Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Impaired loans measured at fair value on a nonrecurring basis
Impaired loans, Carrying value	$ 11,372	$ 7,644
Impaired loans, Provision for Loan Losses	$ 106	$ 71