MGIC Investment (MTG) 10-Q 4 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Oct. 31, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
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		253,365,363
Entity Central Index Key	0000876437
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Investment portfolio:
Fixed income available-for-sale	$ 5,964,065	$ 5,723,113
Equity securities, at fair value (cost 2024 - $16,115; 2023 - $16,025)	15,174	14,771
Other invested assets, at cost	1,109	850
Total investment portfolio	5,980,348	5,738,734
Cash and cash equivalents	288,622	363,666
Restricted cash and cash equivalents	10,987	6,978
Accrued investment income	59,409	58,774
Reinsurance recoverable on loss reserves	45,327	33,302
Reinsurance recoverable on paid losses	992	9,896
Premiums receivable	58,125	58,499
Home office and equipment, net	36,223	38,755
Deferred insurance policy acquisition costs	12,508	14,591
Deferred income taxes, net	56,023	79,782
Other assets	129,220	135,403
Total assets	6,677,784	6,538,380
Liabilities:
Loss reserves	460,574	505,379
Unearned premiums	129,551	157,779
Senior notes	644,299	643,196
Other liabilities	149,284	160,009
Total liabilities	1,383,708	1,466,363
Contingencies
Shareholders’ equity:
Common stock	371,353	371,353
Paid-in capital	1,801,788	1,808,113
Treasury stock at cost	(1,748,895)	(1,384,293)
Accumulated other comprehensive income (loss), net of tax	(204,061)	(316,281)
Retained earnings	5,073,891	4,593,125
Total shareholders’ equity	5,294,076	5,072,017
Total liabilities and shareholders’ equity	6,677,784	6,538,380
Fixed income
Investment portfolio:
Fixed income available-for-sale	5,691,717	5,601,540
Short-Term Investments
Investment portfolio:
Fixed income available-for-sale	$ 272,348	$ 121,573

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fixed maturities, amortized cost	$ 6,161,970	$ 6,061,022
Cost	$ 16,115	$ 16,025
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)	256,216,000	272,494,000
Treasury stock at cost (in shares)	115,137,000	98,859,000
Fixed income
Fixed maturities, amortized cost	$ 5,890,029	$ 5,939,483
Short-Term Investments
Fixed maturities, amortized cost	$ 271,941	$ 121,539

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Premiums written:
Direct	$ 275,124	$ 280,885	$ 823,664	$ 828,211
Assumed	3,602	3,770	10,371	9,538
Ceded	(44,720)	(50,164)	(132,751)	(141,842)
Net premiums written	234,006	234,491	701,284	695,907
Decrease in unearned premiums, net	9,334	6,786	28,228	30,196
Net premiums earned	243,340	241,277	729,512	726,103
Investment income, net of expenses	62,093	55,375	183,316	156,938
Net gains (losses) on investments and other financial instruments	583	(695)	(8,202)	(13,380)
Other revenue	633	548	1,661	1,484
Total revenues	306,649	296,505	906,287	871,145
Losses and expenses:
Losses incurred, net	(9,842)	(77)	(23,559)	(11,322)
Amortization of deferred insurance policy acquisition costs	2,323	2,802	6,482	7,889
Other underwriting and operating expenses, net	50,967	50,130	162,660	174,191
Interest expense	8,905	9,254	26,703	28,005
Total losses and expenses	52,353	62,109	172,286	198,763
Income before tax	254,296	234,396	734,001	672,382
Provision for income tax	54,327	51,552	155,707	143,937
Net income	$ 199,969	$ 182,844	$ 578,294	$ 528,445
Earnings per share:
Basic (in dollars per share)	$ 0.77	$ 0.65	$ 2.18	$ 1.85
Diluted (in dollars per share)	$ 0.77	$ 0.64	$ 2.17	$ 1.83
Weighted average common shares outstanding - basic (in shares)	258,596	281,757	264,719	286,184
Weighted average common shares outstanding - diluted (in shares)	260,833	285,600	266,915	289,924

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 199,969	$ 182,844	$ 578,294	$ 528,445
Other comprehensive income (loss), net of tax:
Change in unrealized investment gains and losses	128,455	(75,221)	110,604	(24,796)
Benefit plan adjustments	539	3,213	1,616	9,412
Other comprehensive income (loss), net of tax	128,994	(72,008)	112,220	(15,384)
Comprehensive income (loss)	$ 328,963	$ 110,836	$ 690,514	$ 513,061

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, 2022		$ 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 Dec. 31, 2022		371,353	1,798,842	(1,050,238)	(481,511)	4,004,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock	(340,600)
Balance, end of period at Dec. 31, 2023	5,072,017	371,353	1,808,113	(1,384,293)	(316,281)	4,593,125
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
Balance, beginning of period at Dec. 31, 2023	5,072,017	371,353	1,808,113	(1,384,293)	(316,281)	4,593,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends	(63,300)
Balance, end of period at Jun. 30, 2024		371,353	1,795,231	(1,624,791)	(333,055)	4,908,183
Balance, beginning of period at Dec. 31, 2023	5,072,017	371,353	1,808,113	(1,384,293)	(316,281)	4,593,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			(31,168)	12,122
Reduction in shareholders' equity due to debt conversion			0
Equity compensation			24,843
Repurchase of common stock	(373,200)			(376,724)
Other comprehensive income (loss), net of tax	112,220				112,220
Net income	578,294					578,294
Cash dividends						(97,528)
Balance, end of period at Sep. 30, 2024	5,294,076	371,353	1,801,788	(1,748,895)	(204,061)	5,073,891
Balance, beginning of period at Jun. 30, 2024		371,353	1,795,231	(1,624,791)	(333,055)	4,908,183
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury stock, net under share-based compensation plans			0	0
Reduction in shareholders' equity due to debt conversion			0
Equity compensation			6,557
Repurchase of common stock				(124,104)
Other comprehensive income (loss), net of tax	128,994				128,994
Net income	199,969					199,969
Cash dividends	(34,200)					(34,261)
Balance, end of period at Sep. 30, 2024	$ 5,294,076	$ 371,353	$ 1,801,788	$ (1,748,895)	$ (204,061)	$ 5,073,891

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income	$ 578,294	$ 528,445
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,403	29,004
Deferred tax expense (benefit)	2,744	(3,172)
Equity compensation	24,843	23,089
Net (gains) losses on investments and other financial instruments	8,202	13,380
Change in certain assets and liabilities:
Accrued investment income	(635)	(3,321)
Reinsurance recoverable on loss reserves	(12,025)	(12,694)
Reinsurance recoverable on paid losses	8,904	17,816
Premiums receivable	374	394
Deferred insurance policy acquisition costs	2,083	3,157
Loss reserves	(44,805)	(32,460)
Unearned premiums	(28,228)	(30,196)
Return premium accrual	(6,700)	(5,900)
Current income taxes	35,944	(2,130)
Other, net	(40,744)	1,304
Net cash provided by (used in) operating activities	542,654	526,716
Cash flows from investing activities:
Purchases of investments	(1,114,276)	(1,220,219)
Proceeds from sales of investments	29,742	294,202
Proceeds from maturity of fixed income securities	962,952	686,552
Proceeds from sale of equipment	0	166
Additions to property and equipment	(660)	(1,455)
Net cash provided by (used in) investing activities	(122,242)	(240,754)
Cash flows from financing activities:
Conversion/purchase of 9% convertible junior debentures	0	(28,637)
Repurchase of common stock	(374,814)	(216,693)
Dividends paid	(97,587)	(91,174)
Payment of withholding taxes related to share-based compensation net share settlement	(19,046)	(7,246)
Net cash provided by (used in) financing activities	(491,447)	(343,750)
Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents	(71,035)	(57,788)
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	370,644	332,913
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$ 299,609	$ 275,125

Nature of Business and Basis of

Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2024
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, 2023 included in our 2023 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, 2024. 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 generally are based on an insurer's book of risk in force, and calculated from tables of factors with several risk dimensions, reduced for credit given for risk ceded under reinsurance agreements). Based on our interpretation of the PMIERs, as of September 30, 2024, 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, 2024
Accounting Standards Update and Change in Accounting Principle [Abstract]
Significant Accounting Policies	Significant Accounting Policies Prospective accounting and reporting developments Relevant new amendments to accounting standards, which are not yet effective or adopted. Segment Reporting—Improvements to Reportable Segment Disclosures: ASU 2023-07 In November 2023, the FASB issued ASU 2023-07. The update expands annual and interim disclosure requirements for reportable segments, primarily through enhanced disclosures about significant segment expenses. The standard will take effect for all public business entities for fiscal periods beginning after December 15, 2023, and interim periods beginning after December 31, 2024. We are currently evaluating the impacts the adoption of this guidance will have on our disclosures. Improvements to Income Tax Disclosures: ASU 2023-09

Debt

Debt	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Debt	Debt Debt obligations The aggregate carrying value of our 5.25% Senior Notes (“5.25% Notes”) and the par value as of September 30, 2024 and December 31, 2023 is presented in table 3.1 below. Long-term debt obligation, carrying value Table 3.1 (In thousands) September 30, 2024 December 31, 2023 5.25% Notes, due August 2028 (par value: $650 million) $ 644,299 $ 643,196 The 5.25% Notes are an obligation of our holding company, MGIC Investment Corporation. See Note 7 - “Debt” in our Annual Report on Form 10-K for the year ended December 31, 2023 for additional information pertaining to our debt obligation. As of September 30, 2024 we are in compliance with our debt covenants. Interest payments

