Income Taxes (Deferred Tax Components) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets:
Reserve for losses and loss expenses	$ 22,843	$ 20,580
Equity compensation	13,012	15,920
Unearned premium	12,688	11,382
Deferred acquisition costs	10,843	8,506
Other than temporary impairments	408	506
Mark to market on securities acquired	114	80
Total deferred tax assets	59,908	56,974
Deferred tax liabilities:
Intangible assets	(15,629)	(16,500)
Realized gains	(11,372)	(6,317)
Depreciation	(3,509)	(4,391)
Unrealized appreciation and timing differences on investments	(293)	(3,135)
Market discount on bonds	(727)	(1,032)
Other	(2,798)	(2,953)
Total deferred tax liabilities	(34,328)	(34,328)
Net deferred tax assets	$ 25,580	$ 22,646