Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Investments (Notes 5 and 6)
Fixed-maturities available for sale—at fair value (amortized cost of $5,657,808 and $5,599,111)	$ 5,209,025	$ 5,188,228
Trading securities—at fair value (amortized cost of $109,275 and $110,484)	103,256	106,423
Equity securities—at fair value (cost of $159,937 and $92,124)	155,405	89,057
Mortgage loans held for sale—at fair value (Note 7)	147,034	32,755
Other invested assets—at fair value	8,849	8,625
Short-term investments—at fair value (includes $89,532 and $149,364 of reinvested cash collateral held under securities lending agreements)	703,545	660,566
Total investments	6,327,114	6,085,654
Cash	26,993	18,999
Restricted cash	1,832	1,066
Accrued investment income	46,334	45,783
Accounts and notes receivable	130,095	123,857
Reinsurance recoverables (includes $164 and $59 for paid losses)	28,151	25,909
Deferred policy acquisition costs	18,561	18,718
Property and equipment, net	60,521	63,822
Prepaid federal income taxes (Note 10)	750,320	750,320
Other assets (Note 9)	369,944	459,805
Total assets	7,759,865	7,593,933
Liabilities
Unearned premiums	215,124	225,396
Reserve for losses and LAE (Note 11)	361,833	370,148
Senior notes (Note 12)	1,512,860	1,417,781
Secured borrowings (Note 12)	207,601	119,476
Reinsurance funds withheld	133,460	130,564
Net deferred tax liability	626,353	589,564
Other liabilities	262,902	343,199
Total liabilities	3,320,133	3,196,128
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock ($0.001 par value; 485,000 shares authorized; 2024: 171,588 and 151,509 shares issued and outstanding, respectively; 2023: 173,247 and 153,179 shares issued and outstanding, respectively)	171	173
Treasury stock, at cost (2024: 20,079 shares; 2023: 20,068 shares)	(946,202)	(945,870)
Additional paid-in capital	1,390,436	1,430,594
Retained earnings	4,357,823	4,243,759
Accumulated other comprehensive income (loss) (Note 15)	(362,496)	(330,851)
Total stockholders’ equity	4,439,732	4,397,805
Total liabilities and stockholders’ equity	$ 7,759,865	$ 7,593,933