Loans (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment	$ 753	$ 1,265
Allowance for loan losses, Collectively evaluated for impairment	12,208	11,122
Allowance for loan losses, Modified in a troubled debt restructuring	1,099	228
Total ending allowance balance	14,060	12,615	10,820	9,795
Loans:
Loans individually evaluated for impairment	13,899	14,696
Loans collectively evaluated for impairment	905,705	830,385
Loans modified in a troubled debt restructuring	11,621	7,688
Total ending loans balance	931,225	852,769
Commercial, Industrial, and Agricultural [Member]
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment	541	329
Allowance for loan losses, Collectively evaluated for impairment	4,399	4,182
Allowance for loan losses, Modified in a troubled debt restructuring
Total ending allowance balance	4,940	4,511	3,517
Loans:
Loans individually evaluated for impairment	2,623	6,115
Loans collectively evaluated for impairment	253,048	247,209
Loans modified in a troubled debt restructuring	1,420
Total ending loans balance	257,091	253,324
Commercial Mortgages [Member]
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment	131	917
Allowance for loan losses, Collectively evaluated for impairment	3,467	3,325
Allowance for loan losses, Modified in a troubled debt restructuring	1,099	228
Total ending allowance balance	4,697	4,470	3,511
Loans:
Loans individually evaluated for impairment	10,683	8,457
Loans collectively evaluated for impairment	240,907	226,366
Loans modified in a troubled debt restructuring	10,201	7,688
Total ending loans balance	261,791	242,511
Residential Real Estate [Member]
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment	81	19
Allowance for loan losses, Collectively evaluated for impairment	2,385	1,972
Allowance for loan losses, Modified in a troubled debt restructuring
Total ending allowance balance	2,466	1,991	1,916
Loans:
Loans individually evaluated for impairment	593	124
Loans collectively evaluated for impairment	347,311	298,504
Loans modified in a troubled debt restructuring
Total ending loans balance	347,904	298,628
Consumer [Member]
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment
Allowance for loan losses, Collectively evaluated for impairment	1,699	1,404
Allowance for loan losses, Modified in a troubled debt restructuring
Total ending allowance balance	1,699	1,404	1,561
Loans:
Loans individually evaluated for impairment
Loans collectively evaluated for impairment	58,668	53,471
Loans modified in a troubled debt restructuring
Total ending loans balance	58,668	53,471
Credit Cards [Member]
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment
Allowance for loan losses, Collectively evaluated for impairment	83	71
Allowance for loan losses, Modified in a troubled debt restructuring
Total ending allowance balance	83	71	96
Loans:
Loans individually evaluated for impairment
Loans collectively evaluated for impairment	4,800	4,412
Loans modified in a troubled debt restructuring
Total ending loans balance	4,800	4,412
Overdrafts [Member]
Ending allowance balance attributable to loans:
Allowance for loan losses, Individually evaluated for impairment
Allowance for loan losses, Collectively evaluated for impairment	175	168
Allowance for loan losses, Modified in a troubled debt restructuring
Total ending allowance balance	175	168	219
Loans:
Loans individually evaluated for impairment
Loans collectively evaluated for impairment	971	423
Loans modified in a troubled debt restructuring
Total ending loans balance	$ 971	$ 423