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2024
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) 2024 2023 2024 2023 Premiums earned: Direct $ 284,435 $ 287,640 $ 851,819 $ 858,310 Assumed 3,625 3,801 10,444 9,635 Ceded: Ceded - quota share reinsurance (1) (27,785) (32,693) (83,143) (90,012) Ceded - excess-of-loss reinsurance (16,935) (17,471) (49,608) (51,830) Total ceded (44,720) (50,164) (132,751) (141,842) Net premiums earned $ 243,340 $ 241,277 $ 729,512 $ 726,103 Losses incurred: Direct $ (5,899) $ 6,627 $ (9,116) $ 2,044 Assumed 30 20 13 (7) Ceded - quota share reinsurance (3,973) (6,724) (14,456) (13,359) Losses incurred, net $ (9,842) $ (77) $ (23,559) $ (11,322) Other Reinsurance Impacts: Profit commission on quota share reinsurance (1) $ 28,620 $ 30,698 $ 80,505 $ 97,218 Ceding commission on quota share reinsurance 11,281 12,678 32,730 37,446 (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 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 certain annual loss ratios as defined below. Ceded losses incurred are impacted by the delinquencies covered by our QSR Transactions, our estimates of payments that will be ultimately made on those delinquencies, and claim payments covered by our QSR Transactions. Each of our QSR Transactions typically have annual loss ratio caps of 300% and lifetime loss ratio caps 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 and 2021 QSR 2021 17.5 % 61.9 % December 31, 2032 (2) 2021 QSR and 2022 QSR 2021 12.5 % 57.5 % December 31, 2032 (2) 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 2024 QSR 2024 30.0 % 56.0 % ' December 31, 2035 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. (2) We have elected to terminate our 2021 QSR transaction effective December 31, 2024. 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 and 2021 QSR 2021 December 31, 2024 (3) N/A N/A 2021 QSR and 2022 QSR 2021 December 31, 2024 (3) N/A N/A 2021 QSR and 2022 QSR 2022 December 31, 2024 January 1, 2025 12.5% or 10% 2022 QSR and 2023 QSR 2022 December 31, 2024 January 1, 2025 12.5% or 10% 2022 QSR and 2023 QSR 2023 December 31, 2025 January 1, 2025 12.5% or 10% 2023 QSR 2023 December 31, 2025 January 1, 2025 8% or 7% 2024 QSR 2024 December 31, 2027 December 31, 2027 23% or 15% (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. (3) We have elected to terminate our 2021 QSR transaction effective December 31, 2024, and we expect to incur an early termination fee in the fourth quarter of approximately $8 million. We have agreed upon terms of a 40% QSR transaction with a group of unaffiliated reinsurers covering most of our new insurance written in 2025 and 2026. 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 $45.3 million as of September 30, 2024 and $33.3 million as of December 31, 2023. 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”). For policies covered under our Traditional XOL Transactions, 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 under 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 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, 2024, 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 January and September 2024, we exercised our optional call feature to terminate the reinsurance agreement with Home Re 2020-1, Ltd. and Home Re 2018-1, Ltd., respectively. In connection with the terminations, the insurance linked notes issued by Home Re 2020-1 Ltd. and Home Re 2018-1, Ltd. were redeemed in full. Table 4.4a, 4.4b, and 4.4c provide a summary of our XOL Transactions as of September 30, 2024 and December 31, 2023. Tables 4.4b and 4.4c exclude the 2024 Traditional XOL which is still in its fill up period. Excess of Loss Reinsurance Table 4.4a Issue Date Policy In force Dates Optional Call Date (1) Legal Maturity 2024 Traditional XOL (2) April 1, 2024 January 1, 2024 - December 31, 2024 January 1, 2030 10 years 2023 Traditional XOL April 1, 2023 January 1, 2023 - December 29, 2023 January 1, 2031 10 years 2022 Traditional XOL April 1, 2022 January 1, 2022 - December 30, 2022 January 1, 2030 10 years Home Re 2023-1, Ltd. October 23, 2023 June 1, 2022 - August 31, 2023 October 25, 2028 10 years Home Re 2022-1, Ltd. April 26, 2022 May 29, 2021 - December 31, 2021 April 25, 2028 12.5 years Home Re 2021-2, Ltd. August 3, 2021 January 1, 2021 - May 28, 2021 July 25, 2028 12.5 years Home Re 2021-1, Ltd. February 2, 2021 August 1, 2020 - December 31, 2020 January 25, 2028 12.5 years Home Re 2019-1, Ltd. May 25, 2019 January 1, 2018 - March 31, 2019 May 25, 2026 10 years (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 2024 Traditional XOL Transaction provides up to $187 million of reinsurance coverage on eligible NIW in 2024. Excess of Loss Reinsurance Table 4.4b Remaining First Layer Retention ($ in thousands) Initial First Layer Retention September 30, 2024 December 31, 2023 2023 Traditional XOL $ 70,578 $ 70,516 $ 70,578 2022 Traditional XOL 82,523 81,653 82,346 Home Re 2023-1, Ltd. 272,961 272,633 272,961 Home Re 2022-1, Ltd. 325,589 323,269 325,001 Home Re 2021-2, Ltd. 190,159 188,803 189,403 Home Re 2021-1, Ltd. 211,159 210,303 210,831 Home Re 2019-1, Ltd. 185,730 182,220 182,722 Table 4.4c Remaining Excess of Loss Reinsurance Coverage (1) ($ in thousands) Initial Excess of Loss Reinsurance Coverage (1) Initial Funding Percentage (2) Funding Percentage at 9/30/2024 (2) September 30, 2024 December 31, 2023 2023 Traditional XOL $ 96,942 N/A N/A $ 92,768 $ 96,942 2022 Traditional XOL 142,642 N/A N/A 129,315 142,642 Home Re 2023-1, Ltd. 330,277 97 % 97 % 316,783 330,277 Home Re 2022-1, Ltd. 473,575 100 % 100 % 330,904 420,731 Home Re 2021-2, Ltd. (3) 398,429 100 % 82 % 145,737 173,960 Home Re 2021-1, Ltd. 398,848 100 % 100 % 110,373 117,982 Home Re 2019-1, Ltd. (3) 315,739 100 % 10 % 21,039 21,039 (1) The initial and remaining excess of loss reinsurance coverage is reduced by the applicable funding percentage. (2) The funding percentage represents the aggregate outstanding note balances divided by the aggregate ending coverage amounts. (3) The funding percentage on the 2021-2 and 2019-1 were reduced from 100% after the tender offers were conducted in the fourth quarter of 2023. 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 and used to collateralize the Home Re Entity’s reinsurance obligation to MGIC. The amount of monthly reinsurance coverage premium ceded 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. 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, 2024 and December 31, 2023, were not material to our consolidated balance sheet and the change in fair value during the three and nine months ended September 30, 2024 and September 30, 2023 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, outside the terms of the reinsurance agreement, 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, 2024, and December 31, 2023, 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, 2024 and December 31, 2023. Home Re total assets Table 4.5 (In thousands) Total VIE Assets Home Re Entity September 30, 2024 December 31, 2023 Home Re 2023-1 Ltd. $ 322,780 $ 330,277 Home Re 2022-1 Ltd. 340,486 427,279 Home Re 2021-2 Ltd. 150,540 174,431 Home Re 2021-1 Ltd. 117,315 118,043 Home Re 2019-1 Ltd. 21,039 21,039 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, 2024
Commitments and Contingencies Disclosure [Abstract]
Litigation and Contingencies	Litigation and Contingencies We operate in a highly regulated industry that is subject to the risk of litigation and regulatory proceedings, including related to our claims paying practices. 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 condition or results of operations.

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2024
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, including participating securities. Our “participating securities” are comprised of vested restricted stock and restricted stock units (“RSUs”) with non-forfeitable rights to dividends. Diluted EPS includes the components of basic EPS and also gives effect to dilutive common stock equivalents. 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 would have occurred if our 9% Debentures resulted 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. 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) 2024 2023 2024 2023 Basic earnings per share: Net income $ 199,969 $ 182,844 $ 578,294 $ 528,445 Weighted average common shares outstanding - basic 258,596 281,757 264,719 286,184 Basic earnings per share $ 0.77 $ 0.65 $ 2.18 $ 1.85 Diluted earnings per share: Net income $ 199,969 $ 182,844 $ 578,294 $ 528,445 Interest expense, net of tax: (1) 9% Debentures — 276 — 1,025 Diluted income available to common shareholders $ 199,969 $ 183,120 $ 578,294 $ 529,470 Weighted average common shares outstanding - basic 258,596 281,757 264,719 286,184 Effect of dilutive securities: Unvested RSUs 2,237 2,624 2,196 2,239 9% Debentures — 1,219 — 1,501 Weighted average common shares outstanding - diluted 260,833 285,600 266,915 289,924 Diluted earnings per share $ 0.77 $ 0.64 $ 2.17 $ 1.83 (1) Interest expense has been tax effected at a rate of 21%.

