Financial Instruments with Off-Balance Sheet Risk (Details) (USD $) In Thousands, unless otherwise specified									12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Undisbursed Loan Commitments [Member]	Dec. 31, 2011 Undisbursed Loan Commitments [Member]	Dec. 31, 2012 Commitments to Sell Loans [Member]	Dec. 31, 2011 Commitments to Sell Loans [Member]	Dec. 31, 2012 Standby Letters of Credit [Member]	Dec. 31, 2011 Standby Letters of Credit [Member]	Dec. 31, 2012 Performance Standby Letters of Credit [Member]	Dec. 31, 2012 Derivative [Member]	Dec. 31, 2012 Reserve for Off-balance Sheet Activity [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet credit risks	$ 169,185	$ 156,180	$ 159,329	$ 146,778	$ 7,480	$ 7,530	$ 2,376	$ 1,872	$ 2,376	$ 0	$ 793
Expiration year of guarantees									2013