Loans and Allowance for Loan Losses (Details 7) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Amounts of contractual interest income and interest income actually reflected in income on TDRs
Principal balance of TDRs at period end	$ 2,875	$ 1,473	$ 2,926
Gross interest income that would have been recorded if loans had not been restructured	32	21	165
Interest income actually included in income on TDRs	$ 30	$ 21	$ 165