Investments

Investments	9 Months Ended
	Sep. 30, 2024
Investments [Abstract]
Investments	Investments Fixed income securities Our fixed income securities classified as available-for-sale at September 30, 2024 and December 31, 2023 are shown in tables 7.1a and 7.1b below. Details of fixed income securities by category as of September 30, 2024 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 $ 257,572 $ 741 $ (4,019) $ 254,294 Obligations of U.S. states and political subdivisions 2,066,711 7,881 (144,890) 1,929,702 Corporate debt securities 2,774,109 40,041 (84,005) 2,730,145 ABS 156,008 3,339 (1,397) 157,950 RMBS 379,184 9,467 (18,216) 370,435 CMBS 270,014 449 (6,927) 263,536 CLOs 236,816 221 (53) 236,984 Foreign government debt 4,487 — (537) 3,950 Commercial paper 17,069 — — 17,069 Total fixed income securities $ 6,161,970 $ 62,139 $ (260,044) $ 5,964,065 Details of fixed income securities by category as of December 31, 2023 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 $ 167,995 $ 51 $ (6,364) $ 161,682 Obligations of U.S. states and political subdivisions 2,092,754 5,159 (189,835) 1,908,078 Corporate debt securities 2,626,401 17,391 (128,211) 2,515,581 ABS 173,256 1,292 (3,275) 171,273 RMBS 347,132 4,297 (20,656) 330,773 CMBS 293,204 5 (15,752) 277,457 CLOs 327,467 37 (1,408) 326,096 Foreign government debt 4,486 — (643) 3,843 Commercial paper 28,327 3 — 28,330 Total fixed income securities $ 6,061,022 $ 28,235 $ (366,144) $ 5,723,113 We had $12.5 million and $12.2 million of investments at fair value on deposit with various states as of September 30, 2024 and December 31, 2023, respectively, due to regulatory requirements of those state insurance departments. In connection with our insurance and reinsurance activities within MAC and MIC, we are required to maintain assets in trusts for the benefit of contractual counterparties, which had investments at fair value of $198.4 million and $156.9 million at September 30, 2024 and December 31, 2023, respectively. The amortized cost and fair values of fixed income securities at September 30, 2024, 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 periodic payments throughout their lives, they are listed in separate categories. Fixed income securities maturity schedule Table 7.2 September 30, 2024 (In thousands) Amortized cost Fair Value Due in one year or less $ 728,611 $ 727,027 Due after one year through five years 1,567,925 1,554,767 Due after five years through ten years 1,816,994 1,744,159 Due after ten years 1,006,418 909,207 5,119,948 4,935,160 ABS 156,008 157,950 RMBS 379,184 370,435 CMBS 270,014 263,536 CLOs 236,816 236,984 Total $ 6,161,970 $ 5,964,065 Equity securities The cost and fair value of investments in equity securities at September 30, 2024 and December 31, 2023 are shown in tables 7.3a and 7.3b below. Details of equity security investments as of September 30, 2024 Table 7.3a (In thousands) Cost Fair Value Gains Fair Value Losses Fair Value Equity securities $ 16,115 $ 34 $ (975) $ 15,174 Details of equity security investments as of December 31, 2023 Table 7.3b (In thousands) Cost Fair Value Gains Fair Value Losses Fair Value Equity securities $ 16,025 $ 5 $ (1,259) $ 14,771 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 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) 2024 2023 2024 2023 Fixed income securities Gains on sales $ 28 $ 2,581 $ 508 $ 2,747 Losses on sales (946) (2,814) (7,693) (13,362) Equity securities gains (losses) Changes in fair value 507 (462) 312 (266) Change in embedded derivative on Home Re Transactions 994 (7) (1,336) (2,486) Other Gains (losses) on sales — (4) 17 (4) Market adjustment — 11 (10) (9) Net gains (losses) on investments and other financial instruments $ 583 $ (695) $ (8,202) $ (13,380) Proceeds from sales of fixed income securities $ 14,856 $ 24,434 $ 29,742 $ 293,392 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, 2024 and December 31, 2023, 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 2023 Annual Report on Form 10-K. Unrealized loss aging for securities by type and length of time as of September 30, 2024 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 $ 11,859 $ (42) $ 78,089 $ (3,977) $ 89,948 $ (4,019) Obligations of U.S. states and political subdivisions 94,516 (1,481) 1,235,787 (143,409) 1,330,303 (144,890) Corporate debt securities 240,691 (4,040) 1,152,482 (79,965) 1,393,173 (84,005) ABS 43,761 (852) 26,459 (545) 70,220 (1,397) RMBS 53,033 (4,602) 168,955 (13,614) 221,988 (18,216) CMBS 4,829 (76) 220,234 (6,851) 225,063 (6,927) CLOs 82,196 (53) — — 82,196 (53) Foreign government debt — — 3,950 (537) 3,950 (537) Total $ 530,885 $ (11,146) $ 2,885,956 $ (248,898) $ 3,416,841 $ (260,044) Unrealized loss aging for securities by type and length of time as of December 31, 2023 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 $ 26,550 $ (75) $ 98,359 $ (6,289) $ 124,909 $ (6,364) Obligations of U.S. states and political subdivisions 275,727 (3,622) 1,200,533 (186,213) 1,476,260 (189,835) Corporate debt securities 270,956 (6,060) 1,604,021 (122,151) 1,874,977 (128,211) ABS 41,549 (1,234) 62,611 (2,041) 104,160 (3,275) RMBS 44,867 (872) 176,349 (19,784) 221,216 (20,656) CMBS 35,249 (391) 244,216 (15,361) 279,465 (15,752) CLOs — — 274,729 (1,408) 274,729 (1,408) Foreign government debt — — 3,843 (643) 3,843 (643) Total $ 694,898 $ (12,254) $ 3,664,661 $ (353,890) $ 4,359,559 $ (366,144) There were 851 and 1,021 securities in an unrealized loss position at September 30, 2024 and December 31, 2023, respectively. Based on current facts and circumstances, we believe the unrealized losses as of September 30, 2024 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, 2024 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, 2024
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 obtaining relevant trade data, benchmark quotes and spreads and broker/dealer quotes 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: Consist 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, 2024 and December 31, 2023 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 2023 Annual Report on Form 10-K. Assets carried at fair value by hierarchy level as of September 30, 2024 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 $ 254,294 $ 211,991 $ 42,303 Obligations of U.S. states and political subdivisions 1,929,702 — 1,929,702 Corporate debt securities 2,730,145 — 2,730,145 ABS 157,950 — 157,950 RMBS 370,435 — 370,435 CMBS 263,536 — 263,536 CLOs 236,984 — 236,984 Foreign government debt 3,950 — 3,950 Commercial paper 17,069 — 17,069 Total fixed income securities 5,964,065 211,991 5,752,074 Equity securities 15,174 15,174 — Cash equivalents (1) 297,052 271,608 25,444 Total $ 6,276,291 $ 498,773 $ 5,777,518 Assets carried at fair value by hierarchy level as of December 31, 2023 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 $ 161,682 $ 95,828 $ 65,854 Obligations of U.S. states and political subdivisions 1,908,078 — 1,908,078 Corporate debt securities 2,515,581 — 2,515,581 ABS 171,273 — 171,273 RMBS 330,773 — 330,773 CMBS 277,457 — 277,457 CLOs 326,096 — 326,096 Foreign government debt 3,843 — 3,843 Commercial paper 28,330 — 28,330 Total fixed income securities 5,723,113 95,828 5,627,285 Equity securities 14,771 14,771 — Cash equivalents (1) 367,517 367,301 216 Total $ 6,105,401 $ 477,900 $ 5,627,501 (1) Includes restricted cash equivalents Certain financial instruments, including insurance contracts, are excluded from these fair value disclosure requirements. 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, 2024 and December 31, 2023, the fair value of the embedded derivatives was an asset of $1.0 million and$2.4 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, 2024, and 2023, purchases of real estate acquired were $3.7 million and $0.1 million, respectively. For the nine months ended September 30, 2024, and 2023, sales of real estate acquired were $0.6 million and $1.6 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 obligation. The fair value of our 5.25% Notes was based on observable market prices and is 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, 2024 and December 31, 2023. Financial assets and liabilities not measured at fair value Table 8.2 September 30, 2024 December 31, 2023 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Financial assets Other invested assets $ 1,109 $ 1,109 $ 850 $ 850 Financial liabilities 5.25% Senior Notes 644,299 645,983 643,196 634,498

Other Comprehensive Income

Other Comprehensive Income	9 Months Ended
	Sep. 30, 2024
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, 2024 and 2023 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) 2024 2023 2024 2023 Net unrealized investment gains (losses) arising during the period $ 162,601 $ (95,216) $ 140,005 $ (31,387) Total income tax benefit (expense) (34,146) 19,995 (29,401) 6,591 Net of tax 128,455 (75,221) 110,604 (24,796) Net changes in benefit plan assets and obligations 682 4,067 2,045 11,914 Total income tax benefit (expense) (143) (854) (429) (2,502) Net of tax 539 3,213 1,616 9,412 Total other comprehensive income (loss) $ 163,283 (91,149) 142,050 (19,473) Total income tax benefit (expense) (34,289) 19,141 (29,830) 4,089 Total other comprehensive income (loss), net of tax $ 128,994 $ (72,008) $ 112,220 $ (15,384) 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, 2024 and 2023 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) 2024 2023 2024 2023 Reclassification adjustment for net realized (losses) gains (1) $ (2,368) $ (3,085) $ (14,402) $ (13,020) Income tax benefit (expense) 497 648 3,024 2,734 Net of tax (1,871) (2,437) (11,378) (10,286) Reclassification adjustment related to benefit plan assets and obligations (2) (682) (2,376) (2,045) (12,379) Income tax benefit (expense) 143 499 429 2,600 Net of tax (539) (1,877) (1,616) (9,779) Total reclassifications (3,050) (5,461) (16,447) (25,399) Income tax benefit (expense) 640 1,147 3,453 5,334 Total reclassifications, net of tax $ (2,410) $ (4,314) $ (12,994) $ (20,065) (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, 2024, including amounts reclassified from AOCI, are included in table 9.3 below. Rollforward of AOCI Table 9.3 Nine Months Ended September 30, 2024 (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, 2023, net of tax $ (266,948) $ (49,333) $ (316,281) Other comprehensive income (loss) before reclassifications 99,226 — 99,226 Less: Amounts reclassified from AOCI (11,378) (1,616) (12,994) Balance, September 30, 2024, net of tax $ (156,344) $ (47,717) $ (204,061)

Benefit Plans

Benefit Plans	9 Months Ended
	Sep. 30, 2024
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans We have a non-contributory defined benefit pension plan, as well as a supplemental executive retirement plan, that covered eligible employees through December 31, 2022. Effective January 1, 2023, these plans were frozen (no future benefits will be accrued for participants due to employment and no new participants will be added). Participants in these plans were fully vested in their benefits as of December 31, 2022. 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, 2024 and 2023. 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) 2024 2023 2024 2023 Company service cost $ — $ — $ 417 $ 374 Interest cost 3,247 3,297 376 409 Expected return on plan assets (3,644) (3,426) (2,493) (2,059) Amortization of: Net actuarial losses (gains) 522 529 (382) (38) Prior service cost (credit) 87 87 454 465 Cost of settlements and curtailments — 334 — — Net periodic benefit cost (benefit) $ 212 $ 821 $ (1,628) $ (849) 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) 2024 2023 2024 2023 Company service cost $ — $ — $ 1,251 $ 1,122 Interest cost 9,741 10,278 1,126 1,225 Expected return on plan assets (10,932) (10,432) (7,481) (6,176) Amortization of: Net actuarial losses (gains) 1,568 1,656 (1,142) (113) Prior service cost (credit) 259 259 1,360 1,396 Cost of settlements and curtailments — 9,181 — — Net periodic benefit cost (benefit) $ 636 $ 10,942 $ (4,886) $ (2,546) In the first quarter of 2024, we made a contribution to our qualified pension plan of $23.0 million.

