Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net income	$ 600,671	$ 393,626	$ 672,309
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Net (gains) losses on investments and other financial instruments	(15,603)	(60,277)	(51,719)
Loss on extinguishment of debt	0	0	22,738
Impairment of goodwill	0	0	4,828
Amortization and impairment of other acquired intangible assets	3,450	5,144	22,288
Depreciation, other amortization, and other impairments, net	72,020	66,585	50,439
Deferred income tax provision	161,793	102,079	157,162
Change in:
Accrued investment income	1,235	(1,714)	2,545
Accounts and notes receivable	(2,722)	(29,280)	(25,504)
Reinsurance recoverables	5,306	(56,226)	(2,574)
Deferred policy acquisition costs	1,988	2,454	(3,448)
Other assets	(78,163)	38,680	(77,181)
Unearned premiums	(119,701)	(178,031)	(112,535)
Reserve for losses and LAE	(19,771)	443,648	3,404
Reinsurance funds withheld	(50,477)	(13,274)	(29,383)
Other liabilities	(2,914)	(54,980)	61,062
Net cash provided by (used in) operating activities	557,112	658,434	694,431
Cash flows from investing activities
Fixed-maturities available for sale	735,340	963,589	986,647
Trading securities	7,952	11,602	130,537
Equity securities	36,748	90,450	69,779
Fixed-maturities available for sale	1,225,626	645,068	464,777
Trading securities	16,668	22,913	37,684
Fixed-maturities available for sale	(1,980,155)	(2,449,762)	(1,913,703)
Equity securities	(105,649)	(85,014)	(57,422)
Short-term investments, net	68,083	(82,925)	8,017
Other assets and other invested assets, net	6,126	1,434	(739)
Proceeds from sale of subsidiary, net of cash sold	0	16,481	0
Purchases of property and equipment	(12,601)	(17,016)	(27,626)
Net cash provided by (used in) investing activities	(1,862)	(883,180)	(302,049)
Cash flows from financing activities
Dividends and dividend equivalents paid	(103,298)	(97,458)	(2,061)
Issuance of common stock	1,382	1,553	2,416
Repurchases of common stock	(399,100)	(226,305)	(300,201)
Issuance of senior notes, net	0	515,567	442,439
Repayments and repurchases of senior notes	0	0	(610,763)
Credit facility commitment fees paid	(3,325)	(2,292)	(989)
Change in secured borrowings, net (with terms three months or less)	13,565	(37,475)	13,862
Proceeds from secured borrowings (with terms greater than three months)	42,000	207,034	115,275
Repayments of secured borrowings (with terms greater than three months)	(48,000)	(137,927)	(62,932)
Repayments of other borrowings	0	(79)	(152)
Net cash provided by (used in) financing activities	(496,776)	222,618	(403,106)
Effect of exchange rate changes on cash and restricted cash	0	0	(4)
Increase (decrease) in cash and restricted cash	58,474	(2,128)	(10,728)
Cash and restricted cash, beginning of period	94,146	96,274	107,002
Cash and restricted cash, end of period	152,620	94,146	96,274
Supplemental disclosures of cash flow information
Income taxes paid (Note 10)	143,973	81,404	71,469
Interest paid	$ 78,704	$ 60,564	$ 45,762