CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Gross written premiums	$ 1,108,216	$ 987,201	$ 1,044,918
Revenues:
Net written premiums	753,798	653,938	701,255
Change in unearned premiums	(62,153)	5,993	(17,892)
Net earned premiums	691,645	659,931	683,363
Net investment income	63,500	71,662	75,512
Total other-than-temporary impairment losses	(3,617)	(2,222)	(29,265)
Portion of loss recognized in other comprehensive income (before tax)	1,632	1,142	17,388
Net other-than-temporary impairment losses recognized in earnings	(1,985)	(1,080)	(11,877)
Net realized gains (losses)	11,996	41,319	9,217
Other income (expense)	1,229	5,143	6,665
Total revenues	766,385	776,975	762,880
Expenses:
Net losses and loss adjustment expenses	476,997	421,155	435,998
Commission expenses	110,437	109,113	98,908
Other operating expenses	138,029	139,700	132,671
Interest expense	8,188	8,178	8,455
Total expenses	733,651	678,146	676,032
Income (loss) before income taxes	32,734	98,829	86,848
Income tax expense (benefit)	7,137	29,251	23,690
Net income (loss)	$ 25,597	$ 69,578	$ 63,158
Net income per common share:
Basic	$ 1.71	$ 4.33	$ 3.73
Diluted	$ 1.69	$ 4.24	$ 3.65
Average common shares outstanding:
Basic	14,980,429	16,064,770	16,935,488
Diluted	15,183,285	16,415,266	17,322,020