Loss Reserves

Loss Reserves	3 Months Ended
	Sep. 30, 2024
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, changes 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, 2024, 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 +/- $7 million. A one percentage point increase/decrease in the average claim rate reserve factor would change the loss reserve amount by approximately +/- $17 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. 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, 2024 and 2023. Development of reserves for losses and loss adjustment expenses Table 11.1 Nine Months Ended September 30, (In thousands) 2024 2023 Reserve at beginning of period $ 505,379 $ 557,988 Less reinsurance recoverable 33,302 28,240 Net reserve at beginning of period 472,077 529,748 Losses incurred: Losses and LAE incurred in respect of delinquency notices received in: Current year 158,317 137,626 Prior years (1) (181,876) (148,948) Total losses incurred (23,559) (11,322) Losses paid: Losses and LAE paid in respect of delinquency notices received in: Current year 133 153 Prior years 33,138 33,679 Total losses paid 33,271 33,832 Net reserve at end of period 415,247 484,594 Plus reinsurance recoverable 45,327 40,934 Reserve at end of period $ 460,574 $ 525,528 (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 increase in the current year losses incurred in the nine months ended September 30, 2024 as compared to the nine months ended September 30, 2023 is primarily due to an increase in estimated severity on current year delinquencies and an increase in new delinquencies reported. The favorable loss development on previously received delinquencies for the nine months ended September 30, 2024 and September 30, 2023 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 prior year loss reserve development for the nine months ended September 30, 2024 and 2023 is shown in table 11.2 below. Reserve development on previously received delinquencies Table 11.2 Nine Months Ended September 30, (In thousands) 2024 2023 Increase (decrease) in estimated claim rate on primary defaults $ (162,609) $ (142,764) Change in estimates related to severity on primary defaults, pool reserves, LAE reserves, reinsurance, and other (19,267) (6,184) Total prior year loss development (1) $ (181,876) $ (148,948) (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. 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 were $14.4 million and $21.1 million at September 30, 2024 and December 31, 2023, respectively.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2024
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, 2024, we repurchased 17.5 million shares for $373.2 million, which included commissions. In 2023, we repurchased approximately 21.7 million shares of our common stock for $340.6 million, which included commissions. At September 30, 2024, we had remaining authorization to repurchase $651 million remaining under our existing share repurchase program. In October 2024, we repurchased an additional 2.9 million shares totaling $72.4 million under the remaining authorization through December 31, 2026. Cash dividends In the first and second quarters of 2024, we paid quarterly cash dividends of $0.115 per share which totaled $63.3 million. In the third quarter of 2024, we paid quarterly cash dividends of $0.13 per share to shareholders which totaled $34.2 million. On October 24, 2024, the Board of Directors declared a quarterly cash dividend to the holders of the company’s common stock of $0.13 per share payable on November 21, 2024, to shareholders of record on November 7, 2024.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2024
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, 2024 2023 RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs subject to performance conditions (1) 634 $ 19.81 949 $ 14.17 RSUs subject only to service conditions 248 19.81 354 14.17 Non-employee director RSUs 76 19.81 106 14.17 (1) Shares granted are subject to performance conditions under which the target number of shares granted may vest from 0% to 200%.

Statutory Information

Statutory Information	3 Months Ended
	Sep. 30, 2024
Statutory Capital [Abstract]
Statutory Information	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. Our policyholders position was above the required MPP and our risk-to-capital ratio was below the maximum allowed by jurisdictions with State Capital Requirements at September 30, 2024. In 2023, the NAIC adopted a revised Mortgage Guaranty Insurance Model Act. The updated Model Act includes requirements relating to, among other things: (i) capital and minimum capital requirements, and contingency reserves; (ii) restrictions on mortgage insurers’ investments in notes secured by mortgages; (iii) prudent underwriting standards and formal underwriting guidelines; (iv) the establishment of formal, internal “Mortgage Guaranty Quality Control Programs” with respect to in-force business; and (v) reinsurance and prohibitions on captive reinsurance arrangements. It is uncertain when the revised Model Act will be adopted in any jurisdiction. It is unknown whether any changes will be made by state legislatures prior to adoption, and the effect changes, if any, will have on the mortgage guaranty insurance market generally, or on our business. Wisconsin has begun the process to replace current MI regulations with the Model Act, though it is expected that some changes will be made before formal adoption. 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 Statutory Financial Information 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. 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) 2024 2023 Statutory net income $ 356,736 $ 207,996 Statutory policyholders' surplus 655,051 859,083 Contingency loss reserves 5,466,376 5,071,276

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net income	$ 199,969	$ 182,844	$ 578,294	$ 528,445

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
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, 2024
Accounting Standards Update and Change in Accounting Principle [Abstract]
Prospective Accounting Standards	Prospective accounting and reporting developments Relevant new amendments to accounting standards, which are not yet effective or adopted. Segment Reporting—Improvements to Reportable Segment Disclosures: ASU 2023-07 In November 2023, the FASB issued ASU 2023-07. The update expands annual and interim disclosure requirements for reportable segments, primarily through enhanced disclosures about significant segment expenses. The standard will take effect for all public business entities for fiscal periods beginning after December 15, 2023, and interim periods beginning after December 31, 2024. We are currently evaluating the impacts the adoption of this guidance will have on our disclosures. Improvements to Income Tax Disclosures: ASU 2023-09

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Long-term debt	The aggregate carrying value of our 5.25% Senior Notes (“5.25% Notes”) and the par value as of September 30, 2024 and December 31, 2023 is presented in table 3.1 below. Long-term debt obligation, carrying value Table 3.1 (In thousands) September 30, 2024 December 31, 2023 5.25% Notes, due August 2028 (par value: $650 million) $ 644,299 $ 643,196

Reinsurance (Tables)

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2024
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) 2024 2023 2024 2023 Premiums earned: Direct $ 284,435 $ 287,640 $ 851,819 $ 858,310 Assumed 3,625 3,801 10,444 9,635 Ceded: Ceded - quota share reinsurance (1) (27,785) (32,693) (83,143) (90,012) Ceded - excess-of-loss reinsurance (16,935) (17,471) (49,608) (51,830) Total ceded (44,720) (50,164) (132,751) (141,842) Net premiums earned $ 243,340 $ 241,277 $ 729,512 $ 726,103 Losses incurred: Direct $ (5,899) $ 6,627 $ (9,116) $ 2,044 Assumed 30 20 13 (7) Ceded - quota share reinsurance (3,973) (6,724) (14,456) (13,359) Losses incurred, net $ (9,842) $ (77) $ (23,559) $ (11,322) Other Reinsurance Impacts: Profit commission on quota share reinsurance (1) $ 28,620 $ 30,698 $ 80,505 $ 97,218 Ceding commission on quota share reinsurance 11,281 12,678 32,730 37,446 (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 and 2021 QSR 2021 17.5 % 61.9 % December 31, 2032 (2) 2021 QSR and 2022 QSR 2021 12.5 % 57.5 % December 31, 2032 (2) 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 2024 QSR 2024 30.0 % 56.0 % ' December 31, 2035 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. (2) We have elected to terminate our 2021 QSR transaction effective December 31, 2024. 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 and 2021 QSR 2021 December 31, 2024 (3) N/A N/A 2021 QSR and 2022 QSR 2021 December 31, 2024 (3) N/A N/A 2021 QSR and 2022 QSR 2022 December 31, 2024 January 1, 2025 12.5% or 10% 2022 QSR and 2023 QSR 2022 December 31, 2024 January 1, 2025 12.5% or 10% 2022 QSR and 2023 QSR 2023 December 31, 2025 January 1, 2025 12.5% or 10% 2023 QSR 2023 December 31, 2025 January 1, 2025 8% or 7% 2024 QSR 2024 December 31, 2027 December 31, 2027 23% or 15% (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. (3) We have elected to terminate our 2021 QSR transaction effective December 31, 2024, and we expect to incur an early termination fee in the fourth quarter of approximately $8 million.
Schedule of coverages and retention	Table 4.4a, 4.4b, and 4.4c provide a summary of our XOL Transactions as of September 30, 2024 and December 31, 2023. Tables 4.4b and 4.4c exclude the 2024 Traditional XOL which is still in its fill up period. Excess of Loss Reinsurance Table 4.4a Issue Date Policy In force Dates Optional Call Date (1) Legal Maturity 2024 Traditional XOL (2) April 1, 2024 January 1, 2024 - December 31, 2024 January 1, 2030 10 years 2023 Traditional XOL April 1, 2023 January 1, 2023 - December 29, 2023 January 1, 2031 10 years 2022 Traditional XOL April 1, 2022 January 1, 2022 - December 30, 2022 January 1, 2030 10 years Home Re 2023-1, Ltd. October 23, 2023 June 1, 2022 - August 31, 2023 October 25, 2028 10 years Home Re 2022-1, Ltd. April 26, 2022 May 29, 2021 - December 31, 2021 April 25, 2028 12.5 years Home Re 2021-2, Ltd. August 3, 2021 January 1, 2021 - May 28, 2021 July 25, 2028 12.5 years Home Re 2021-1, Ltd. February 2, 2021 August 1, 2020 - December 31, 2020 January 25, 2028 12.5 years Home Re 2019-1, Ltd. May 25, 2019 January 1, 2018 - March 31, 2019 May 25, 2026 10 years (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 2024 Traditional XOL Transaction provides up to $187 million of reinsurance coverage on eligible NIW in 2024. Excess of Loss Reinsurance Table 4.4b Remaining First Layer Retention ($ in thousands) Initial First Layer Retention September 30, 2024 December 31, 2023 2023 Traditional XOL $ 70,578 $ 70,516 $ 70,578 2022 Traditional XOL 82,523 81,653 82,346 Home Re 2023-1, Ltd. 272,961 272,633 272,961 Home Re 2022-1, Ltd. 325,589 323,269 325,001 Home Re 2021-2, Ltd. 190,159 188,803 189,403 Home Re 2021-1, Ltd. 211,159 210,303 210,831 Home Re 2019-1, Ltd. 185,730 182,220 182,722 Table 4.4c Remaining Excess of Loss Reinsurance Coverage (1) ($ in thousands) Initial Excess of Loss Reinsurance Coverage (1) Initial Funding Percentage (2) Funding Percentage at 9/30/2024 (2) September 30, 2024 December 31, 2023 2023 Traditional XOL $ 96,942 N/A N/A $ 92,768 $ 96,942 2022 Traditional XOL 142,642 N/A N/A 129,315 142,642 Home Re 2023-1, Ltd. 330,277 97 % 97 % 316,783 330,277 Home Re 2022-1, Ltd. 473,575 100 % 100 % 330,904 420,731 Home Re 2021-2, Ltd. (3) 398,429 100 % 82 % 145,737 173,960 Home Re 2021-1, Ltd. 398,848 100 % 100 % 110,373 117,982 Home Re 2019-1, Ltd. (3) 315,739 100 % 10 % 21,039 21,039 (1) The initial and remaining excess of loss reinsurance coverage is reduced by the applicable funding percentage. (2) The funding percentage represents the aggregate outstanding note balances divided by the aggregate ending coverage amounts. (3) The funding percentage on the 2021-2 and 2019-1 were reduced from 100% after the tender offers were conducted in the fourth quarter of 2023.
Schedule of total assets of Home Re	Table 4.5 presents the total assets of the Home Re Entities as of September 30, 2024 and December 31, 2023. Home Re total assets Table 4.5 (In thousands) Total VIE Assets Home Re Entity September 30, 2024 December 31, 2023 Home Re 2023-1 Ltd. $ 322,780 $ 330,277 Home Re 2022-1 Ltd. 340,486 427,279 Home Re 2021-2 Ltd. 150,540 174,431 Home Re 2021-1 Ltd. 117,315 118,043 Home Re 2019-1 Ltd. 21,039 21,039

