Loans Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	$ 15,053	$ 14,745	$ 15,003	$ 14,689
Charge-offs	(136)	(150)	(433)	(388)
Recoveries	54	55	121	129
Provision	240	170	520	390
Allowance for Loan Losses, Ending Balance	15,211	14,820	15,211	14,820
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	765		765
Allowance for Credit Losses - Collectively Evaluated for Impairment	13,533	13,277	13,533	13,277	13,925
Ending Loan Balance - Individually Evaluated for Impairment	5,027	2,806	5,027	2,806	4,395
Ending Loan Balance - Collectively Evaluated for Impairment	1,141,614	1,117,290	1,141,614	1,117,290	1,127,062
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	1,834	1,476	1,927	2,037
Charge-offs	(10)	0	(15)	(50)
Recoveries	1	2	3	3
Provision	273	(402)	183	(914)
Allowance for Loan Losses, Ending Balance	2,098	1,076	2,098	1,076
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	765		765
Allowance for Credit Losses - Collectively Evaluated for Impairment	1,333	1,076	1,333	1,076	2,285
Ending Loan Balance - Individually Evaluated for Impairment	1,699	0	1,699	0	66
Ending Loan Balance - Collectively Evaluated for Impairment	99,595	97,201	99,595	97,201	99,725
Commercial Construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	661	134	602	135
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	(133)	509	(74)	508
Allowance for Loan Losses, Ending Balance	528	643	528	643
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for Credit Losses - Collectively Evaluated for Impairment	528	643	528	643	589
Ending Loan Balance - Individually Evaluated for Impairment	0	0	0	0	0
Ending Loan Balance - Collectively Evaluated for Impairment	17,628	6,907	17,628	6,907	11,083
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	3,297	4,314	3,136	2,993
Charge-offs	0	0	(167)	0
Recoveries	0	0	0	0
Provision	(2)	(700)	326	621
Allowance for Loan Losses, Ending Balance	3,295	3,614	3,295	3,614
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for Credit Losses - Collectively Evaluated for Impairment	3,295	3,614	3,295	3,614	3,167
Ending Loan Balance - Individually Evaluated for Impairment	1,625	994	1,625	994	1,953
Ending Loan Balance - Collectively Evaluated for Impairment	234,236	227,548	234,236	227,548	230,196
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	352	314	350	328
Charge-offs	(23)	(45)	(42)	(49)
Recoveries	3	17	9	22
Provision	23	18	38	3
Allowance for Loan Losses, Ending Balance	355	304	355	304
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for Credit Losses - Collectively Evaluated for Impairment	355	304	355	304	350
Ending Loan Balance - Individually Evaluated for Impairment	0	0	0	0	0
Ending Loan Balance - Collectively Evaluated for Impairment	6,543	5,981	6,543	5,981	6,318
Automobile [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	4,530	4,486	4,496	4,760
Charge-offs	(70)	(104)	(176)	(288)
Recoveries	50	36	109	104
Provision	61	178	142	20
Allowance for Loan Losses, Ending Balance	4,571	4,596	4,571	4,596
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for Credit Losses - Collectively Evaluated for Impairment	4,571	4,596	4,571	4,596	4,469
Ending Loan Balance - Individually Evaluated for Impairment	213	0	213	0	268
Ending Loan Balance - Collectively Evaluated for Impairment	333,885	316,692	333,885	316,692	322,107
Residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	3,300	2,902	3,414	3,163
Charge-offs	(33)	(1)	(33)	(1)
Recoveries	0	0	0	0
Provision	184	143	70	(118)
Allowance for Loan Losses, Ending Balance	3,451	3,044	3,451	3,044
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0		0
Allowance for Credit Losses - Collectively Evaluated for Impairment	3,451	3,044	3,451	3,044	3,065
Ending Loan Balance - Individually Evaluated for Impairment	1,490	1,812	1,490	1,812	2,108
Ending Loan Balance - Collectively Evaluated for Impairment	449,727	462,961	449,727	462,961	457,633
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	1,079	1,119	1,078	1,273
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	(166)	424	(165)	270
Allowance for Loan Losses, Ending Balance	$ 913	$ 1,543	$ 913	$ 1,543