Loans, Loans Portfolio Aging Analysis (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	$ 1,446	$ 1,270
60-89 Days Past Due	234	349
Greater Than 90 Days Past Due	2,862	2,249
Total Past Due	4,542	3,868
Current	545,125	449,915
Total gross loans	549,667	453,783	456,981
Total Loans Greater Than 90 Days and Accruing	180	128
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	0	0
60-89 Days Past Due	0	1
Greater Than 90 Days Past Due	181	264
Total Past Due	181	265
Current	35,234	25,945
Total gross loans	35,415	26,210
Total Loans Greater Than 90 Days and Accruing	0	0
Commercial Secured By Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	378	346
60-89 Days Past Due	0	79
Greater Than 90 Days Past Due	1,301	788
Total Past Due	1,679	1,213
Current	281,165	228,815
Total gross loans	282,844	230,028
Total Loans Greater Than 90 Days and Accruing	127	0
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	945	791
60-89 Days Past Due	223	212
Greater Than 90 Days Past Due	1,376	1,172
Total Past Due	2,544	2,175
Current	211,940	181,195
Total gross loans	214,484	183,370
Total Loans Greater Than 90 Days and Accruing	49	103
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	60	61
60-89 Days Past Due	11	57
Greater Than 90 Days Past Due	4	25
Total Past Due	75	143
Current	13,898	10,488
Total gross loans	13,973	10,631
Total Loans Greater Than 90 Days and Accruing	4	25
Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	1,805	1,668
Total gross loans	1,805	1,668
Total Loans Greater Than 90 Days and Accruing	0	0
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 -59 Days Past Due	63	72
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	63	72
Current	1,083	1,804
Total gross loans	1,146	1,876
Total Loans Greater Than 90 Days and Accruing	$ 0	$ 0