,130,009 $ 5,581,537
Cost and fair value of investments in equity securities	The cost and fair value of investments in equity securities at September 30, 2023 and December 31, 2022 are shown in tables 7.3a and 7.3b below. Details of equity security investments as of September 30, 2023 Table 7.3a (In thousands) Cost Gross Gains Gross Losses Fair Value Equity securities $ 15,998 $ — $ (2,049) $ 13,949 Details of equity security investments as of December 31, 2022 Table 7.3b (In thousands) Cost Gross Gains Gross Losses Fair Value Equity securities $ 15,924 $ — $ (1,784) $ 14,140
Schedule of realized gains (losses) and proceeds from sale of securities	The net gains (losses) on investments and other financial instruments and the proceeds from the sale of fixed income securities classified as available-for-sale and equity securities are shown in table 7.4 below. Details of net gains (losses) on investments and other financial instruments Table 7.4 Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2023 2022 2023 2022 Fixed income securities Gains on sales 2,581 1,667 2,747 6,788 Losses on sales (2,814) (7,040) (13,362) (12,790) Impairments — (1,415) — (1,415) Equity securities gains (losses) Market adjustment (462) (617) (266) (2,351) Change in embedded derivative on Home Re Transactions (7) 4,199 (2,486) 983 Other Gains (losses) on sales (4) (66) (4) (18) Market adjustment 11 14 (9) 27 Net gains (losses) on investments and other financial instruments (695) (3,258) (13,380) (8,776) Proceeds from sales of fixed income securities 24,434 125,186 293,392 388,740
Aging of the fair values of securities in an unrealized loss position	Tables 7.5a and 7.5b below summarize, for all available-for-sale investments in an unrealized loss position at September 30, 2023 and December 31, 2022, the aggregate fair value and gross unrealized loss by the length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in tables 7.5a and 7.5b are estimated using the process described in Note 8 - “Fair Value Measurements” to these consolidated financial statements and in Note 3 - “Significant Accounting Policies” to the consolidated financial statements in our 2022 Annual Report on Form 10-K. Unrealized loss aging for securities by type and length of time as of September 30, 2023 Table 7.5a 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 $ 64,850 $ (538) $ 111,833 $ (9,227) $ 176,683 $ (9,765) Obligations of U.S. states and political subdivisions 674,000 (14,743) 1,226,433 (259,414) 1,900,433 (274,157) Corporate debt securities 600,174 (12,938) 1,745,339 (187,712) 2,345,513 (200,650) ABS 74,002 (950) 92,013 (4,101) 166,015 (5,051) RMBS 116,145 (6,082) 172,590 (28,645) 288,735 (34,727) CMBS 33,176 (2,433) 241,908 (20,403) 275,084 (22,836) CLOs — — 320,534 (2,256) 320,534 (2,256) Foreign government debt — — 3,627 (859) 3,627 (859) Total $ 1,562,347 $ (37,684) $ 3,914,277 $ (512,617) $ 5,476,624 $ (550,301) Unrealized loss aging for securities by type and length of time as of December 31, 2022 Table 7.5b 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 $ 67,531 $ (3,583) $ 76,246 $ (6,100) $ 143,777 $ (9,683) Obligations of U.S. states and political subdivisions 1,344,272 (157,903) 360,956 (98,170) 1,705,228 (256,073) Corporate debt securities 1,488,255 (109,976) 758,732 (86,401) 2,246,987 (196,377) ABS 53,201 (1,008) 67,073 (5,033) 120,274 (6,041) RMBS 77,563 (8,572) 136,179 (17,172) 213,742 (25,744) CMBS 166,973 (12,951) 70,792 (7,640) 237,765 (20,591) CLOs 213,461 (4,644) 114,459 (3,185) 327,920 (7,829) Foreign government debt — — 3,787 (699) 3,787 (699) Commercial paper — — 3,816 (3) 3,816 (3) Total $ 3,411,256 $ (298,637) $ 1,592,040 $ (224,403) $ 5,003,296 $ (523,040)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair value measurements for items measured at fair value	Assets measured at fair value, by hierarchy level, as of September 30, 2023 and December 31, 2022 are shown in tables 8.1a and 8.1b below. The fair value of the assets is estimated using the process described above, and more fully in Note 3 - “Significant Accounting Policies” to the consolidated financial statements in our 2022 Annual Report on Form 10-K. Assets carried at fair value by hierarchy level as of September 30, 2023 Table 8.1a (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 210,834 $ 140,891 $ 69,943 Obligations of U.S. states and political subdivisions 1,905,650 — 1,905,650 Corporate debt securities 2,364,665 — 2,364,665 ABS 167,220 — 167,220 RMBS 272,682 — 272,682 CMBS 274,320 — 274,320 CLOs 331,727 — 331,727 Foreign government debt 3,627 — 3,627 Commercial paper 50,812 — 50,812 Total fixed income securities 5,581,537 140,891 5,440,646 Equity securities 13,949 13,949 — Cash equivalents 271,924 (1) 255,772 16,152 Total $ 5,867,410 $ 410,612 $ 5,456,798 Assets carried at fair value by hierarchy level as of December 31, 2022 Table 8.1b (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 135,900 $ 116,897 $ 19,003 Obligations of U.S. states and political subdivisions 2,149,054 — 2,149,054 Corporate debt securities 2,221,141 — 2,221,141 ABS 120,687 — 120,687 RMBS 198,009 — 198,009 CMBS 237,216 — 237,216 CLOs 329,832 — 329,832 Foreign government debt 3,787 — 3,787 Commercial paper 14,072 — 14,072 Total fixed income securities 5,409,698 116,897 5,292,801 Equity securities 14,140 14,140 — Cash equivalents 328,756 (1) 324,129 4,627 Total $ 5,752,594 $ 455,166 $ 5,297,428 (1) Includes restricted cash equivalents
Carrying value and fair value of financial assets and liabilities	Table 8.2 presents the carrying value and fair value of our financial assets and liabilities disclosed, but not carried, at fair value at September 30, 2023 and December 31, 2022. Financial assets and liabilities not measured at fair value Table 8.2 September 30, 2023 December 31, 2022 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Financial assets Other invested assets $ 850 $ 850 $ 850 $ 850 Financial liabilities 5.25% Senior Notes 642,828 605,976 641,724 600,938 9% Convertible Junior Subordinated Debentures — — 21,086 28,085 Total financial liabilities $ 642,828 $ 605,976 $ 662,810 $ 629,023