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2024
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) 2024 2023 2024 2023 Basic earnings per share: Net income $ 199,969 $ 182,844 $ 578,294 $ 528,445 Weighted average common shares outstanding - basic 258,596 281,757 264,719 286,184 Basic earnings per share $ 0.77 $ 0.65 $ 2.18 $ 1.85 Diluted earnings per share: Net income $ 199,969 $ 182,844 $ 578,294 $ 528,445 Interest expense, net of tax: (1) 9% Debentures — 276 — 1,025 Diluted income available to common shareholders $ 199,969 $ 183,120 $ 578,294 $ 529,470 Weighted average common shares outstanding - basic 258,596 281,757 264,719 286,184 Effect of dilutive securities: Unvested RSUs 2,237 2,624 2,196 2,239 9% Debentures — 1,219 — 1,501 Weighted average common shares outstanding - diluted 260,833 285,600 266,915 289,924 Diluted earnings per share $ 0.77 $ 0.64 $ 2.17 $ 1.83 (1) Interest expense has been tax effected at a rate of 21%.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2024
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, 2024 and December 31, 2023 are shown in tables 7.1a and 7.1b below. Details of fixed income securities by category as of September 30, 2024 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 $ 257,572 $ 741 $ (4,019) $ 254,294 Obligations of U.S. states and political subdivisions 2,066,711 7,881 (144,890) 1,929,702 Corporate debt securities 2,774,109 40,041 (84,005) 2,730,145 ABS 156,008 3,339 (1,397) 157,950 RMBS 379,184 9,467 (18,216) 370,435 CMBS 270,014 449 (6,927) 263,536 CLOs 236,816 221 (53) 236,984 Foreign government debt 4,487 — (537) 3,950 Commercial paper 17,069 — — 17,069 Total fixed income securities $ 6,161,970 $ 62,139 $ (260,044) $ 5,964,065 Details of fixed income securities by category as of December 31, 2023 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 $ 167,995 $ 51 $ (6,364) $ 161,682 Obligations of U.S. states and political subdivisions 2,092,754 5,159 (189,835) 1,908,078 Corporate debt securities 2,626,401 17,391 (128,211) 2,515,581 ABS 173,256 1,292 (3,275) 171,273 RMBS 347,132 4,297 (20,656) 330,773 CMBS 293,204 5 (15,752) 277,457 CLOs 327,467 37 (1,408) 326,096 Foreign government debt 4,486 — (643) 3,843 Commercial paper 28,327 3 — 28,330 Total fixed income securities $ 6,061,022 $ 28,235 $ (366,144) $ 5,723,113
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, 2024, 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 periodic payments throughout their lives, they are listed in separate categories. Fixed income securities maturity schedule Table 7.2 September 30, 2024 (In thousands) Amortized cost Fair Value Due in one year or less $ 728,611 $ 727,027 Due after one year through five years 1,567,925 1,554,767 Due after five years through ten years 1,816,994 1,744,159 Due after ten years 1,006,418 909,207 5,119,948 4,935,160 ABS 156,008 157,950 RMBS 379,184 370,435 CMBS 270,014 263,536 CLOs 236,816 236,984 Total $ 6,161,970 $ 5,964,065
Cost and fair value of investments in equity securities	The cost and fair value of investments in equity securities at September 30, 2024 and December 31, 2023 are shown in tables 7.3a and 7.3b below. Details of equity security investments as of September 30, 2024 Table 7.3a (In thousands) Cost Fair Value Gains Fair Value Losses Fair Value Equity securities $ 16,115 $ 34 $ (975) $ 15,174 Details of equity security investments as of December 31, 2023 Table 7.3b (In thousands) Cost Fair Value Gains Fair Value Losses Fair Value Equity securities $ 16,025 $ 5 $ (1,259) $ 14,771
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 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) 2024 2023 2024 2023 Fixed income securities Gains on sales $ 28 $ 2,581 $ 508 $ 2,747 Losses on sales (946) (2,814) (7,693) (13,362) Equity securities gains (losses) Changes in fair value 507 (462) 312 (266) Change in embedded derivative on Home Re Transactions 994 (7) (1,336) (2,486) Other Gains (losses) on sales — (4) 17 (4) Market adjustment — 11 (10) (9) Net gains (losses) on investments and other financial instruments $ 583 $ (695) $ (8,202) $ (13,380) Proceeds from sales of fixed income securities $ 14,856 $ 24,434 $ 29,742 $ 293,392
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, 2024 and December 31, 2023, 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 2023 Annual Report on Form 10-K. Unrealized loss aging for securities by type and length of time as of September 30, 2024 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 $ 11,859 $ (42) $ 78,089 $ (3,977) $ 89,948 $ (4,019) Obligations of U.S. states and political subdivisions 94,516 (1,481) 1,235,787 (143,409) 1,330,303 (144,890) Corporate debt securities 240,691 (4,040) 1,152,482 (79,965) 1,393,173 (84,005) ABS 43,761 (852) 26,459 (545) 70,220 (1,397) RMBS 53,033 (4,602) 168,955 (13,614) 221,988 (18,216) CMBS 4,829 (76) 220,234 (6,851) 225,063 (6,927) CLOs 82,196 (53) — — 82,196 (53) Foreign government debt — — 3,950 (537) 3,950 (537) Total $ 530,885 $ (11,146) $ 2,885,956 $ (248,898) $ 3,416,841 $ (260,044) Unrealized loss aging for securities by type and length of time as of December 31, 2023 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 $ 26,550 $ (75) $ 98,359 $ (6,289) $ 124,909 $ (6,364) Obligations of U.S. states and political subdivisions 275,727 (3,622) 1,200,533 (186,213) 1,476,260 (189,835) Corporate debt securities 270,956 (6,060) 1,604,021 (122,151) 1,874,977 (128,211) ABS 41,549 (1,234) 62,611 (2,041) 104,160 (3,275) RMBS 44,867 (872) 176,349 (19,784) 221,216 (20,656) CMBS 35,249 (391) 244,216 (15,361) 279,465 (15,752) CLOs — — 274,729 (1,408) 274,729 (1,408) Foreign government debt — — 3,843 (643) 3,843 (643) Total $ 694,898 $ (12,254) $ 3,664,661 $ (353,890) $ 4,359,559 $ (366,144)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
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, 2024 and December 31, 2023 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 2023 Annual Report on Form 10-K. Assets carried at fair value by hierarchy level as of September 30, 2024 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 $ 254,294 $ 211,991 $ 42,303 Obligations of U.S. states and political subdivisions 1,929,702 — 1,929,702 Corporate debt securities 2,730,145 — 2,730,145 ABS 157,950 — 157,950 RMBS 370,435 — 370,435 CMBS 263,536 — 263,536 CLOs 236,984 — 236,984 Foreign government debt 3,950 — 3,950 Commercial paper 17,069 — 17,069 Total fixed income securities 5,964,065 211,991 5,752,074 Equity securities 15,174 15,174 — Cash equivalents (1) 297,052 271,608 25,444 Total $ 6,276,291 $ 498,773 $ 5,777,518 Assets carried at fair value by hierarchy level as of December 31, 2023 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 $ 161,682 $ 95,828 $ 65,854 Obligations of U.S. states and political subdivisions 1,908,078 — 1,908,078 Corporate debt securities 2,515,581 — 2,515,581 ABS 171,273 — 171,273 RMBS 330,773 — 330,773 CMBS 277,457 — 277,457 CLOs 326,096 — 326,096 Foreign government debt 3,843 — 3,843 Commercial paper 28,330 — 28,330 Total fixed income securities 5,723,113 95,828 5,627,285 Equity securities 14,771 14,771 — Cash equivalents (1) 367,517 367,301 216 Total $ 6,105,401 $ 477,900 $ 5,627,501 (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, 2024 and December 31, 2023. Financial assets and liabilities not measured at fair value Table 8.2 September 30, 2024 December 31, 2023 (In thousands) Carrying Value Fair Value Carrying Value Fair Value Financial assets Other invested assets $ 1,109 $ 1,109 $ 850 $ 850 Financial liabilities 5.25% Senior Notes 644,299 645,983 643,196 634,498

