Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Investments (Notes 5 and 6)
Fixed-maturities available for sale—at fair value (amortized cost of $5,685,122 and $5,587,261)	$ 5,155,897	$ 5,017,711
Trading securities—at fair value (amortized cost of $111,226 and $122,472)	105,929	115,665
Equity securities—at fair value (cost of $141,929 and $162,899)	133,106	148,965
Mortgage loans held for sale—at fair value	59,252	3,549
Other invested assets—at fair value	5,762	5,511
Short-term investments—at fair value (includes $72,023 and $99,735 of reinvested cash collateral held under securities lending agreements)	435,925	402,090
Total investments	5,895,871	5,693,491
Cash	61,142	56,183
Restricted cash	1,317	377
Accrued investment income	42,650	40,093
Accounts and notes receivable	138,432	119,834
Reinsurance recoverables (includes $18 and $18 for paid losses)	22,979	25,633
Deferred policy acquisition costs	19,272	18,460
Property and equipment, net	73,885	70,981
Goodwill and other acquired intangible assets, net (Note 7)	12,543	15,285
Prepaid federal income taxes (Note 10)	663,320	596,368
Other assets (Note 9)	375,132	427,024
Total assets	7,306,543	7,063,729
Liabilities
Unearned premiums	246,666	271,479
Reserve for losses and LAE (Note 11)	379,434	426,843
Senior notes (Note 12)	1,415,610	1,413,504
Secured borrowings (Note 12)	178,762	155,822
Reinsurance funds withheld	154,354	152,067
Net deferred tax liability	479,754	391,083
Other liabilities	281,127	333,604
Total liabilities	3,135,707	3,144,402
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock ($0.001 par value; 485,000 shares authorized; 2023: 177,386 and 157,350 shares issued and outstanding, respectively; 2022: 176,509 and 157,056 shares issued and outstanding, respectively)	177	176
Treasury stock, at cost (2023: 20,036 shares; 2022: 19,453 shares)	(945,032)	(930,643)
Additional paid-in capital	1,522,895	1,519,641
Retained earnings	4,016,482	3,786,952
Accumulated other comprehensive income (loss) (Note 15)	(423,686)	(456,799)
Total stockholders’ equity	4,170,836	3,919,327
Total liabilities and stockholders’ equity	$ 7,306,543	$ 7,063,729