Summary of Significant Accounting Policies Change in Accouting Estimate (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Change in Accounting Estimate [Line Items]
Net earned premium	$ 33,893	$ 28,673	$ 97,770	$ 84,646
Ceding commission	11,122	7,027	25,396	21,428
Commissions	21,548	17,926	61,479	53,766
Other operating expenses	7,959	7,267	21,635	23,779
Income taxes	2,455	2,259	6,520	4,847
Change in Accounting Method Accounted for as Change in Estimate [Member]
Change in Accounting Estimate [Line Items]
Net earned premium	1,845		1,845
Ceding commission	2,135		2,135
Net increase to total revenues from the change in accounting estimate	3,980		3,980
Commissions	2,739		2,739
Other operating expenses	(268)		(268)
Net increase to total expenses from the change in accounting estimate	2,471		2,471
Net increase to income before income taxes from the change in accounting estimate	1,509		1,509
Income taxes	533		533
Net increase to net income from the change in accounting estimate	$ 976		$ 976
Earnings Per Share, Basic	$ 0.05		$ 0.05
Earnings Per Share, Diluted	$ 0.05		$ 0.05