Acquisition - Valuation of fair value of assets acquired, and liabilities assumed, purchase price for Dupont State Bank acquisition (Details) (Dupont State Bank, USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended
	Nov. 09, 2012	Dec. 31, 2012
Dupont State Bank
Business Acquisition [Line Items]
Consideration: Cash paid	$ 5,700
Fair value of assets acquired:
Cash and cash equivalents	14,893
Investment securities available-for-sale	12,139
Loans	52,125
Property and equipment	3,160
Federal Home Loan Bank Stock	369
Real estate, held for sale	334
Core deposit intangible	514
Interest receivable	364
Other assets	1,243
Total assets acquired	85,141
Fair value of liabilities assumed:
Deposits	78,300
Interest payable	69
Other liabilities	84
Total liabilities assumed	78,453
Bargain purchase gain	$ (988)	$ (988)