Condensed Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
Net premiums earned	$ 407,695	$ 389,489	$ 1,207,944	$ 1,129,230
Net investment income	41,270	36,694	117,414	103,502
Net realized gains (losses)	18,318	5,420	48,234	11,222
Net unrealized gains on equity securities	41,981	38,392	43,163	87,314
Consolidated revenue	509,264	469,995	1,416,755	1,331,268
Losses and settlement expenses	187,998	202,118	549,814	513,741
Policy acquisition costs	128,937	117,811	378,126	342,186
Insurance operating expenses	30,215	28,868	86,683	84,892
Interest expense on debt	1,364	1,617	4,049	4,839
General corporate expenses	5,045	3,994	12,747	13,144
Total expenses	353,559	354,408	1,031,419	958,802
Equity in earnings of unconsolidated investees	1,540	1,238	7,055	7,653
Earnings before income taxes	157,245	116,825	392,391	380,119
Income tax expense	32,635	21,798	80,231	75,200
Net earnings	124,610	95,027	312,160	304,919
Other comprehensive earnings (loss), net of tax	27,674	80,293	76,405	59,779
Comprehensive earnings	$ 152,284	$ 175,320	$ 388,565	$ 364,698
Basic net earnings per share	$ 1.36	$ 1.04	$ 3.4	$ 3.33
Diluted net earnings per share	$ 1.35	$ 1.03	$ 3.38	$ 3.3
Weighted average number of common shares outstanding:
Basic	91,849	91,559	91,816	91,467
Diluted	92,310	92,441	92,460	92,370