Income Taxes (Details 5) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes
Reduction in income tax expense, net of the related federal tax effects, that would result in a realization of unrecognized tax benefits	$ 2,200,000
Accrued liabilities for interest and penalties related to uncertain tax positions	730,000	2,100,000
Interest and penalties on uncertain tax positions, income tax expense	316,000	271,000	280,000
Reduction in income tax expense, net of the related deferred tax effects, that would result in a realization of unrecognized tax benefits for the reversal of accrued interest and penalties	502,000
Bad Debt Reserve for Tax Purposes of US Savings and Loan Associations or Other Qualified Thrift Lender
Reconciliation of Provision of Income Taxes
Base year bad debt reserves	165,800,000	165,800,000
Unrecognized deferred federal income tax liability	$ 58,000,000	$ 58,000,000