Statutory Insurance Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments	$ 93,000,000
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	547,398,000	509,151,000
Statutory accounting practices, net gain from operations	92,988,000	87,792,000	65,149,000
Statutory Accounting Practices, Statutory Net Income Amount	$ 86,589,000	$ 72,653,000	$ 72,296,000