Condensed Consolidated Statements of Earnings and Comprehensive Earnings (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net premiums earned	$ 146,552	$ 128,334	$ 393,429	$ 366,356
Net investment income	15,954	16,762	47,437	50,127
Net realized investment gains (losses)	80	4,527	14,602	15,281
Other-than-temporary impairment (OTTI) losses on investments	(257)		(257)
Consolidated revenue	162,329	149,623	455,211	431,764
Losses and settlement expenses	64,802	55,823	142,036	155,152
Policy acquisition costs	46,712	40,624	129,813	118,804
Insurance operating expenses	10,302	10,161	32,047	27,158
Interest expense on debt	1,513	1,512	4,537	4,537
General corporate expenses	1,594	2,148	5,563	5,406
Total expenses	124,923	110,268	313,996	311,057
Equity in earnings of unconsolidated investee	713	1,648	7,215	7,327
Earnings before income taxes	38,119	41,003	148,430	128,034
Income tax expense	12,062	13,038	48,531	40,854
Net earnings	26,057	27,965	99,899	87,180
Other comprehensive earnings (loss), net of tax	(14,331)	30,476	(6,323)	27,986
Comprehensive earnings	$ 11,726	$ 58,441	$ 93,576	$ 115,166
Basic:
Basic net earnings per share (in dollars per share)	$ 1.24	$ 1.34	$ 4.74	$ 4.14
Basic comprehensive earnings per share (in dollars per share)	$ 0.56	$ 2.79	$ 4.44	$ 5.47
Diluted:
Diluted net earnings per share (in dollars per share)	$ 1.22	$ 1.33	$ 4.68	$ 4.11
Diluted comprehensive earnings per share (in dollars per share)	$ 0.55	$ 2.77	$ 4.39	$ 5.42
Weighted average number of common shares outstanding
Basic (in shares)	21,089	20,931	21,063	21,043
Diluted (in shares)	21,335	21,090	21,324	21,233
Cash dividends declared per common share (in dollars per share)	$ 0.30	$ 0.29	$ 0.89	$ 0.86