CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 762,994	$ 712,949	$ 865,349
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and other amortization	18,436	35,230	54,252
Deferred tax expense (benefit)	2,432	1,065	(4,367)
Equity compensation	31,324	31,607	24,771
Loss on debt extinguishment	0	0	40,199
Net (gains) losses on investments and other financial instruments	9,846	14,141	7,463
Change in certain assets and liabilities:
Accrued investment income	(2,290)	(3,596)	(3,276)
Reinsurance recoverable on loss reserves	(13,979)	(5,062)	38,665
Reinsurance recoverable on paid losses	5,699	8,185	18,194
Premiums receivable	963	(499)	(1,460)
Deferred insurance policy acquisition costs	2,897	4,471	2,609
Loss reserves	(42,717)	(52,609)	(325,534)
Unearned premiums	(37,419)	(37,510)	(46,401)
Return premium accrual	(8,600)	(4,400)	(11,800)
Current income taxes	16,274	(4,143)	(8,549)
Other, net	(20,828)	13,133	(103)
Net cash provided by operating activities	725,032	712,962	650,012
Cash flows from investing activities:
Purchases of investments	(1,555,624)	(1,469,540)	(674,406)
Proceeds from sales of investments	45,087	376,598	399,661
Proceeds from maturity of fixed income securities	1,369,706	913,415	688,484
Proceeds from sale of property and equipment	0	2,336	0
Additions to property and equipment	(1,174)	(1,999)	(3,254)
Net cash (used in) provided by investing activities	(142,005)	(179,190)	410,485
Cash flows from financing activities:
Conversion / purchase of convertible junior subordinated debentures	0	(28,637)	(89,118)
Redemption of 5.75% senior notes	0	0	(242,296)
Repayment of FHLB advance	0	0	(155,000)
Cash portion of loss on debt extinguishment	0	0	(39,514)
Repurchase of common stock	(569,478)	(337,182)	(385,573)
Dividends paid	(130,500)	(122,965)	(110,947)
Payment of withholding taxes related to share-based compensation net share settlement	(19,066)	(7,257)	(10,094)
Net cash used in financing activities	(719,044)	(496,041)	(1,032,542)
Net (decrease) increase in cash and cash equivalents and restricted cash and cash equivalents	(136,017)	37,731	27,955
Cash and cash equivalents and restricted cash and cash equivalents at beginning of year	370,644	332,913	304,958
Cash and cash equivalents and restricted cash and cash equivalents at end of year	$ 234,627	$ 370,644	$ 332,913