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2024
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, 2024 and 2023 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) 2024 2023 2024 2023 Net unrealized investment gains (losses) arising during the period $ 162,601 $ (95,216) $ 140,005 $ (31,387) Total income tax benefit (expense) (34,146) 19,995 (29,401) 6,591 Net of tax 128,455 (75,221) 110,604 (24,796) Net changes in benefit plan assets and obligations 682 4,067 2,045 11,914 Total income tax benefit (expense) (143) (854) (429) (2,502) Net of tax 539 3,213 1,616 9,412 Total other comprehensive income (loss) $ 163,283 (91,149) 142,050 (19,473) Total income tax benefit (expense) (34,289) 19,141 (29,830) 4,089 Total other comprehensive income (loss), net of tax $ 128,994 $ (72,008) $ 112,220 $ (15,384)
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, 2024 and 2023 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) 2024 2023 2024 2023 Reclassification adjustment for net realized (losses) gains (1) $ (2,368) $ (3,085) $ (14,402) $ (13,020) Income tax benefit (expense) 497 648 3,024 2,734 Net of tax (1,871) (2,437) (11,378) (10,286) Reclassification adjustment related to benefit plan assets and obligations (2) (682) (2,376) (2,045) (12,379) Income tax benefit (expense) 143 499 429 2,600 Net of tax (539) (1,877) (1,616) (9,779) Total reclassifications (3,050) (5,461) (16,447) (25,399) Income tax benefit (expense) 640 1,147 3,453 5,334 Total reclassifications, net of tax $ (2,410) $ (4,314) $ (12,994) $ (20,065) (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, 2024, including amounts reclassified from AOCI, are included in table 9.3 below. Rollforward of AOCI Table 9.3 Nine Months Ended September 30, 2024 (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, 2023, net of tax $ (266,948) $ (49,333) $ (316,281) Other comprehensive income (loss) before reclassifications 99,226 — 99,226 Less: Amounts reclassified from AOCI (11,378) (1,616) (12,994) Balance, September 30, 2024, net of tax $ (156,344) $ (47,717) $ (204,061)

Benefit Plans (Tables)

Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2024
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, 2024 and 2023. 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) 2024 2023 2024 2023 Company service cost $ — $ — $ 417 $ 374 Interest cost 3,247 3,297 376 409 Expected return on plan assets (3,644) (3,426) (2,493) (2,059) Amortization of: Net actuarial losses (gains) 522 529 (382) (38) Prior service cost (credit) 87 87 454 465 Cost of settlements and curtailments — 334 — — Net periodic benefit cost (benefit) $ 212 $ 821 $ (1,628) $ (849) 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) 2024 2023 2024 2023 Company service cost $ — $ — $ 1,251 $ 1,122 Interest cost 9,741 10,278 1,126 1,225 Expected return on plan assets (10,932) (10,432) (7,481) (6,176) Amortization of: Net actuarial losses (gains) 1,568 1,656 (1,142) (113) Prior service cost (credit) 259 259 1,360 1,396 Cost of settlements and curtailments — 9,181 — — Net periodic benefit cost (benefit) $ 636 $ 10,942 $ (4,886) $ (2,546)

Loss Reserves (Tables)

Loss Reserves (Tables)	9 Months Ended
	Sep. 30, 2024
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, 2024 and 2023. Development of reserves for losses and loss adjustment expenses Table 11.1 Nine Months Ended September 30, (In thousands) 2024 2023 Reserve at beginning of period $ 505,379 $ 557,988 Less reinsurance recoverable 33,302 28,240 Net reserve at beginning of period 472,077 529,748 Losses incurred: Losses and LAE incurred in respect of delinquency notices received in: Current year 158,317 137,626 Prior years (1) (181,876) (148,948) Total losses incurred (23,559) (11,322) Losses paid: Losses and LAE paid in respect of delinquency notices received in: Current year 133 153 Prior years 33,138 33,679 Total losses paid 33,271 33,832 Net reserve at end of period 415,247 484,594 Plus reinsurance recoverable 45,327 40,934 Reserve at end of period $ 460,574 $ 525,528 (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, 2024 and 2023 is shown in table 11.2 below. Reserve development on previously received delinquencies Table 11.2 Nine Months Ended September 30, (In thousands) 2024 2023 Increase (decrease) in estimated claim rate on primary defaults $ (162,609) $ (142,764) Change in estimates related to severity on primary defaults, pool reserves, LAE reserves, reinsurance, and other (19,267) (6,184) Total prior year loss development (1) $ (181,876) $ (148,948) (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.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
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, 2024 2023 RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs Granted (in thousands) Weighted Average Share Fair Value RSUs subject to performance conditions (1) 634 $ 19.81 949 $ 14.17 RSUs subject only to service conditions 248 19.81 354 14.17 Non-employee director RSUs 76 19.81 106 14.17 (1) Shares granted are subject to performance conditions under which the target number of shares granted may vest from 0% to 200%.

Statutory Information Statutory

Statutory Information Statutory Information (Tables)	9 Months Ended
	Sep. 30, 2024
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) 2024 2023 Statutory net income $ 356,736 $ 207,996 Statutory policyholders' surplus 655,051 859,083 Contingency loss reserves 5,466,376 5,071,276

Debt - Summary of Debt Obligati

Debt - Summary of Debt Obligations (Details) - Senior Notes - 5.25% Senior Notes Due 2028 - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Long-term debt	$ 644,299	$ 643,196
Stated interest rate	5.25%	5.25%
Debt instrument, face amount	$ 650,000	$ 650,000

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Total interest payments	$ 34,100	$ 35,100

Reinsurance - Summary of Premiu

Reinsurance - Summary of Premiums Earned and Losses Incurred (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Premiums earned:
Direct	$ 284,435	$ 287,640	$ 851,819	$ 858,310
Assumed	3,625	3,801	10,444	9,635
Ceded	(44,720)	(50,164)	(132,751)	(141,842)
Net premiums earned	243,340	241,277	729,512	726,103
Losses incurred:
Direct	(5,899)	6,627	(9,116)	2,044
Assumed	30	20	13	(7)
Losses incurred, net	(9,842)	(77)	(23,559)	(11,322)
Quota Share Reinsurance Transactions
Premiums earned:
Ceded	(27,785)	(32,693)	(83,143)	(90,012)
Losses incurred:
Ceded	(3,973)	(6,724)	(14,456)	(13,359)
Profit commission on quota share reinsurance	28,620	30,698	80,505	97,218
Ceding commission on quota share reinsurance	11,281	12,678	32,730	37,446
Excess of Loss Reinsurance Transactions
Premiums earned:
Ceded	$ (16,935)	$ (17,471)	$ (49,608)	$ (51,830)

Reinsurance - Narrative (Detail

Reinsurance - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves	$ 45,327	$ 33,302	$ 40,934	$ 28,240
Most New Insurance Written In 2025 And 2026
Effects of Reinsurance [Line Items]
Reinsurance, quota share reinsurance agreement, terms, quota share, percent	40%
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%
Reinsurance, quota reinsurance agreement, lifetime loss ratio cap (as a percent)	200%
Threshold for private mortgage insurer eligibility requirements for termination election (less than) (as a percent)	90%
Reinsurance recoverable on loss reserves	$ 45,300	$ 33,300
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%
Reinsurance, quota share reinsurance agreement, terms, quota share, percent	65%
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) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2024	Sep. 30, 2024
2020 QSR and 2021 QSR - 2021 NIW
Effects of Reinsurance [Line Items]
Quota Share %		17.50%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		61.90%
2021 QSR and 2022 QSR - 2021 NIW
Effects of Reinsurance [Line Items]
Quota Share %		12.50%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		57.50%
2021 QSR and 2022 QSR - 2022 NIW
Effects of Reinsurance [Line Items]
Quota Share %		15%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		57.50%
Cede rate, option 1 (as a percent)		12.50%
Cede rate, option 2 (as a percent)		10%
2022 QSR and 2023 QSR - 2022 NIW
Effects of Reinsurance [Line Items]
Quota Share %		15%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		62%
Cede rate, option 1 (as a percent)		12.50%
Cede rate, option 2 (as a percent)		10%
2022 QSR and 2023 QSR - 2023 NIW
Effects of Reinsurance [Line Items]
Quota Share %		15%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		62%
Cede rate, option 1 (as a percent)		12.50%
Cede rate, option 2 (as a percent)		10%
2023 QSR - 2023 NIW
Effects of Reinsurance [Line Items]
Quota Share %		10%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		58.50%
Cede rate, option 1 (as a percent)		8%
Cede rate, option 2 (as a percent)		7%
2024 QSR - 2024 NIW
Effects of Reinsurance [Line Items]
Quota Share %		30%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		56%
Cede rate, option 1 (as a percent)		23%
Cede rate, option 2 (as a percent)		15%
Credit Union QSR Transaction
Effects of Reinsurance [Line Items]
Quota Share %		65%
Annual Loss Ratio to Exhaust Profit Commission (as a percent)		50%
Forecast | Quota Share Reinsurance Transaction, 2021
Effects of Reinsurance [Line Items]
Contingent termination fee	$ 8

