Loans (Additional Information) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Specific reserves to customers whose loan terms have been modified in troubled debt restructurings	$ 0	$ 0
Charge-offs due to troubled debt restructurings	0	0
Defaulted payment following modification for troubled debt restructurings	0	857,000
Provision for Loan Losses	50,000		2,230,000
Allowance for Loan and Lease Losses, Period Increase (Decrease)	280,000
Troubled Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Loan and Lease Losses, Period Increase (Decrease)	0
Subsequently Defaulted [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Specific reserves to customers whose loan terms have been modified in troubled debt restructurings	$ 0	$ 108,000