Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Gross written premiums	$ 393,222	$ 343,149
Revenues:
Net written premiums	269,452	243,045
Change in unearned premiums	(67,124)	(59,926)
Net earned premiums	202,328	183,119
Net investment income	13,657	11,258
Total other-than-temporary impairment losses	(42)	(198)
Portion of loss recognized in other comprehensive income (before tax)		44
Net other-than-temporary impairment losses recognized in earnings	(42)	(154)
Net realized gains (losses)	4,814	1,842
Other income (expense)	618	911
Total revenues	221,375	196,976
Expenses:
Net losses and loss adjustment expenses	131,342	117,985
Commission expenses	26,555	29,450
Other operating expenses	40,874	36,307
Interest expense	2,051	2,049
Total expenses	200,822	185,791
Income (loss) before income taxes	20,553	11,185
Income tax expense (benefit)	6,643	3,281
Net income (loss)	$ 13,910	$ 7,904
Net income per common share:
Basic	$ 0.99	$ 0.57
Diluted	$ 0.97	$ 0.56
Average common shares outstanding:
Basic	14,085,821	13,979,442
Diluted	14,374,957	14,174,875