Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
Fixed-maturities available for sale—at fair value, net of allowance for credit losses of $0 and $948 (amortized cost of $5,367,729 and $5,393,623)	$ 5,517,078	$ 5,723,340
Trading securities—at fair value (amortized cost of $234,382 and $260,773)	256,546	290,885
Equity securities—at fair value (cost of $176,229 and $145,501)	184,245	151,240
Short-term investments—at fair value (includes $48,652 and $15,587 of reinvested cash collateral held under securities lending agreements)	551,508	618,004
Other invested assets—at fair value	4,165	4,973
Total investments	6,513,542	6,788,442
Cash	151,145	87,915
Restricted cash	1,475	6,231
Accrued investment income	32,812	34,047
Accounts and notes receivable	124,016	121,294
Reinsurance recoverables (includes $51 and $32 for paid losses)	67,896	73,202
Deferred policy acquisition costs	16,317	18,305
Property and equipment, net (Note 2)	75,086	80,457
Goodwill and other acquired intangible assets, net (Note 7)	19,593	23,043
Other assets (Note 9)	837,303	715,085
Total assets	7,839,185	7,948,021
Liabilities
Unearned premiums	329,090	448,791
Reserve for losses and LAE (Note 11)	828,642	848,413
Senior notes (Note 12)	1,409,473	1,405,674
FHLB advances (Note 12)	150,983	176,483
Reinsurance funds withheld	228,078	278,555
Net deferred tax liability (Note 10)	337,509	213,897
Other liabilities	296,614	291,855
Total liabilities	3,580,389	3,663,668
Commitments and Contingencies (Note 13)
Stockholders’ equity
Common stock: par value $0.001 per share; 485,000 shares authorized at December 31, 2021 and 2020; 194,408 and 210,130 shares issued at December 31, 2021 and 2020, respectively; 175,421 and 191,606 shares outstanding at December 31, 2021 and 2020, respectively	194	210
Treasury stock, at cost: 18,987 and 18,524 shares at December 31, 2021 and 2020, respectively	(920,798)	(910,115)
Additional paid-in capital	1,878,372	2,245,897
Retained earnings	3,180,935	2,684,636
Accumulated other comprehensive income (loss) (Note 15)	120,093	263,725
Total stockholders’ equity	4,258,796	4,284,353
Total liabilities and stockholders’ equity	$ 7,839,185	$ 7,948,021