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2023
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income	The pretax and related income tax benefit (expense) components of our other comprehensive income (loss) for the three and nine months ended September 30, 2023 and 2022 are included in table 9.1 below. Components of other comprehensive income (loss) Table 9.1 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2023 2022 2023 2022 Net unrealized investment (losses) gains arising during the period $ (95,216) $ (194,449) $ (31,387) $ (759,409) Total income tax benefit (expense) 19,995 40,834 6,591 159,476 Net of taxes (75,221) (153,615) (24,796) (599,933) Net changes in benefit plan assets and obligations 4,067 (20,471) 11,914 (19,353) Total income tax benefit (expense) (854) 4,299 (2,502) 4,064 Net of taxes 3,213 (16,172) 9,412 (15,289) Total other comprehensive income (loss) $ (91,149) (214,920) (19,473) (778,762) Total income tax benefit (expense) 19,141 45,133 4,089 163,540 Total other comprehensive income (loss), net of tax $ (72,008) $ (169,787) $ (15,384) $ (615,222)
Reclassification out of accumulated other comprehensive income	The pretax and related income tax benefit (expense) components of the amounts reclassified from our accumulated other comprehensive income (loss) (“AOCI”) to our consolidated statements of operations for the three and nine months ended September 30, 2023 and 2022 are included in table 9.2 below. Reclassifications from AOCI Table 9.2 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2023 2022 2023 2022 Reclassification adjustment for net realized (losses) gains (1) $ (3,085) $ (6,681) $ (13,020) $ (4,273) Income tax benefit (expense) 648 1,403 2,734 897 Net of taxes (2,437) (5,278) (10,286) (3,376) Reclassification adjustment related to benefit plan assets and obligations (2) (2,376) (6,228) (12,379) (7,346) Income tax benefit (expense) 499 1,308 2,600 1,543 Net of taxes (1,877) (4,920) (9,779) (5,803) Total reclassifications (5,461) (12,909) (25,399) (11,619) Income tax benefit (expense) 1,147 2,711 5,334 2,440 Total reclassifications, net of tax $ (4,314) $ (10,198) $ (20,065) $ (9,179) (1) Increases (decreases) Net realized investment gains (losses) on the consolidated statements of operations. (2) Decreases (increases) Other underwriting and operating expenses, net on the consolidated statements of operations.
Accumulated other comprehensive income (loss)	A rollforward of AOCI for the nine months ended September 30, 2023, including amounts reclassified from AOCI, are included in table 9.3 below. Rollforward of AOCI Table 9.3 Nine Months Ended September 30, 2023 (In thousands) Net unrealized gains and (losses) on available-for-sale securities Net benefit plan assets and (obligations) recognized in shareholders' equity Total accumulated other comprehensive income (loss) Balance at December 31, 2022, net of tax $ (408,496) $ (73,015) $ (481,511) Other comprehensive income (loss) before reclassifications (35,082) (367) (35,449) Less: Amounts reclassified from AOCI (10,286) (9,779) (20,065) Balance, September 30, 2023, net of tax $ (433,292) $ (63,603) $ (496,895)

Benefit Plans (Tables)

Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Components of net periodic benefit cost	Tables 10.1 and 10.2 provide the components of net periodic benefit cost for our pension, supplemental executive retirement and other postretirement benefit plans for the three and nine months ended September 30, 2023 and 2022. Components of net periodic benefit cost Table 10.1 Three Months Ended September 30, Pension and Supplemental Executive Retirement Plans Other Postretirement Benefit Plans (In thousands) 2023 2022 2023 2022 Company service cost $ — $ 1,813 $ 374 $ 327 Interest cost 3,297 2,863 409 173 Expected return on plan assets (3,426) (4,907) (2,059) (2,625) Amortization of: Net actuarial losses (gains) 529 1,266 (38) (776) Prior service cost (credit) 87 (57) 465 123 Cost of settlements and curtailments 334 5,671 — — Net periodic benefit cost (benefit) $ 821 $ 6,649 $ (849) $ (2,778) Components of net periodic benefit cost Table 10.2 Nine Months Ended September 30, Pension and Supplemental Executive Retirement Plans Other Postretirement Benefit Plans (In thousands) 2023 2022 2023 2022 Company service cost $ — $ 5,439 $ 1,122 $ 981 Interest cost 10,278 8,588 1,225 521 Expected return on plan assets (10,432) (14,723) (6,176) (7,876) Amortization of: Net actuarial losses (gains) 1,656 3,798 (113) (2,328) Prior service cost (credit) 259 (163) 1,396 367 Cost of settlements and curtailments 9,181 5,671 — — Net periodic benefit cost (benefit) $ 10,942 $ 8,610 $ (2,546) $ (8,335)

Loss Reserves (Tables)