Reinsurance - Excess of Loss Re

Reinsurance - Excess of Loss Reinsurance (Details) $ in Thousands									9 Months Ended	12 Months Ended
	Apr. 01, 2024 USD ($)	Oct. 23, 2023 USD ($)	Apr. 01, 2023 USD ($)	Apr. 26, 2022 USD ($)	Apr. 01, 2022 USD ($)	Aug. 03, 2021 USD ($)	Feb. 02, 2021 USD ($)	May 25, 2019 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
2024 Traditional XOL
Effects of Reinsurance [Line Items]
Amortization period excess of loss reinsurance coverage	10 years
Excess of loss reinsurance coverage, initial and remaining	$ 187,000
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			$ 96,942						$ 92,768	$ 96,942
Initial First Layer Retention			$ 70,578
Remaining First Layer Retention									70,516	70,578
2022 Traditional XOL
Effects of Reinsurance [Line Items]
Amortization period excess of loss reinsurance coverage					10 years
Excess of loss reinsurance coverage, initial and remaining					$ 142,642				129,315	142,642
Initial First Layer Retention					$ 82,523
Remaining First Layer Retention									$ 81,653	82,346
Excess of Loss Reinsurance Transactions, Home Re Transactions
Effects of Reinsurance [Line Items]
Percent of reinsurance coverage threshold, option to terminate (as a percent)									10%
Home Re 2023-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes		10 years
Excess of loss reinsurance coverage, initial and remaining		$ 330,277							$ 316,783	330,277
Initial First Layer Retention		$ 272,961
Remaining First Layer Retention									$ 272,633	272,961
Reinsurance Retention Policy, Funding Percentage		0.97							0.97
Home Re 2022-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes				12 years 6 months
Excess of loss reinsurance coverage, initial and remaining				$ 473,575					$ 330,904	420,731
Initial First Layer Retention				$ 325,589
Remaining First Layer Retention									$ 323,269	325,001
Reinsurance Retention Policy, Funding Percentage				1					1
Home Re 2021-2
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes						12 years 6 months
Excess of loss reinsurance coverage, initial and remaining						$ 398,429			$ 145,737	173,960
Initial First Layer Retention						$ 190,159
Remaining First Layer Retention									$ 188,803	189,403
Reinsurance Retention Policy, Funding Percentage						1			0.82
Home Re 2021-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes							12 years 6 months
Excess of loss reinsurance coverage, initial and remaining							$ 398,848		$ 110,373	117,982
Initial First Layer Retention							$ 211,159
Remaining First Layer Retention									$ 210,303	210,831
Reinsurance Retention Policy, Funding Percentage							1		1
Home Re 2019-1
Effects of Reinsurance [Line Items]
Term of mortgage insurance-linked notes								10 years
Excess of loss reinsurance coverage, initial and remaining								$ 315,739	$ 21,039	21,039
Initial First Layer Retention								$ 185,730
Remaining First Layer Retention									$ 182,220	$ 182,722
Reinsurance Retention Policy, Funding Percentage								1	0.10

Reinsurance - Variable Interest

Reinsurance - Variable Interest Entity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Effects of Reinsurance [Line Items]
Total VIE Assets	$ 6,677,784	$ 6,538,380
Home Re 2023-1
Effects of Reinsurance [Line Items]
Total VIE Assets	322,780	330,277
Home Re 2022-1
Effects of Reinsurance [Line Items]
Total VIE Assets	340,486	427,279
Home Re 2021-2
Effects of Reinsurance [Line Items]
Total VIE Assets	150,540	174,431
Home Re 2021-1
Effects of Reinsurance [Line Items]
Total VIE Assets	117,315	118,043
Home Re 2019-1
Effects of Reinsurance [Line Items]
Total VIE Assets	$ 21,039	$ 21,039

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, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Basic earnings per share:
Net income	$ 199,969	$ 182,844	$ 578,294	$ 528,445
Weighted average common shares outstanding - basic (in shares)	258,596	281,757	264,719	286,184
Basic earnings per share (in dollars per share)	$ 0.77	$ 0.65	$ 2.18	$ 1.85
Diluted earnings per share:
Net income	$ 199,969	$ 182,844	$ 578,294	$ 528,445
Dilutive securities	0	276	0	1,025
Diluted income available to common shareholders	$ 199,969	$ 183,120	$ 578,294	$ 529,470
Weighted average common shares outstanding - basic (in shares)	258,596	281,757	264,719	286,184
Effect of dilutive securities:
Unvested RSUs (in shares)	2,237	2,624	2,196	2,239
Dilutive securities (in shares)	0	1,219	0	1,501
Weighted average common shares outstanding - diluted (in shares)	260,833	285,600	266,915	289,924
Diluted earnings per share (in dollars per share)	$ 0.77	$ 0.64	$ 2.17	$ 1.83
Federal statutory income tax rate (in hundredths)	21%	21%	21%	21%
9% Convertible Junior Subordinated Debentures
Effect of dilutive securities:
Stated interest rate		9%		9%

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 6,161,970	$ 6,061,022
Gross Unrealized Gains	62,139	28,235
Gross Unrealized Losses	(260,044)	(366,144)
Fair Value	5,964,065	5,723,113
Assets held by insurance regulatory requirements	12,500	12,200
Assets held in trust for the benefit of contractual counterparties	198,400	156,900
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	257,572	167,995
Gross Unrealized Gains	741	51
Gross Unrealized Losses	(4,019)	(6,364)
Fair Value	254,294	161,682
Obligations of U.S. states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,066,711	2,092,754
Gross Unrealized Gains	7,881	5,159
Gross Unrealized Losses	(144,890)	(189,835)
Fair Value	1,929,702	1,908,078
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,774,109	2,626,401
Gross Unrealized Gains	40,041	17,391
Gross Unrealized Losses	(84,005)	(128,211)
Fair Value	2,730,145	2,515,581
ABS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	156,008	173,256
Gross Unrealized Gains	3,339	1,292
Gross Unrealized Losses	(1,397)	(3,275)
Fair Value	157,950	171,273
RMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	379,184	347,132
Gross Unrealized Gains	9,467	4,297
Gross Unrealized Losses	(18,216)	(20,656)
Fair Value	370,435	330,773
CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	270,014	293,204
Gross Unrealized Gains	449	5
Gross Unrealized Losses	(6,927)	(15,752)
Fair Value	263,536	277,457
CLOs
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	236,816	327,467
Gross Unrealized Gains	221	37
Gross Unrealized Losses	(53)	(1,408)
Fair Value	236,984	326,096
Foreign government debt
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,487	4,486
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(537)	(643)
Fair Value	3,950	3,843
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,069	28,327
Gross Unrealized Gains	0	3
Gross Unrealized Losses	0	0
Fair Value	$ 17,069	$ 28,330

Investments - Amortized Cost an

Investments - Amortized Cost and Fair Values of Debt Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized cost
Due in one year or less	$ 728,611
Due after one year through five years	1,567,925
Due after five years through ten years	1,816,994
Due after ten years	1,006,418
Total debt securities with single maturity date, amortized cost	5,119,948
Amortized Cost	6,161,970	$ 6,061,022
Fair Value
Due in one year or less	727,027
Due after one year through five years	1,554,767
Due after five years through ten years	1,744,159
Due after ten years	909,207
Total debt securities with single maturity date, fair value	4,935,160
Total at end of period	5,964,065	5,723,113
ABS
Amortized cost
Total debt securities without single maturity date, amortized cost	156,008
Amortized Cost	156,008	173,256
Fair Value
Total debt securities without single maturity date, fair value	157,950
Total at end of period	157,950	171,273
RMBS
Amortized cost
Total debt securities without single maturity date, amortized cost	379,184
Amortized Cost	379,184	347,132
Fair Value
Total debt securities without single maturity date, fair value	370,435
Total at end of period	370,435	330,773
CMBS
Amortized cost
Total debt securities without single maturity date, amortized cost	270,014
Amortized Cost	270,014	293,204
Fair Value
Total debt securities without single maturity date, fair value	263,536
Total at end of period	263,536	277,457
CLOs
Amortized cost
Total debt securities without single maturity date, amortized cost	236,816
Amortized Cost	236,816	327,467
Fair Value
Total debt securities without single maturity date, fair value	236,984
Total at end of period	$ 236,984	$ 326,096

Investments - Equity Securities

Investments - Equity Securities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Cost	$ 16,115	$ 16,025
Fair Value Gains	34	5
Fair Value Losses	(975)	(1,259)
Equity securities	$ 15,174	$ 14,771

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, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fixed income securities
Gross realized gains on sales of fixed income securities	$ 28	$ 2,581	$ 508	$ 2,747
Gross realized losses on sales of fixed income securities	(946)	(2,814)	(7,693)	(13,362)
Equity securities gains (losses)
Equity securities, gains (losses), market adjustment	507	(462)	312	(266)
Change in embedded derivative on Home Re Transactions	994	(7)	(1,336)	(2,486)
Other
Other, gains (losses) on sales	0	(4)	17	(4)
Other, market adjustment	0	11	(10)	(9)
Net gains (losses) on investments and other financial instruments	583	(695)	(8,202)	(13,380)
Proceeds from sales of fixed income securities	$ 14,856	$ 24,434	$ 29,742	$ 293,392

