Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Consolidated Statements of Earnings and Comprehensive Earnings
Net premiums earned	$ 728,608	$ 700,161	$ 687,375
Net investment income	53,075	54,644	55,608
Net realized gains	34,740	39,829	32,182
Other-than-temporary-impairment losses on investments	(95)	0	0
Consolidated revenue	816,328	794,634	775,165
Losses and settlement expenses	349,778	299,045	296,609
Policy acquisition costs	249,612	241,078	229,283
Insurance operating expenses	53,093	51,480	54,464
Interest expense on debt	7,426	7,426	7,438
General corporate expenses	10,170	9,837	10,222
Total expenses	670,079	608,866	598,016
Equity in earnings of unconsolidated investees	10,833	10,914	12,338
Earnings before income taxes	157,082	196,682	189,487
Income tax expense:
Current	41,034	52,104	48,596
Deferred	1,128	7,034	5,446
Total tax expense	42,162	59,138	54,042
Net earnings	114,920	137,544	135,445
Other comprehensive earnings (loss), net of tax	(1,164)	(47,609)	35,356
Comprehensive earnings	$ 113,756	$ 89,935	$ 170,801
Basic:
Net earnings per share (in dollars per share)	$ 2.63	$ 3.18	$ 3.15
Comprehensive earnings per share (in dollars per share)	2.60	2.08	3.97
Diluted:
Net earnings per share (in dollars per share)	2.59	3.12	3.09
Comprehensive earnings per share (in dollars per share)	$ 2.56	$ 2.04	$ 3.90
Weighted average number of common shares outstanding
Basic (in shares)	43,772	43,299	43,020
Diluted (in shares)	44,432	44,131	43,819