Consolidated Statements of Earnings and Comprehensive Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statements of Earnings and Comprehensive Earnings
Net premiums earned	$ 630,802	$ 576,571	$ 538,452
Net investment income	52,763	58,831	63,681
Net realized investment gains	22,036	26,528	17,293
Other-than-temporary-impairment losses on investments		(1,156)	(257)
Consolidated revenue	705,601	660,774	619,169
Losses and settlement expenses	259,801	271,645	200,084
Policy acquisition costs	210,651	196,362	183,868
Insurance operating expenses	53,557	44,971	44,312
Interest expense on debt	8,095	6,050	6,050
General corporate expenses	8,746	7,867	7,766
Total expenses	540,850	526,895	442,080
Equity in earnings of unconsolidated investee	10,915	8,853	6,497
Earnings before income taxes	175,666	142,732	183,586
Income tax expense:
Current	43,346	35,605	49,524
Deferred	6,065	3,781	7,464
Income tax expense:	49,411	39,386	56,988
Net earnings	126,255	103,346	126,598
Other comprehensive earnings (loss), net of tax	(7,143)	25,845	21,333
Comprehensive earnings	$ 119,112	$ 129,191	$ 147,931
Basic:
Net earnings per share (in dollars per share)	$ 2.95	$ 2.44	$ 3.00
Comprehensive earnings per share (in dollars per share)	$ 2.79	$ 3.04	$ 3.51
Diluted:
Net earnings per share (in dollars per share)	$ 2.90	$ 2.39	$ 2.95
Comprehensive earnings per share (in dollars per share)	$ 2.74	$ 2.99	$ 3.45
Weighted average number of common shares outstanding
Basic (in shares)	42,744	42,431	42,156
Diluted (in shares)	43,514	43,160	42,869