Condensed Consolidated Statements of Earnings and Comprehensive Earnings (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net premiums earned	$ 130,826	$ 121,758	$ 246,877	$ 238,022
Net investment income	15,180	16,765	31,483	33,365
Net realized investment gains	10,050	4,291	14,522	10,754
Other-than-temporary impairment (OTTI) losses on investments	0		0
Consolidated revenue	156,056	142,814	292,882	282,141
Losses and settlement expenses	30,363	45,072	77,234	99,329
Policy acquisition costs	42,568	37,715	83,101	78,180
Insurance operating expenses	12,130	8,170	21,745	16,997
Interest expense on debt	1,512	1,513	3,024	3,025
General corporate expenses	1,964	1,541	3,969	3,258
Total expenses	88,537	94,011	189,073	200,789
Equity in earnings of unconsolidated investee	3,886	3,426	6,502	5,679
Earnings before income taxes	71,405	52,229	110,311	87,031
Income tax expense	24,024	17,235	36,469	27,816
Net earnings	47,381	34,994	73,842	59,215
Other comprehensive earnings (loss), net of tax	2,760	(11,765)	8,008	(2,490)
Comprehensive earnings	$ 50,141	$ 23,229	$ 81,850	$ 56,725
Basic:
Basic net earnings per share (in dollars per share)	$ 2.25	$ 1.66	$ 3.51	$ 2.81
Basic comprehensive earnings per share (in dollars per share)	$ 2.38	$ 1.10	$ 3.89	$ 2.69
Diluted:
Diluted net earnings per share (in dollars per share)	$ 2.22	$ 1.65	$ 3.46	$ 2.78
Diluted comprehensive earnings per share (in dollars per share)	$ 2.35	$ 1.09	$ 3.84	$ 2.66
Weighted average number of common shares outstanding
Basic (in shares)	21,075	21,026	21,050	21,100
Diluted (in shares)	21,332	21,223	21,315	21,298
Cash dividends declared per common share (in dollars per share)	$ 0.30	$ 0.29	$ 0.59	$ 0.57