Loss Reserves (Tables)	9 Months Ended
	Sep. 30, 2023
Insurance Loss Reserves [Abstract]
Reconciliation of beginning and ending loss reserves	Table 11.1 provides a reconciliation of beginning and ending loss reserves as of and for the nine months ended September 30, 2023 and 2022. Development of reserves for losses and loss adjustment expenses Table 11.1 Nine Months Ended September 30, (In thousands) 2023 2022 Reserve at beginning of period $ 557,988 $ 883,522 Less reinsurance recoverable 28,240 66,905 Net reserve at beginning of period 529,748 816,617 Losses incurred: Losses and LAE incurred in respect of delinquency notices received in: Current year 137,626 104,086 Prior years (1) (148,948) (327,512) Total losses incurred (11,322) (223,426) Losses paid: Losses and LAE paid in respect of delinquency notices received in: Current year 153 116 Prior years 33,679 36,089 Total losses paid 33,832 36,205 Net reserve at end of period 484,594 556,986 Plus reinsurance recoverable 40,934 46,384 Reserve at end of period $ 525,528 $ 603,370 (1) A positive number for prior year loss reserve development indicates a deficiency of prior year reserves. A negative number for prior year loss reserve development indicates a redundancy of prior year loss reserves. See the following table for more information about prior year loss reserve development.
Prior year development of the reserves	The prior year loss reserve development for the nine months ended September 30, 2023 and 2022 is shown in table 11.2 below. Reserve development on previously received delinquencies Table 11.2 Nine Months Ended September 30, (In thousands) 2023 2022 Increase (decrease) in estimated claim rate on primary defaults $ (142,764) $ (324,556) Change in estimates related to severity on primary defaults, pool reserves, LAE reserves, reinsurance, and other (6,184) (2,956) Total prior year loss development (1) $ (148,948) $ (327,512) (1) A positive number for prior year loss reserve development indicates a deficiency of prior year loss reserves. A negative number for prior year loss reserve development indicates a redundancy of prior year loss reserves.
Rollforward of primary delinquent inventory	A rollforward of our primary delinquency inventory for the three and nine months ended September 30, 2023 and 2022 appears in table 11.3 below. The information concerning new notices and cures is compiled from monthly reports received from loan servicers. The level of new notice and cure activity reported in a particular month can be influenced by, among other things, the date on which a servicer generates its report, the number of business days in a month and transfers of servicing between loan servicers. Delinquency inventory rollforward Table 11.3 Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Delinquency inventory at beginning of period 23,823 26,855 26,387 33,290 New notices 12,240 10,990 34,117 31,089 Cures (10,975) (11,494) (34,738) (37,371) Paid claims (359) (337) (1,018) (978) Rescissions and denials (9) (11) (28) (27) Other items removed from inventory — (125) — (125) Delinquency inventory at end of period 24,720 25,878 24,720 25,878
Aging of the primary delinquent inventory	Table 11.4 below shows the number of consecutive months a borrower is delinquent. Historically as a delinquency ages it is more likely to result in a claim. Primary delinquency inventory - consecutive months delinquent Table 11.4 September 30, 2023 December 31, 2022 September 30, 2022 3 months or less 8,732 8,820 7,825 4-11 months 8,220 8,217 7,619 12 months or more (1) 7,768 9,350 10,434 Total 24,720 26,387 25,878 3 months or less 35 % 33 % 30 % 4-11 months 33 % 31 % 30 % 12 months or more 32 % 36 % 40 % Total 100 % 100 % 100 % Primary claims received inventory included in ending delinquent inventory 284 267 244

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of stock-based compensation, activity	Table 13.1 shows the number of restricted stock units (RSUs) granted to employees and non-employee directors and the weighted average fair value per share during the periods presented. Restricted stock unit grants Table 13.1 Nine months ended September 30, 2023 2022 RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs subject to performance conditions (1) 949 $ 14.17 848 $ 15.46 RSUs subject only to service conditions 354 14.17 319 15.45 Non-employee director RSUs 106 14.17 104 15.32 (1) Shares granted are subject to performance conditions under which the target number of shares granted may vest up to 200%.

Statutory Information Statutory

Statutory Information Statutory Information (Tables)	9 Months Ended
	Sep. 30, 2023
Statutory Capital [Abstract]
Summary of amounts disclosed under statutory accounting practices	The statutory net income, policyholders’ surplus, and contingency loss reserves of our insurance subsidiaries, including MGIC, are shown in table 14.1. Financial information of our insurance subsidiaries (including MGIC) Table 14.1 As of and for the Nine Months Ended September 30, (In thousands) 2023 2022 Statutory net income $ 207,996 $ 284,084 Statutory policyholders' surplus 859,083 1,231,992 Contingency loss reserves 5,071,276 4,533,371

Debt - Summary of Debt Obligati

Debt - Summary of Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 642,828	$ 662,810
Senior Notes | 5.25% Senior Notes Due 2028
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 642,828	641,724
Stated interest rate	5.25%
Debt instrument, face amount	$ 650,000
9% Convertible Junior Subordinated Debentures
Debt Instrument [Line Items]
Long-term debt, carrying value	$ 0	$ 21,086
Stated interest rate	9%

Debt - Narrative (Details)

Debt - Narrative (Details) shares in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023 USD ($) shares	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Debt Instrument [Line Items]
Reduction in potentially dilutive shares due to debt extinguishment | shares	1.6
Total interest payments		$ 35,100,000	$ 52,700,000
9% Convertible Junior Subordinated Debentures
Debt Instrument [Line Items]
Extinguishment of debt, amount	$ 21,100,000
Conversion rate (in shares per $1,000 note)		0.077962
Principal amount of notes used in determining conversion rate	1,000	$ 1,000
Redemption of convertible junior subordinated debentures	28,600,000
Reduction in shareholders' equity due to debt conversion	$ (5,300,000)

Reinsurance - Summary of Premiu

Reinsurance - Summary of Premiums Earned and Losses Incurred (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Premiums earned:
Direct	$ 287,640	$ 289,072	$ 858,310	$ 864,191
Assumed	3,801	2,254	9,635	6,501
Ceded	(50,164)	(39,215)	(141,842)	(107,644)
Net premiums earned	241,277	252,111	726,103	763,048
Losses incurred:
Direct	6,627	(112,435)	2,044	(242,861)
Assumed	20	21	(7)	(340)
Losses incurred, net	(77)	(105,054)	(11,322)	(223,426)
Quota Share Reinsurance Transactions
Premiums earned:
Ceded	(32,693)	(19,348)	(90,012)	(56,721)
Losses incurred:
Ceded	(6,724)	7,360	(13,359)	19,775
Profit commission on reinsurance	30,698	47,255	97,218	135,049
Ceding commission on reinsurance	12,678	13,321	37,446	38,355
Excess of Loss Reinsurance Transactions
Premiums earned:
Ceded	$ (17,471)	$ (19,867)	$ (51,830)	$ (50,923)

