Quarterly Information (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Data [Abstract]

Quarterly Financial Data (Unaudited)

			Fourth Quarter				Third Quarter				Second Quarter				First Quarter
			2014		2013		2014		2013		2014		2013		2014		2013
Net earned premium			$	601,832	$	560,030	$	586,935	$	556,668	$	572,248	$	561,356	$	562,612	$	561,186
Other revenue				68,175		76,600		103,103		79,809		71,326		68,075		86,318		73,180
	Total revenue			670,007		636,630		690,038		636,477		643,574		629,431		648,930		634,366
Loss and LAE expense				339,434		305,477		320,758		328,530		335,897		347,353		330,746		341,094
Other expense				166,010		174,770		164,623		167,847		170,033		157,247		163,212		141,876
	Total expense			505,444		480,247		485,381		496,377		505,930		504,600		493,958		482,970
Earnings before income taxes				164,563		156,383		204,657		140,100		137,644		124,831		154,972		151,396
Income tax expense				51,534		41,373		64,390		41,925		40,508		36,669		47,061		45,546
	Net earnings		$	113,029	$	115,010	$	140,267	$	98,175	$	97,136	$	88,162	$	107,911	$	105,850
Earnings per share
	Basic		$	1.17	$	1.15	$	1.41	$	0.98	$	0.97	$	0.88	$	1.08	$	1.05
	Diluted			1.16		1.14		1.41		0.98		0.97		0.87		1.07		1.05
Weighted-average shares
	outstanding
		Basic		95,373		98,770		97,909		98,723		98,442		98,870		98,662		99,056
		Diluted		95,636		99,046		98,134		98,993		98,660		99,121		98,913		99,287