Summary of Significant Accounting Policies (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Loans [Abstract]
Number of days of delinquent loans, interest accrual discontinued	90 days
Minimum number of days of discontinued loan payments for modified loan to be placed on nonaccrual	90 days
Number of days past due	30 days
Allowance for Loan Losses [Abstract]
Threshold for designation to impaired status	$ 250,000
Minimum number of days consumer loans are past due for losses to be charged off	120 days
Maximum number of days consumer loans are past due for losses to be charged off	180 days
Number of days loans secured by residential or commercial real estate are past due for losses to be charged off	180 days
Rate Lock Commitments [Abstract]
Period of time between issuance of loan commitment and closing and sale of loans, lower range	30 days
Period of time between issuance of loan commitments and closing and sale of loans, upper range	60 days
Earnings per common share [Abstract]
Average number of common shares outstanding (in shares)	6,942,411	6,936,869	6,933,474
Effect of dilutive options (in shares)	17,456	13,994	16,462
Average number of common shares outstanding used to calculate diluted earnings per common share (in shares)	6,959,867	6,950,863	6,949,936
Average number of shares not included in computation of diluted net income per common share (in shares)	0	5,750	7,750
Advertising [Abstract]
Advertising cost charged to expenses	$ 169	$ 184	$ 163
Minimum [Member] | Customer Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	10 years
Maximum [Member] | Customer Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life	12 years
Premises [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years