Commitments and Contingencies - Summary of The Contractual Amount of Commitments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Contractual amount of commitments, total	$ 175,877	$ 163,932
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Contractual amount of commitments, total	83,129	74,206
Home Equity Loans
Loss Contingencies [Line Items]
Contractual amount of commitments, total	84,039	81,041
Standby letters of credit [Member]
Loss Contingencies [Line Items]
Contractual amount of commitments, total	$ 8,709	$ 8,685