Condensed Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Net premiums earned	$ 307,723	$ 269,152
Net investment income	27,084	17,883
Net realized gains	14,620	5,588
Net unrealized gains (losses) on equity securities	15,496	(27,810)
Consolidated revenue	364,923	264,813
Losses and settlement expenses	114,488	105,524
Policy acquisition costs	101,444	85,287
Insurance operating expenses	23,901	18,863
Interest expense on debt	2,008	2,010
General corporate expenses	4,214	3,363
Total expenses	246,055	215,047
Equity in earnings of unconsolidated investees	3,923	8,759
Earnings (loss) before income taxes	122,791	58,525
Income tax expense	23,980	10,602
Net earnings (loss)	98,811	47,923
Other comprehensive earnings (loss), net of tax	37,707	(115,581)
Comprehensive earnings	$ 136,518	$ (67,658)
Basic net earnings per share	$ 2.17	$ 1.06
Diluted net earnings per share	$ 2.15	$ 1.05
Weighted average number of common shares outstanding:
Basic	45,530	45,306
Diluted	46,035	45,714