Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investments
Fixed-maturities available for sale—at fair value (amortized cost of $5,599,111 and $5,587,261)	$ 5,188,228	$ 5,017,711
Trading securities—at fair value (amortized cost of $110,484 and $122,472)	106,423	115,665
Equity securities—at fair value (cost of $92,124 and $162,899)	89,057	148,965
Mortgage loans held for sale—at fair value	32,755	3,549
Other invested assets—at fair value	8,625	5,511
Short-term investments—at fair value (includes $149,364 and $99,735 of reinvested cash collateral held under securities lending agreements)	660,566	402,090
Total investments	6,085,654	5,693,491
Cash	18,999	56,183
Restricted cash	1,066	377
Accrued investment income	45,783	40,093
Accounts and notes receivable	123,857	119,834
Reinsurance recoverable (includes $59 and $18 for paid losses)	25,909	25,633
Deferred policy acquisition costs	18,718	18,460
Property and equipment, net (Note 2)	63,822	70,981
Goodwill and other acquired intangible assets, net (Note 2)	0	15,285
Prepaid federal income taxes (Note 10)	750,320	596,368
Other assets (Note 9)	459,805	427,024
Total assets	7,593,933	7,063,729
Liabilities
Unearned premiums	225,396	271,479
Reserve for losses and LAE (Note 11)	370,148	426,843
Senior notes (Note 12)	1,417,781	1,413,504
Secured borrowings (Note 12)	119,476	155,822
Reinsurance funds withheld	130,564	152,067
Net deferred tax liability (Note 10)	589,564	391,083
Other liabilities	343,199	333,604
Total liabilities	3,196,128	3,144,402
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock ($0.001 par value; 485,000 shares authorized; 2023: 173,247 and 153,179 shares issued and outstanding, respectively; 2022: 176,509 and 157,056 shares issued and outstanding, respectively)	173	176
Treasury stock, at cost (2023: 20,068 shares; 2022: 19,453 shares)	(945,870)	(930,643)
Additional paid-in capital	1,430,594	1,519,641
Retained earnings	4,243,759	3,786,952
Accumulated other comprehensive income (loss) (Note 15)	(330,851)	(456,799)
Total stockholders’ equity	4,397,805	3,919,327
Total liabilities and stockholders’ equity	$ 7,593,933	$ 7,063,729