Investments - Securities In Unr

Investments - Securities In Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2024 USD ($) security	Dec. 31, 2023 USD ($) security
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	$ 530,885	$ 694,898
12 Months or Greater - Fair Value	2,885,956	3,664,661
Total - Fair Value	3,416,841	4,359,559
Less Than 12 Months - Unrealized Losses	(11,146)	(12,254)
12 Months or Greater - Unrealized Losses	(248,898)	(353,890)
Total - Unrealized Losses	$ (260,044)	$ (366,144)
Number of securities in unrealized loss position (in securities) | security	851	1,021
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	$ 11,859	$ 26,550
12 Months or Greater - Fair Value	78,089	98,359
Total - Fair Value	89,948	124,909
Less Than 12 Months - Unrealized Losses	(42)	(75)
12 Months or Greater - Unrealized Losses	(3,977)	(6,289)
Total - Unrealized Losses	(4,019)	(6,364)
Obligations of U.S. states and political subdivisions
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	94,516	275,727
12 Months or Greater - Fair Value	1,235,787	1,200,533
Total - Fair Value	1,330,303	1,476,260
Less Than 12 Months - Unrealized Losses	(1,481)	(3,622)
12 Months or Greater - Unrealized Losses	(143,409)	(186,213)
Total - Unrealized Losses	(144,890)	(189,835)
Corporate debt securities
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	240,691	270,956
12 Months or Greater - Fair Value	1,152,482	1,604,021
Total - Fair Value	1,393,173	1,874,977
Less Than 12 Months - Unrealized Losses	(4,040)	(6,060)
12 Months or Greater - Unrealized Losses	(79,965)	(122,151)
Total - Unrealized Losses	(84,005)	(128,211)
ABS
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	43,761	41,549
12 Months or Greater - Fair Value	26,459	62,611
Total - Fair Value	70,220	104,160
Less Than 12 Months - Unrealized Losses	(852)	(1,234)
12 Months or Greater - Unrealized Losses	(545)	(2,041)
Total - Unrealized Losses	(1,397)	(3,275)
RMBS
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	53,033	44,867
12 Months or Greater - Fair Value	168,955	176,349
Total - Fair Value	221,988	221,216
Less Than 12 Months - Unrealized Losses	(4,602)	(872)
12 Months or Greater - Unrealized Losses	(13,614)	(19,784)
Total - Unrealized Losses	(18,216)	(20,656)
CMBS
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	4,829	35,249
12 Months or Greater - Fair Value	220,234	244,216
Total - Fair Value	225,063	279,465
Less Than 12 Months - Unrealized Losses	(76)	(391)
12 Months or Greater - Unrealized Losses	(6,851)	(15,361)
Total - Unrealized Losses	(6,927)	(15,752)
CLOs
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	82,196	0
12 Months or Greater - Fair Value	0	274,729
Total - Fair Value	82,196	274,729
Less Than 12 Months - Unrealized Losses	(53)	0
12 Months or Greater - Unrealized Losses	0	(1,408)
Total - Unrealized Losses	(53)	(1,408)
Foreign government debt
Schedule of Investments [Line Items]
Less Than 12 Months - Fair Value	0	0
12 Months or Greater - Fair Value	3,950	3,843
Total - Fair Value	3,950	3,843
Less Than 12 Months - Unrealized Losses	0	0
12 Months or Greater - Unrealized Losses	(537)	(643)
Total - Unrealized Losses	$ (537)	$ (643)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 5,964,065		$ 5,723,113
Equity securities	15,174		14,771
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,964,065		5,723,113
Equity securities	15,174		14,771
Cash equivalents	297,052		367,517
Total assets	6,276,291		6,105,401
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	211,991		95,828
Equity securities	15,174		14,771
Cash equivalents	271,608		367,301
Total assets	498,773		477,900
Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,752,074		5,627,285
Equity securities	0		0
Cash equivalents	25,444		216
Total assets	5,777,518		5,627,501
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	1,000		2,400
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	3,700	$ 100
Sales of real estate assets acquired	600	$ 1,600
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	254,294		161,682
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	254,294		161,682
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	211,991		95,828
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	42,303		65,854
Obligations of U.S. states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1,929,702		1,908,078
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	1,929,702		1,908,078
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	1,929,702		1,908,078
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,730,145		2,515,581
Corporate debt securities | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,730,145		2,515,581
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	2,730,145		2,515,581
ABS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	157,950		171,273
ABS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	157,950		171,273
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	157,950		171,273
RMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	370,435		330,773
RMBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	370,435		330,773
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	370,435		330,773
CMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	263,536		277,457
CMBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	263,536		277,457
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	263,536		277,457
CLOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	236,984		326,096
CLOs | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	236,984		326,096
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	236,984		326,096
Foreign government debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	3,950		3,843
Foreign government debt | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	3,950		3,843
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	3,950		3,843
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	17,069		28,330
Commercial paper | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	17,069		28,330
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	$ 17,069		$ 28,330

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	$ 1,109	$ 850
Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	$ 1,109	$ 850
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%	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	$ 644,299	$ 643,196
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	$ 645,983	$ 634,498

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total other comprehensive income (loss)	$ 163,283	$ (91,149)	$ 142,050	$ (19,473)
Income tax benefit (expense)	(34,289)	19,141	(29,830)	4,089
Other comprehensive income (loss), net of tax	128,994	(72,008)	112,220	(15,384)
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	254,296	234,396	734,001	672,382
Income tax benefit (expense)	(54,327)	(51,552)	(155,707)	(143,937)
Total reclassifications, net of tax	199,969	182,844	578,294	528,445
Reclassification from Accumulated Other Comprehensive Income
Amounts Reclassified From Accumulated Other Comprehensive Income [Abstract]
Total reclassifications before tax	(3,050)	(5,461)	(16,447)	(25,399)
Income tax benefit (expense)	640	1,147	3,453	5,334
Total reclassifications, net of tax	(2,410)	(4,314)	(12,994)	(20,065)
Accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss), net of tax	128,994	(72,008)	112,220	(15,384)
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)	162,601	(95,216)	140,005	(31,387)
Income tax benefit (expense)	(34,146)	19,995	(29,401)	6,591
Other comprehensive income (loss), net of tax	128,455	(75,221)	110,604	(24,796)
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	(2,368)	(3,085)	(14,402)	(13,020)
Income tax benefit (expense)	497	648	3,024	2,734
Total reclassifications, net of tax	(1,871)	(2,437)	(11,378)	(10,286)
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)	682	4,067	2,045	11,914
Income tax benefit (expense)	(143)	(854)	(429)	(2,502)
Other comprehensive income (loss), net of tax	539	3,213	1,616	9,412
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	(682)	(2,376)	(2,045)	(12,379)
Income tax benefit (expense)	143	499	429	2,600
Total reclassifications, net of tax	$ (539)	$ (1,877)	$ (1,616)	$ (9,779)

Other Comprehensive Income - Ro

Other Comprehensive Income - Rollforward of AOCI (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	$ 5,072,017
Other comprehensive income (loss) before reclassifications	99,226
Less: Amounts reclassified from AOCI	(12,994)
Balance, end of period	5,294,076
Accumulated other comprehensive income (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(316,281)
Balance, end of period	(204,061)
Net unrealized gains and (losses) on available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(266,948)
Other comprehensive income (loss) before reclassifications	99,226
Less: Amounts reclassified from AOCI	(11,378)
Balance, end of period	(156,344)
Net benefit plan assets and (obligations) recognized in shareholders' equity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(49,333)
Other comprehensive income (loss) before reclassifications	0
Less: Amounts reclassified from AOCI	(1,616)
Balance, end of period	$ (47,717)

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pension and Supplemental Executive Retirement Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	$ 0		$ 0	$ 0	$ 0
Interest cost	3,247		3,297	9,741	10,278
Expected return on plan assets	(3,644)		(3,426)	(10,932)	(10,432)
Net actuarial losses (gains)	522		529	1,568	1,656
Prior service cost (credit)	87		87	259	259
Cost of settlements and curtailments	0		334	0	9,181
Net periodic benefit cost (benefit)	212		821	636	10,942
Other Postretirement Benefit Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	417		374	1,251	1,122
Interest cost	376		409	1,126	1,225
Expected return on plan assets	(2,493)		(2,059)	(7,481)	(6,176)
Net actuarial losses (gains)	(382)		(38)	(1,142)	(113)
Prior service cost (credit)	454		465	1,360	1,396
Cost of settlements and curtailments	0		0	0	0
Net periodic benefit cost (benefit)	$ (1,628)		$ (849)	$ (4,886)	$ (2,546)
Pension Plan
Components of Net Periodic Benefit Cost [Abstract]
Company contribution to qualified pension plan		$ 23,000

Loss Reserves (Details)

Loss Reserves (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves	$ (44,805)	$ (32,460)
Losses incurred related to prior year notices	(181,876)	(148,948)
Premium refund liability, expected claim payments	14,400		$ 21,100
$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	7,000
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	17,000
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	(162,609)	(142,764)
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	$ (19,267)	$ (6,184)

Loss Reserves - Reconciliation

Loss Reserves - Reconciliation of Beginning and Ending Balances (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Loss Reserve [Roll Forward]
Reserve at beginning of period	$ 505,379	$ 557,988
Less reinsurance recoverable	33,302	28,240
Net reserve at beginning of period	472,077	529,748
Losses and LAE incurred in respect of delinquency notices received in:
Current year	158,317	137,626
Prior years	(181,876)	(148,948)
Total losses incurred	(23,559)	(11,322)
Losses and LAE paid in respect of delinquency notices received in:
Current year	133	153
Prior years	33,138	33,679
Total losses paid	33,271	33,832
Net reserve at end of period	415,247	484,594
Plus reinsurance recoverable	45,327	40,934
Reserve at end of period	$ 460,574	$ 525,528

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Oct. 24, 2024	Oct. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Shares repurchased in period (in shares)					17.5	21.7
Repurchase of common stock amount, including commissions					$ 373.2	$ 340.6
Remaining authorized repurchase amount			$ 651		$ 651
Quarterly cash dividend paid (per share)			$ 0.13	$ 0.115
Cash dividends			$ 34.2	$ 63.3
Subsequent Event
Class of Stock [Line Items]
Shares repurchased in period (in shares)		2.9
Repurchase of common stock amount, including commissions		$ 72.4
Quarterly cash dividend declared (per share)	$ 0.13

Share-Based Compensation (Detai

Share-Based Compensation (Details) - $ / shares shares in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
RSUs subject to performance conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	634	949
Weighted Average Share Fair Value (in dollars per share)	$ 19.81	$ 14.17
RSUs subject only to service conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	248	354
Weighted Average Share Fair Value (in dollars per share)	$ 19.81	$ 14.17
Non-employee director RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	76	106
Weighted Average Share Fair Value (in dollars per share)	$ 19.81	$ 14.17
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	1 year
Minimum | RSUs subject to performance conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of shares that may vest (as a percent)	0%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Maximum | RSUs subject to performance conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of shares that may vest (as a percent)	200%

Statutory Information - Narrati

Statutory Information - Narrative (Details) $ in Millions	1 Months Ended		9 Months Ended
	Oct. 31, 2024 USD ($)	Apr. 30, 2024 USD ($)	Sep. 30, 2024 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]
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		$ 350
Mortgage Guaranty Insurance Corporation | Subsequent Event
Statutory capital requirements [Abstract]
Dividend paid to MGIC Investment Corporation	$ 400

Statutory Information - Summary

Statutory Information - Summary of Amounts Disclosed Under Statutory Accounting Practices (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Statutory Capital [Abstract]
Statutory net income	$ 356,736	$ 207,996
Statutory policyholders' surplus	655,051	859,083
Contingency loss reserves	$ 5,466,376	$ 5,071,276