Loans Loan Categories and Past Due Loans(Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	$ 6,042	$ 5,953	$ 3,513
Loans Past Due 60 - 89 Days	4,122	1,105	2,135
Loans Past Due 90 or more Days	2,263	5,218	3,683
Total Loans Past Due	12,427	12,276	9,331
Current Loans	1,140,524	1,119,181	1,111,360
Total Loans	1,152,951	1,131,457	1,120,691
Loans 90 Days or More Past Due and Still Accruing Interest	150	1,662	826
Nonaccrual Loans	6,088	4,528	4,265
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	831	538	432
Loans Past Due 60 - 89 Days	1,764	197	134
Loans Past Due 90 or more Days	216	17	21
Total Loans Past Due	2,811	752	587
Current Loans	97,612	99,039	96,444
Total Loans	100,423	99,791	97,031
Loans 90 Days or More Past Due and Still Accruing Interest	0	17	0
Nonaccrual Loans	1,750	6	41
Commercial Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	0	0	0
Loans Past Due 60 - 89 Days	0	0	0
Loans Past Due 90 or more Days	0	0	0
Total Loans Past Due	0	0	0
Current Loans	27,265	11,083	8,642
Total Loans	27,265	11,083	8,642
Loans 90 Days or More Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	0	0	0
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	271	284	0
Loans Past Due 60 - 89 Days	1,051	0	218
Loans Past Due 90 or more Days	621	1,825	1,425
Total Loans Past Due	1,943	2,109	1,643
Current Loans	233,238	230,040	226,965
Total Loans	235,181	232,149	228,608
Loans 90 Days or More Past Due and Still Accruing Interest	0	684	300
Nonaccrual Loans	1,156	1,503	1,199
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	20	75	44
Loans Past Due 60 - 89 Days	0	12	6
Loans Past Due 90 or more Days	0	6	0
Total Loans Past Due	20	93	50
Current Loans	6,837	6,225	6,030
Total Loans	6,857	6,318	6,080
Loans 90 Days or More Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	1	6	0
Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	2,675	3,512	2,821
Loans Past Due 60 - 89 Days	485	670	853
Loans Past Due 90 or more Days	148	314	251
Total Loans Past Due	3,308	4,496	3,925
Current Loans	339,922	317,879	311,300
Total Loans	343,230	322,375	315,225
Loans 90 Days or More Past Due and Still Accruing Interest	0	56	0
Nonaccrual Loans	419	431	495
Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	2,245	1,544	216
Loans Past Due 60 - 89 Days	822	226	924
Loans Past Due 90 or more Days	1,278	3,056	1,986
Total Loans Past Due	4,345	4,826	3,126
Current Loans	435,650	454,915	461,979
Total Loans	439,995	459,741	465,105
Loans 90 Days or More Past Due and Still Accruing Interest	150	905	526
Nonaccrual Loans	$ 2,762	$ 2,582	$ 2,530