Reinsurance - Narrative (Detail

Reinsurance - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended
	Oct. 31, 2023	Dec. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2024	Dec. 31, 2022	Dec. 31, 2021
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves			$ 40,934	$ 46,384	$ 40,934	$ 46,384		$ 28,240	$ 66,905
Ceded premiums			$ 50,164	$ 39,215	$ 141,842	$ 107,644
Quota Share Reinsurance Transactions
Effects of Reinsurance [Line Items]
Ceding commission, percentage (as a percent)					20%
Reinsurance, quote share reinsurance agreement, annual loss ratio cap (as a percent)			300%		300%
Reinsurance, quota reinsurance agreement, lifetime loss ratio cap (as a percent)			200%		200%
Threshold for private mortgage insurer eligibility requirements for termination election (less than) (as a percent)					90%
Reinsurance recoverable on loss reserves			$ 40,900		$ 40,900			$ 28,200
Credit Union QSR Transaction
Effects of Reinsurance [Line Items]
Threshold for private mortgage insurer eligibility requirements for termination election (less than) (as a percent)					80%
Quota share for all policies covered (as a percent)					65%
2020 QSR
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)					12.50%
2020 QSR | Forecast
Effects of Reinsurance [Line Items]
Contingent termination fee		$ 5,000
2024 QSR Transaction | Forecast
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)							30%
Excess of Loss Reinsurance Transactions, Home Re Transactions
Effects of Reinsurance [Line Items]
Percent of reinsurance coverage threshold (as a percent)					10%
Home Re 2019-1 | Subsequent Event
Effects of Reinsurance [Line Items]
Reduction to reinsurance agreements	$ 187,100
Home Re 2021-1 | Subsequent Event
Effects of Reinsurance [Line Items]
Reduction to reinsurance agreements	91,100
Home Re 2021-2 | Subsequent Event
Effects of Reinsurance [Line Items]
Reduction to reinsurance agreements	$ 106,700
Home Re 2019-1 Ltd, Home Re 2021-1 Ltd, and Home Re-2021-2 Ltd | Forecast
Effects of Reinsurance [Line Items]
Ceded premiums		$ 8,000
Home Re special purpose insurers
Effects of Reinsurance [Line Items]
Percent of total trust assets invested in cash or direct U.S. federal government obligations					99.50%

Reinsurance - Quota Share Trans

Reinsurance - Quota Share Transactions Terms (Details)	9 Months Ended
	Sep. 30, 2023
2020 QSR
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	12.50%
Loss ratio threshold for profit commissions (as a percent)	62%
Cede rate, option 1 (as a percent)	10.50%
Cede rate, option 2 (as a percent)	8%
2020 and 2021 QSR - 2020 NIW
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	17.50%
Loss ratio threshold for profit commissions (as a percent)	62%
Cede rate, option 1 (as a percent)	14.50%
Cede rate, option 2 (as a percent)	12%
2020 and 2021 QSR - 2021 NIW
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	17.50%
Loss ratio threshold for profit commissions (as a percent)	61.90%
Cede rate, option 1 (as a percent)	14.50%
Cede rate, option 2 (as a percent)	12%
2021 and 2022 QSR - 2021 NIW
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	12.50%
Loss ratio threshold for profit commissions (as a percent)	57.50%
Cede rate, option 1 (as a percent)	10.50%
Cede rate, option 2 (as a percent)	8%
2021 and 2022 QSR - 2022 NIW
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	15%
Loss ratio threshold for profit commissions (as a percent)	57.50%
Cede rate, option 1 (as a percent)	12.50%
Cede rate, option 2 (as a percent)	10%
2022 and 2023 QSR - 2022 NIW
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	15%
Loss ratio threshold for profit commissions (as a percent)	62%
Cede rate, option 1 (as a percent)	12.50%
Cede rate, option 2 (as a percent)	10%
2022 and 2023 QSR - 2023 NIW
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	15%
Loss ratio threshold for profit commissions (as a percent)	62%
Cede rate, option 1 (as a percent)	12.50%
Cede rate, option 2 (as a percent)	10%
2023 QSR
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	10%
Loss ratio threshold for profit commissions (as a percent)	58.50%
Cede rate, option 1 (as a percent)	8%
Cede rate, option 2 (as a percent)	7%
Credit Union QSR Transaction
Effects of Reinsurance [Line Items]
Quota share for all policies covered (as a percent)	65%
Loss ratio threshold for profit commissions (as a percent)	50%

Reinsurance - Excess of Loss Re

Reinsurance - Excess of Loss Reinsurance (Details) - USD ($) $ in Thousands									9 Months Ended	12 Months Ended
	Apr. 01, 2023	Apr. 26, 2022	Apr. 01, 2022	Aug. 03, 2021	Feb. 02, 2021	Oct. 29, 2020	May 25, 2019	Oct. 30, 2018	Sep. 30, 2023	Dec. 31, 2022	Oct. 23, 2023
Home Re 2023-1 | Subsequent Event
Effects of Reinsurance [Line Items]
Excess of loss reinsurance coverage, initial and remaining											$ 330,200
Home Re 2022-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes		12 years 6 months
Initial first layer retention		$ 325,589
Remaining first layer retention									$ 325,104	$ 325,576
Excess of loss reinsurance coverage, initial and remaining		$ 473,575							445,461	473,575
Home Re 2021-2
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes				12 years 6 months
Initial first layer retention				$ 190,159
Remaining first layer retention									189,610	190,097
Excess of loss reinsurance coverage, initial and remaining				$ 398,429					281,919	352,084
Home Re 2021-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes					12 years 6 months
Initial first layer retention					$ 211,159
Remaining first layer retention									210,858	211,102
Excess of loss reinsurance coverage, initial and remaining					$ 398,848				209,311	277,053
Home Re 2020-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes						10 years
Initial first layer retention						$ 275,283
Remaining first layer retention									274,968	275,051
Excess of loss reinsurance coverage, initial and remaining						$ 412,917			53,023	113,247
Home Re 2019-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes							10 years
Initial first layer retention							$ 185,730
Remaining first layer retention									182,791	183,540
Excess of loss reinsurance coverage, initial and remaining							$ 315,739		208,146	208,146
Home Re 2018-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes								10 years
Initial first layer retention								$ 168,691
Remaining first layer retention									164,385	164,849
Excess of loss reinsurance coverage, initial and remaining								$ 318,636	84,819	140,993
2022 Traditional XOL
Effects of Reinsurance [Line Items]
Amortization period excess of loss reinsurance coverage			10 years
Initial first layer retention			$ 82,523
Remaining first layer retention									82,463	82,517
Excess of loss reinsurance coverage, initial and remaining			$ 142,642						$ 142,642	$ 142,642
2023 Traditional XOL
Effects of Reinsurance [Line Items]
Amortization period excess of loss reinsurance coverage	10 years
Excess of loss reinsurance coverage, initial and remaining	$ 116,000

