Condensed Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Net premiums earned	$ 318,409	$ 291,468	$ 948,412	$ 843,430
Net investment income	31,963	21,270	87,835	57,625
Net realized gains	6,558	573,170	26,758	591,562
Net unrealized gains (losses) on equity securities	(25,236)	(26,414)	15,474	(155,218)
Consolidated revenue	331,694	859,494	1,078,479	1,337,399
Losses and settlement expenses	189,558	165,089	457,989	388,527
Policy acquisition costs	103,013	96,977	307,083	271,879
Insurance operating expenses	21,591	20,606	70,002	58,794
Interest expense on debt	1,873	2,013	5,928	6,034
General corporate expenses	2,372	2,755	10,805	8,553
Total expenses	318,407	287,440	851,807	733,787
Equity in earnings (loss) of unconsolidated investees	1,732	(17,352)	7,169	3,061
Earnings before income taxes	15,019	554,702	233,841	606,673
Income tax expense	1,483	114,809	43,842	121,096
Net earnings	13,536	439,893	189,999	485,577
Other comprehensive earnings (loss), net of tax	(56,834)	(81,248)	(38,848)	(294,392)
Comprehensive earnings (loss)	$ (43,298)	$ 358,645	$ 151,151	$ 191,185
Basic net earnings per share	$ 0.30	$ 9.69	$ 4.17	$ 10.71
Diluted net earnings per share	$ 0.29	$ 9.61	$ 4.12	$ 10.61
Weighted average number of common shares outstanding:
Basic	45,622	45,379	45,581	45,347
Diluted	46,065	45,775	46,067	45,775