Condensed Consolidated Statements of Earnings and Comprehensive Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Condensed Consolidated Statements of Earnings and Comprehensive Earnings
Net premiums earned	$ 144,151	$ 137,280
Net investment income	12,886	15,293
Net realized investment gains	3,684	11,416
Consolidated revenue	160,721	163,989
Losses and settlement expenses	61,448	61,883
Policy acquisition costs	50,336	48,197
Insurance operating expenses	12,569	12,259
Interest expense on debt	1,512	1,500
General corporate expenses	2,386	1,987
Total expenses	128,251	125,826
Equity in earnings of unconsolidated investee	3,499	2,946
Earnings before income taxes	35,969	41,109
Income tax expense	11,122	13,071
Net earnings	24,847	28,038
Other comprehensive earnings, net of tax	17,553	10,776
Comprehensive earnings	$ 42,400	$ 38,814
Basic:
Basic net earnings per share (in dollars per share)	$ 1.17	$ 1.32
Basic comprehensive earnings per share (in dollars per share)	$ 1.99	$ 1.83
Diluted:
Diluted net earnings per share (in dollars per share)	$ 1.15	$ 1.30
Diluted comprehensive earnings per share (in dollars per share)	$ 1.96	$ 1.80
Weighted average number of common shares outstanding
Basic (in shares)	21,272	21,188
Diluted (in shares)	21,623	21,528
Cash dividends declared per common share (in dollars per share)	$ 0.32	$ 0.30