Reinsurance - Variable Interest

Reinsurance - Variable Interest Entity (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Assets	$ 6,331,679	$ 6,213,793
Home Re 2022-1
Effects of Reinsurance [Line Items]
Assets	454,943	473,575
Home Re 2021-2
Effects of Reinsurance [Line Items]
Assets	282,328	357,340
Home Re 2021-1
Effects of Reinsurance [Line Items]
Assets	209,384	285,039
Home Re 2020-1
Effects of Reinsurance [Line Items]
Assets	58,371	119,159
Home Re 2019-1
Effects of Reinsurance [Line Items]
Assets	208,146	208,146
Home Re 2018-1
Effects of Reinsurance [Line Items]
Assets	$ 89,405	$ 146,822

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Basic earnings per share:
Net income	$ 182,844	$ 249,625	$ 528,445	$ 673,906
Weighted average common shares outstanding - basic (in shares)	281,757	302,622	286,184	309,097
Basic earnings per share (in dollars per share)	$ 0.65	$ 0.82	$ 1.85	$ 2.18
Diluted earnings per share:
Net income	$ 182,844	$ 249,625	$ 528,445	$ 673,906
Diluted income available to common shareholders	$ 183,120	$ 250,245	$ 529,470	$ 676,757
Weighted average common shares outstanding - basic (in shares)	281,757	302,622	286,184	309,097
Effect of dilutive securities:
Weighted average common shares outstanding - diluted (in shares)	285,600	307,194	289,924	315,029
Diluted earnings per share (in dollars per share)	$ 0.64	$ 0.81	$ 1.83	$ 2.15
Federal statutory income tax rate (in hundredths)	21%	21%	21%	21%
9% Convertible Junior Subordinated Debentures
Diluted earnings per share:
Dilutive securities	$ 276	$ 620	$ 1,025	$ 2,851
Effect of dilutive securities:
Dilutive securities (in shares)	1,219	2,670	1,501	4,084
Stated interest rate	9%		9%
Unvested RSUs
Effect of dilutive securities:
Unvested RSUs (in shares)	2,624	1,902	2,239	1,848

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 6,130,009	$ 5,926,785
Fair Value	5,581,537	5,409,698
Short term fixed income securities investments held by company	177,400	67,000
Assets held by insurance regulatory requirements	11,500	11,800
Assets held in trust for the benefit of contractual counterparties	143,800	128,400
Total fixed income securities (1)
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,130,009	5,926,785
Gross Unrealized Gains	1,829	5,953
Gross Unrealized Losses	(550,301)	(523,040)
Fair Value	5,581,537	5,409,698
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	220,592	145,581
Gross Unrealized Gains	7	2
Gross Unrealized Losses	(9,765)	(9,683)
Fair Value	210,834	135,900
Obligations of U.S. states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,178,573	2,400,261
Gross Unrealized Gains	1,234	4,866
Gross Unrealized Losses	(274,157)	(256,073)
Fair Value	1,905,650	2,149,054
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,564,817	2,416,475
Gross Unrealized Gains	498	1,043
Gross Unrealized Losses	(200,650)	(196,377)
Fair Value	2,364,665	2,221,141
ABS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	172,262	126,723
Gross Unrealized Gains	9	5
Gross Unrealized Losses	(5,051)	(6,041)
Fair Value	167,220	120,687
RMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	307,402	223,743
Gross Unrealized Gains	7	10
Gross Unrealized Losses	(34,727)	(25,744)
Fair Value	272,682	198,009
CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	297,091	257,785
Gross Unrealized Gains	65	22
Gross Unrealized Losses	(22,836)	(20,591)
Fair Value	274,320	237,216
CLOs
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	333,974	337,656
Gross Unrealized Gains	9	5
Gross Unrealized Losses	(2,256)	(7,829)
Fair Value	331,727	329,832
Foreign government debt
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,486	4,486
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(859)	(699)
Fair Value	3,627	3,787
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,812	14,075
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(3)
Fair Value	$ 50,812	$ 14,072

Investments - Amortized Cost an

Investments - Amortized Cost and Fair Values of Debt Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Amortized cost
Due in one year or less	$ 667,446
Due after one year through five years	1,543,417
Due after five years through ten years	1,805,365
Due after ten years	1,003,052
Total debt securities with single maturity date, amortized cost	5,019,280
Amortized Cost	6,130,009	$ 5,926,785
Fair Value
Due in one year or less	659,512
Due after one year through five years	1,458,444
Due after five years through ten years	1,617,227
Due after ten years	800,405
Total debt securities with single maturity date, fair value	4,535,588
Total at end of period	5,581,537	5,409,698
ABS
Amortized cost
Total debt securities without single maturity date, amortized cost	172,262
Amortized Cost	172,262	126,723
Fair Value
Total debt securities without single maturity date, fair value	167,220
Total at end of period	167,220	120,687
RMBS
Amortized cost
Total debt securities without single maturity date, amortized cost	307,402
Amortized Cost	307,402	223,743
Fair Value
Total debt securities without single maturity date, fair value	272,682
Total at end of period	272,682	198,009
CMBS
Amortized cost
Total debt securities without single maturity date, amortized cost	297,091
Amortized Cost	297,091	257,785
Fair Value
Total debt securities without single maturity date, fair value	274,320
Total at end of period	274,320	237,216
CLOs
Amortized cost
Total debt securities without single maturity date, amortized cost	333,974
Amortized Cost	333,974	337,656
Fair Value
Total debt securities without single maturity date, fair value	331,727
Total at end of period	$ 331,727	$ 329,832

