Loans (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 794,045,000	$ 788,705,000
Interest income, including accretion, on loans	9,500,000
Accretion income included in interest income	3,900,000
Loan pay offs and renewals amount included in interest income	976,000
Outstanding principal balance and the carrying amount of loan acquired [Abstract]
Outstanding principal balance	173,073,000	219,569,000
Carrying amount	160,672,000	203,981,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Outstanding principal balance	23,672,000	26,349,000
Carrying amount	17,999,000	20,182,000
Changes in the accretable discount on acquired loans [Abstract]
Balance, beginning of period	2,165,000
Accretion	(1,222,000)
Reclassification from nonaccretable difference	1,026,000
Balance, end of period	1,969,000
Accretion reflected	976,000
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	130,721,000	126,192,000
Commercial real estate, portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	398,352,000	404,245,000
Commercial real estate, portfolio [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	44,029,000	48,812,000
Commercial real estate, portfolio [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	354,323,000	355,433,000
Residential real estate, portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	258,653,000	252,346,000
Residential real estate, portfolio [Member] | Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	168,965,000	161,033,000
Residential real estate, portfolio [Member] | Home equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	89,688,000	91,313,000
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 6,319,000	$ 5,922,000