Condensed Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net premiums earned	$ 269,152	$ 228,595
Net investment income	17,883	16,424
Net realized gains	5,588	14,150
Net unrealized gains (losses) on equity securities	(27,810)	28,162
Consolidated revenue	264,813	287,331
Losses and settlement expenses	105,524	104,892
Policy acquisition costs	85,287	74,990
Insurance operating expenses	18,863	18,796
Interest expense on debt	2,010	1,901
General corporate expenses	3,363	3,342
Total expenses	215,047	203,921
Equity in earnings of unconsolidated investees	8,759	6,424
Earnings before income taxes	58,525	89,834
Income tax expense	10,602	16,822
Net earnings	47,923	73,012
Other comprehensive earnings (loss), net of tax	(115,581)	(44,747)
Comprehensive earnings (loss)	$ (67,658)	$ 28,265
Basic net earnings per share	$ 1.06	$ 1.62
Diluted net earnings per share	$ 1.05	$ 1.60
Weighted average number of common shares outstanding:
Basic	45,306	45,178
Diluted	45,714	45,674