Investments - Equity Securities

Investments - Equity Securities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Cost	$ 15,998	$ 15,924
Gross Gains	0	0
Gross Losses	(2,049)	(1,784)
Equity securities	$ 13,949	$ 14,140

Investments - Net Gains (Losses

Investments - Net Gains (Losses) On Investments and Other Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fixed income securities
Gross realized gains on sales of fixed income securities	$ 2,581	$ 1,667	$ 2,747	$ 6,788
Gross realized losses on sales of fixed income securities	(2,814)	(7,040)	(13,362)	(12,790)
Impairments	0	(1,415)	0	(1,415)
Equity securities gains (losses)
Equity securities, gains (losses), market adjustment	(462)	(617)	(266)	(2,351)
Change in embedded derivative on Home Re Transactions	(7)	4,199	(2,486)	983
Other
Other, gains (losses) on sales	(4)	(66)	(4)	(18)
Other, market adjustment	11	14	(9)	27
Net gains (losses) on investments and other financial instruments	(695)	(3,258)	(13,380)	(8,776)
Proceeds from sales of fixed income securities	$ 24,434	$ 125,186	$ 293,392	$ 388,740

Investments - Securities In Unr

Investments - Securities In Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	$ 1,562,347	$ 3,411,256
12 Months or Greater - Fair Value	3,914,277	1,592,040
Total - Fair Value	5,476,624	5,003,296
Less Than 12 Months - Unrealized Losses	(37,684)	(298,637)
12 Months or Greater - Unrealized Losses	(512,617)	(224,403)
Total - Unrealized Losses	$ (550,301)	$ (523,040)
Number of securities in unrealized loss position (in securities) | security	1,315	1,226
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	$ 64,850	$ 67,531
12 Months or Greater - Fair Value	111,833	76,246
Total - Fair Value	176,683	143,777
Less Than 12 Months - Unrealized Losses	(538)	(3,583)
12 Months or Greater - Unrealized Losses	(9,227)	(6,100)
Total - Unrealized Losses	(9,765)	(9,683)
Obligations of U.S. states and political subdivisions
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	674,000	1,344,272
12 Months or Greater - Fair Value	1,226,433	360,956
Total - Fair Value	1,900,433	1,705,228
Less Than 12 Months - Unrealized Losses	(14,743)	(157,903)
12 Months or Greater - Unrealized Losses	(259,414)	(98,170)
Total - Unrealized Losses	(274,157)	(256,073)
Corporate debt securities
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	600,174	1,488,255
12 Months or Greater - Fair Value	1,745,339	758,732
Total - Fair Value	2,345,513	2,246,987
Less Than 12 Months - Unrealized Losses	(12,938)	(109,976)
12 Months or Greater - Unrealized Losses	(187,712)	(86,401)
Total - Unrealized Losses	(200,650)	(196,377)
ABS
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	74,002	53,201
12 Months or Greater - Fair Value	92,013	67,073
Total - Fair Value	166,015	120,274
Less Than 12 Months - Unrealized Losses	(950)	(1,008)
12 Months or Greater - Unrealized Losses	(4,101)	(5,033)
Total - Unrealized Losses	(5,051)	(6,041)
RMBS
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	116,145	77,563
12 Months or Greater - Fair Value	172,590	136,179
Total - Fair Value	288,735	213,742
Less Than 12 Months - Unrealized Losses	(6,082)	(8,572)
12 Months or Greater - Unrealized Losses	(28,645)	(17,172)
Total - Unrealized Losses	(34,727)	(25,744)
CMBS
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	33,176	166,973
12 Months or Greater - Fair Value	241,908	70,792
Total - Fair Value	275,084	237,765
Less Than 12 Months - Unrealized Losses	(2,433)	(12,951)
12 Months or Greater - Unrealized Losses	(20,403)	(7,640)
Total - Unrealized Losses	(22,836)	(20,591)
CLOs
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	0	213,461
12 Months or Greater - Fair Value	320,534	114,459
Total - Fair Value	320,534	327,920
Less Than 12 Months - Unrealized Losses	0	(4,644)
12 Months or Greater - Unrealized Losses	(2,256)	(3,185)
Total - Unrealized Losses	(2,256)	(7,829)
Foreign government debt
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	0	0
12 Months or Greater - Fair Value	3,627	3,787
Total - Fair Value	3,627	3,787
Less Than 12 Months - Unrealized Losses	0	0
12 Months or Greater - Unrealized Losses	(859)	(699)
Total - Unrealized Losses	$ (859)	(699)
Commercial paper
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value		0
12 Months or Greater - Fair Value		3,816
Total - Fair Value		3,816
Less Than 12 Months - Unrealized Losses		0
12 Months or Greater - Unrealized Losses		(3)
Total - Unrealized Losses		$ (3)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 5,581,537		$ 5,409,698
Equity securities	13,949		14,140
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	13,949		14,140
Cash equivalents	271,924		328,756
Total assets	5,867,410		5,752,594
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	13,949		14,140
Cash equivalents	255,772		324,129
Total assets	410,612		455,166
Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	0		0
Cash equivalents	16,152		4,627
Total assets	5,456,798		5,297,428
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivative related to Home Re transactions	(100)		2,500
Significant Unobservable Inputs (Level 3) | Real Estate Acquired
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchases of real estate assets acquired	100	$ 2,900
Sales of real estate assets acquired	1,600	$ 3,200
Total fixed income securities (1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,581,537		5,409,698
Total fixed income securities (1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,581,537		5,409,698
Total fixed income securities (1) | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	140,891		116,897
Total fixed income securities (1) | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,440,646		5,292,801
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	210,834		135,900
U.S. Treasury securities and obligations of U.S. government corporations and agencies | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	210,834		135,900
U.S. Treasury securities and obligations of U.S. government corporations and agencies | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	140,891		116,897
U.S. Treasury securities and obligations of U.S. government corporations and agencies | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	69,943		19,003
Obligations of U.S. states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1,905,650		2,149,054
Obligations of U.S. states and political subdivisions | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1,905,650		2,149,054
Obligations of U.S. states and political subdivisions | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
Obligations of U.S. states and political subdivisions | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1,905,650		2,149,054
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,364,665		2,221,141
Corporate debt securities | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,364,665		2,221,141
Corporate debt securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
Corporate debt securities | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,364,665		2,221,141
ABS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	167,220		120,687
ABS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	167,220		120,687
ABS | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
ABS | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	167,220		120,687
RMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	272,682		198,009
RMBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	272,682		198,009
RMBS | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
RMBS | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	272,682		198,009
CMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	274,320		237,216
CMBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	274,320		237,216
CMBS | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
CMBS | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	274,320		237,216
CLOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	331,727		329,832
CLOs | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	331,727		329,832
CLOs | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
CLOs | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	331,727		329,832
Foreign government debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	3,627		3,787
Foreign government debt | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	3,627		3,787
Foreign government debt | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
Foreign government debt | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	3,627		3,787
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	50,812		14,072
Commercial paper | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	50,812		14,072
Commercial paper | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0		0
Commercial paper | Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 50,812		$ 14,072

