Loans Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	$ 15,211	$ 14,820	$ 15,003	$ 14,689
Charge-offs	(171)	(135)	(604)	(523)
Recoveries	57	60	178	189
Provision	150	175	670	565
Allowance for Loan Losses, Ending Balance	15,247	14,920	15,247	14,920
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	809		809
Allowance for loan losses - Loans Collectively Evaluated for Impairment	13,480	13,464	13,480	13,464	13,925
Ending Loan Balance - Individually Evaluated for Impairment	4,843	2,806	4,843	2,806	4,395
Ending Loan Balance - Collectively Evaluated for Impairment	1,148,108	1,117,885	1,148,108	1,117,885	1,127,062
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	2,098	1,076	1,927	2,037
Charge-offs	0	0	(15)	(50)
Recoveries	2	1	5	4
Provision	22	265	205	(649)
Allowance for Loan Losses, Ending Balance	2,122	1,342	2,122	1,342
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	809		809
Allowance for loan losses - Loans Collectively Evaluated for Impairment	1,313	1,342	1,313	1,342	1,927
Ending Loan Balance - Individually Evaluated for Impairment	1,553	0	1,553	0	66
Ending Loan Balance - Collectively Evaluated for Impairment	98,870	97,031	98,870	97,031	99,725
Commercial Construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	528	643	602	135
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	19	(282)	(55)	226
Allowance for Loan Losses, Ending Balance	547	361	547	361
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for loan losses - Loans Collectively Evaluated for Impairment	547	361	547	361	602
Ending Loan Balance - Individually Evaluated for Impairment	0	0	0	0	0
Ending Loan Balance - Collectively Evaluated for Impairment	27,265	8,642	27,265	8,642	11,083
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	3,295	3,614	3,136	2,993
Charge-offs	(39)	0	(206)	0
Recoveries	0	0	0	0
Provision	(82)	327	244	948
Allowance for Loan Losses, Ending Balance	3,174	3,941	3,174	3,941
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for loan losses - Loans Collectively Evaluated for Impairment	3,174	3,941	3,174	3,941	3,136
Ending Loan Balance - Individually Evaluated for Impairment	1,574	994	1,574	994	1,953
Ending Loan Balance - Collectively Evaluated for Impairment	233,607	227,614	233,607	227,614	230,196
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	355	304	350	328
Charge-offs	(27)	(22)	(69)	(71)
Recoveries	8	14	17	36
Provision	(11)	40	27	43
Allowance for Loan Losses, Ending Balance	325	336	325	336
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for loan losses - Loans Collectively Evaluated for Impairment	325	336	325	336	350
Ending Loan Balance - Individually Evaluated for Impairment	0	0	0	0	0
Ending Loan Balance - Collectively Evaluated for Impairment	6,857	6,080	6,857	6,080	6,318
Automobile [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	4,571	4,596	4,496	4,760
Charge-offs	(105)	(79)	(281)	(367)
Recoveries	47	45	156	149
Provision	119	(151)	261	(131)
Allowance for Loan Losses, Ending Balance	4,632	4,411	4,632	4,411
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for loan losses - Loans Collectively Evaluated for Impairment	4,632	4,411	4,632	4,411	4,496
Ending Loan Balance - Individually Evaluated for Impairment	204	0	204	0	268
Ending Loan Balance - Collectively Evaluated for Impairment	343,026	315,225	343,026	315,225	322,107
Residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	3,451	3,044	3,414	3,163
Charge-offs	0	(34)	(33)	(35)
Recoveries	0	0	0	0
Provision	38	63	108	(55)
Allowance for Loan Losses, Ending Balance	3,489	3,073	3,489	3,073
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for loan losses - Loans Collectively Evaluated for Impairment	3,489	3,073	3,489	3,073	3,414
Ending Loan Balance - Individually Evaluated for Impairment	1,512	1,812	1,512	1,812	2,108
Ending Loan Balance - Collectively Evaluated for Impairment	438,483	463,293	438,483	463,293	457,633
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	913	1,543	1,078	1,273
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	45	(87)	(120)	183
Allowance for Loan Losses, Ending Balance	$ 958	$ 1,456	$ 958	$ 1,456