Loans Loan Categories and Past Due Loans(Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	$ 5,272	$ 4,456	$ 3,835
Loans Past Due 60 - 89 Days	2,064	6,196	1,380
Loans Past Due 90 or more Days	3,416	4,012	3,959
Total Loans Past Due	10,752	14,664	9,174
Current Loans	1,154,007	1,157,677	1,128,373
Total Loans	1,164,759	1,172,341	1,137,547
Loans 90 Days or More Past Due and Still Accruing Interest	259	920	121
Nonaccrual Loans	5,218	6,633	5,476
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	428	1,045	368
Loans Past Due 60 - 89 Days	421	1,588	44
Loans Past Due 90 or more Days	130	494	9
Total Loans Past Due	979	3,127	421
Current Loans	88,188	102,409	101,732
Total Loans	89,167	105,536	102,153
Loans 90 Days or More Past Due and Still Accruing Interest	0	126	9
Nonaccrual Loans	253	1,787	35
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	27,380	29,149	10,814
Total Loans	27,380	29,149	10,814
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	1,351	534	427
Loans Past Due 60 - 89 Days	200	1,332	117
Loans Past Due 90 or more Days	1,886	1,871	1,073
Total Loans Past Due	3,437	3,737	1,617
Current Loans	251,805	241,440	232,700
Total Loans	255,242	245,177	234,317
Loans 90 Days or More Past Due and Still Accruing Interest	0	378	0
Nonaccrual Loans	1,953	2,026	1,925
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	26	43	21
Loans Past Due 60 - 89 Days	10	17	20
Loans Past Due 90 or more Days	0	0	15
Total Loans Past Due	36	60	56
Current Loans	6,995	6,624	6,414
Total Loans	7,031	6,684	6,470
Loans 90 Days or More Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	4	1	15
Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	1,986	2,427	1,930
Loans Past Due 60 - 89 Days	375	793	256
Loans Past Due 90 or more Days	98	185	158
Total Loans Past Due	2,459	3,405	2,344
Current Loans	351,542	345,695	326,332
Total Loans	354,001	349,100	328,676
Loans 90 Days or More Past Due and Still Accruing Interest	0	42	0
Nonaccrual Loans	334	419	500
Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due 30 - 59 Days	1,481	407	1,089
Loans Past Due 60 - 89 Days	1,058	2,466	943
Loans Past Due 90 or more Days	1,302	1,462	2,704
Total Loans Past Due	3,841	4,335	4,736
Current Loans	428,097	432,360	450,381
Total Loans	431,938	436,695	455,117
Loans 90 Days or More Past Due and Still Accruing Interest	259	374	112
Nonaccrual Loans	$ 2,674	$ 2,400	$ 3,001