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	$ 850	$ 850
9% Convertible Junior Subordinated Debentures	0	21,086
Total financial liabilities	642,828	662,810
Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	850	850
9% Convertible Junior Subordinated Debentures	0	28,085
Total financial liabilities	$ 605,976	629,023
Senior Notes | 5.25% Senior Notes Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	5.25%
Senior Notes | 5.25% Senior Notes Due 2028 | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes Payable	$ 642,828	641,724
Senior Notes | 5.25% Senior Notes Due 2028 | Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes Payable	$ 605,976	$ 600,938
9% Convertible Junior Subordinated Debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	9%

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	$ (91,149)	$ (214,920)	$ (19,473)	$ (778,762)
Income tax benefit (expense)	19,141	45,133	4,089	163,540
Other comprehensive income (loss), net of tax	(72,008)	(169,787)	(15,384)	(615,222)
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	234,396	314,267	672,382	849,597
Income tax benefit (expense)	(51,552)	(64,642)	(143,937)	(175,691)
Total reclassifications, net of tax	182,844	249,625	528,445	673,906
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(5,461)	(12,909)	(25,399)	(11,619)
Income tax benefit (expense)	1,147	2,711	5,334	2,440
Total reclassifications, net of tax	(4,314)	(10,198)	(20,065)	(9,179)
Accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss), net of tax	(72,008)	(169,787)	(15,384)	(615,222)
Net unrealized gains and (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	(95,216)	(194,449)	(31,387)	(759,409)
Income tax benefit (expense)	19,995	40,834	6,591	159,476
Other comprehensive income (loss), net of tax	(75,221)	(153,615)	(24,796)	(599,933)
Net unrealized gains and (losses) on available-for-sale securities | Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(3,085)	(6,681)	(13,020)	(4,273)
Income tax benefit (expense)	648	1,403	2,734	897
Total reclassifications, net of tax	(2,437)	(5,278)	(10,286)	(3,376)
Net benefit plan assets and (obligations) recognized in shareholders' equity
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	4,067	(20,471)	11,914	(19,353)
Income tax benefit (expense)	(854)	4,299	(2,502)	4,064
Other comprehensive income (loss), net of tax	3,213	(16,172)	9,412	(15,289)
Net benefit plan assets and (obligations) recognized in shareholders' equity | Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(2,376)	(6,228)	(12,379)	(7,346)
Income tax benefit (expense)	499	1,308	2,600	1,543
Total reclassifications, net of tax	$ (1,877)	$ (4,920)	$ (9,779)	$ (5,803)

Other Comprehensive Income - Ro

Other Comprehensive Income - Rollforward of AOCI (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	$ 4,642,740
Other comprehensive income (loss) before reclassifications	(35,449)
Less: Amounts reclassified from AOCI	(20,065)
Balance, end of period	4,854,705
Accumulated other comprehensive income (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(481,511)
Balance, end of period	(496,895)
Net unrealized gains and (losses) on available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(408,496)
Other comprehensive income (loss) before reclassifications	(35,082)
Less: Amounts reclassified from AOCI	(10,286)
Balance, end of period	(433,292)
Net benefit plan assets and (obligations) recognized in shareholders' equity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(73,015)
Other comprehensive income (loss) before reclassifications	(367)
Less: Amounts reclassified from AOCI	(9,779)
Balance, end of period	$ (63,603)

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension and Supplemental Executive Retirement Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	$ 0	$ 1,813	$ 0	$ 5,439
Interest cost	3,297	2,863	10,278	8,588
Expected return on plan assets	(3,426)	(4,907)	(10,432)	(14,723)
Net actuarial losses (gains)	529	1,266	1,656	3,798
Prior service cost (credit)	87	(57)	259	(163)
Cost of settlements and curtailments	334	5,671	9,181	5,671
Net periodic benefit cost (benefit)	821	6,649	10,942	8,610
Other Postretirement Benefit Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	374	327	1,122	981
Interest cost	409	173	1,225	521
Expected return on plan assets	(2,059)	(2,625)	(6,176)	(7,876)
Net actuarial losses (gains)	(38)	(776)	(113)	(2,328)
Prior service cost (credit)	465	123	1,396	367
Cost of settlements and curtailments	0	0	0	0
Net periodic benefit cost (benefit)	$ (849)	$ (2,778)	$ (2,546)	$ (8,335)

Loss Reserves (Details)

