Loans, Impaired Financing Receivable (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	$ 12,428		$ 12,428		$ 12,066
Recorded Investment With No Allowance	7,308		7,308		7,218
Recorded Investment With Allowance	3,578		3,578		3,200
Total Recorded Investment	10,886		10,886		10,418
Related Allowance	598		598		582
Average Recorded Investment	10,508	8,146	10,735	8,569
Interest income recognized on impaired loans	362	37	493	79
Interest income recognized on a cash basis on impaired loans	326	22	361	46
Mortgages [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	349	253	336	139
Interest income recognized on impaired loans	2	1	6	2
Interest income recognized on a cash basis on impaired loans	0	0	0	0
Home Equity [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	135	113	136	100
Interest income recognized on impaired loans	1	1	3	3
Interest income recognized on a cash basis on impaired loans	0	0	0	1
Commercial [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	8,372	7,398	8,521	7,891
Interest income recognized on impaired loans	342	35	426	74
Interest income recognized on a cash basis on impaired loans	326	22	361	45
Agricultural [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	0	0	0	0
Interest income recognized on impaired loans	0	0	0	0
Interest income recognized on a cash basis on impaired loans	0	0	0	0
Construction [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment			0	0
Interest income recognized on impaired loans			0	0
Interest income recognized on a cash basis on impaired loans			0	0
Real Estate Loans [Member] | Mortgages [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	375		375		309
Recorded Investment With No Allowance	141		141		150
Recorded Investment With Allowance	206		206		136
Total Recorded Investment	347		347		286
Related Allowance	24		24		8
Real Estate Loans [Member] | Home Equity [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	135		135		138
Recorded Investment With No Allowance	0		0		0
Recorded Investment With Allowance	135		135		138
Total Recorded Investment	135		135		138
Related Allowance	13		13		14
Real Estate Loans [Member] | Commercial [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	10,052		10,052		10,669
Recorded Investment With No Allowance	5,714		5,714		6,476
Recorded Investment With Allowance	2,880		2,880		2,617
Total Recorded Investment	8,594		8,594		9,093
Related Allowance	560		560		559
Real Estate Loans [Member] | Agricultural [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	0		0		0
Recorded Investment With No Allowance	0		0		0
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	0		0		0
Related Allowance	0		0		0
Real Estate Loans [Member] | Construction [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	0		0		0
Recorded Investment With No Allowance	0		0		0
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	0		0		0
Related Allowance	0		0		0
Consumer [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	15		15		0
Recorded Investment With No Allowance	15		15		0
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	15		15		0
Related Allowance	0		0		0
Average Recorded Investment	5	0	2	0
Interest income recognized on impaired loans	0	0	0	0
Interest income recognized on a cash basis on impaired loans	0	0	0	0
Consumer [Member] | Construction [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	0	0
Interest income recognized on impaired loans	0	0
Interest income recognized on a cash basis on impaired loans	0	0
Other Commercial Loans [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	1,851		1,851		950
Recorded Investment With No Allowance	1,438		1,438		592
Recorded Investment With Allowance	357		357		309
Total Recorded Investment	1,795		1,795		901
Related Allowance	1		1		1
Average Recorded Investment	1,647	382	1,740	439
Interest income recognized on impaired loans	17	0	58	0
Interest income recognized on a cash basis on impaired loans	0	0	0	0
Other Agricultural Loans [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	0		0		0
Recorded Investment With No Allowance	0		0		0
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	0		0		0
Related Allowance	0		0		0
Average Recorded Investment	0	0	0	0
Interest income recognized on impaired loans	0	0	0	0
Interest income recognized on a cash basis on impaired loans	0	0	0	0
State and Political Subdivision Loans [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	0		0		0
Recorded Investment With No Allowance	0		0		0
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	0		0		0
Related Allowance	0		0		0
Average Recorded Investment	0	0	0	0
Interest income recognized on impaired loans	0	0	0	0
Interest income recognized on a cash basis on impaired loans	$ 0	$ 0	$ 0	$ 0