Loss Reserves (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) loan	Sep. 30, 2022 loan	Sep. 30, 2023 USD ($) loan	Sep. 30, 2022 USD ($) loan	Dec. 31, 2022 USD ($)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves | $			$ (32,460)	$ (280,152)
Losses incurred related to prior year notices | $			(148,948)	$ (327,512)
Premium refund liability, expected claim payments | $	$ 19,600		$ 19,600		$ 25,500
Primary Delinquent Inventory [Roll Forward]
Delinquent inventory at the beginning of period (in loans) | loan	23,823	26,855	26,387	33,290
New notices (in loans) | loan	12,240	10,990	34,117	31,089
Cures (in loans) | loan	(10,975)	(11,494)	(34,738)	(37,371)
Paid claims (in loans) | loan	(359)	(337)	(1,018)	(978)
Rescissions and denials (in loans) | loan	(9)	(11)	(28)	(27)
Other items removed from inventory (in loans) | loan	0	(125)	0	(125)
Delinquent inventory at end of period (in loans) | loan	24,720	25,878	24,720	25,878
$1,000 Increase/Decrease In Average Severity Reserve Factor
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves | $			$ 9,000
One Percentage Point Increase/Decrease In Average Claim Rate Reserve Factor
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves | $			15,000
Increase (decrease) in estimated claim rate on primary defaults
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Losses incurred related to prior year notices | $			(142,764)	$ (324,556)
Change in estimates related to severity on primary defaults, pool reserves, LAE reserves, reinsurance, and other
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Losses incurred related to prior year notices | $			$ (6,184)	$ (2,956)

Loss Reserves - Reconciliation

Loss Reserves - Reconciliation of Beginning and Ending Balances (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Loss Reserve [Roll Forward]
Reserve at beginning of period	$ 557,988	$ 883,522
Less reinsurance recoverable	28,240	66,905
Net reserve at beginning of period	529,748	816,617
Losses and LAE incurred in respect of delinquency notices received in:
Current year	137,626	104,086
Prior years	(148,948)	(327,512)
Total losses incurred	(11,322)	(223,426)
Losses and LAE paid in respect of delinquency notices received in:
Current year	153	116
Prior years	33,679	36,089
Total losses paid	33,832	36,205
Net reserve at end of period	484,594	556,986
Plus reinsurance recoverable	40,934	46,384
Reserve at end of period	$ 525,528	$ 603,370

Loss Reserves - Delinquent Item

Loss Reserves - Delinquent Items (Details) - loan	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Aging of the Primary Delinquent Inventory [Abstract]
3 months or less (in loans)	8,732		8,820	7,825
4 - 11 months (in loans)	8,220		8,217	7,619
12 months or more (in loans)	7,768		9,350	10,434
Total primary delinquent inventory (in loans)	24,720	23,823	26,387	25,878	26,855	33,290
3 months or less (as a percent)	35%		33%	30%
4 - 11 months (as a percent)	33%		31%	30%
12 months or more (as a percent)	32%		36%	40%
Total primary delinquent inventory (as a percent)	100%		100%	100%
Primary claims received inventory included in ending delinquent inventory (in loans)	284		267	244
Percent of 12 months or more delinquent inventory, delinquent for more than 36 months (as a percent)	39%		36%	33%

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		1 Months Ended		3 Months Ended	6 Months Ended	9 Months Ended		12 Months Ended
	Oct. 26, 2023	Oct. 27, 2023	Aug. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Class of Stock [Line Items]
Shares repurchased in period (in shares)						14.7		27.8
Shares repurchased, weighted average price per share						$ 14.83		$ 13.89
Remaining authorized repurchase amount				$ 396,000		$ 396,000
Stock repurchase program, authorized amount through 2025				500,000		500,000
Repurchase of common stock						$ 216,693	$ 303,060
Quarterly cash dividend paid (per share)					$ 0.10
Cash dividends			$ 32,900		$ 58,800
Quarterly cash dividend declared (per share)			$ 0.115
9% Convertible Junior Subordinated Debentures
Class of Stock [Line Items]
Extinguishment of debt, amount				21,100
Reduction in shareholders' equity due to debt conversion				$ (5,300)
Subsequent Event
Class of Stock [Line Items]
Shares repurchased in period (in shares)		2.2
Repurchase of common stock		$ 36,500
Quarterly cash dividend declared (per share)	$ 0.115

Share-Based Compensation (Detai

Share-Based Compensation (Details) - $ / shares shares in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
RSUs subject to performance conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	949	848
Weighted Average Share Fair Value (in dollars per share)	$ 14.17	$ 15.46
Share-based compensation arrangement, maximum vesting percent of shares granted	200%
RSUs subject only to service conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	354	319
Weighted Average Share Fair Value (in dollars per share)	$ 14.17	$ 15.45
Non-employee director RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	106	104
Weighted Average Share Fair Value (in dollars per share)	$ 14.17	$ 15.32
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years

Statutory Information (Details)

Statutory Information (Details) $ in Millions	1 Months Ended	9 Months Ended
	Oct. 31, 2023 USD ($)	Sep. 30, 2023 USD ($) jurisdiction
Statutory capital requirements [Abstract]
Number of jurisdictions with risk-to-capital requirements (in jurisdictions) | jurisdiction		16
Maximum permitted risk-to-capital ratio commonly applied		25 to 1
Mortgage Guaranty Insurance Corporation
Statutory capital requirements [Abstract]
Maximum risk-to-capital ratio		25
Risk to capital ratio at end of period		9.6 to 1
Risk-to-capital ratio		9.6
Amount of policyholders position above or below required MPP		$ 3,800
Amount of required MPP		$ 2,100
Percentage of statutory policyholders surplus used to determine maximum allowable dividends (as a percent)		10%
Adjusted statutory net income measurement period (in years)		3 years
Adjusted statutory net income dividend payment measurement period (in years)		2 years
Dividend paid to MGIC Investment Corporation		$ 300
Mortgage Guaranty Insurance Corporation | Subsequent Event
Statutory capital requirements [Abstract]
Dividend paid to MGIC Investment Corporation	$ 300

Statutory Information - Summary

Statutory Information - Summary of Amounts Disclosed Under Statutory Accounting Practices (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Statutory Capital [Abstract]
Statutory net income	$ 207,996	$ 284,084
Statutory policyholders' surplus	859,083	1,231,992
Contingency loss reserves	$ 5,071,276	$ 4,533,371