Loans, Impaired Financing Receivable (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	$ 12,363		$ 12,363		$ 12,066
Recorded Investment With No Allowance	7,314		7,314		7,218
Recorded Investment With Allowance	3,279		3,279		3,200
Total Recorded Investment	10,593		10,593		10,418
Related Allowance	537		537		582
Average Recorded Investment	10,810	8,764	10,848	8,782
Interest income recognized on impaired loans	64	23	131	42
Interest income recognized on a cash basis on impaired loans	21	5	35	24
Mortgages [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	352	165	330	83
Interest income recognized on impaired loans	2	1	4	1
Interest income recognized on a cash basis on impaired loans	0	0	0	0
Home Equity [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	136	93	137	93
Interest income recognized on impaired loans	1	1	2	2
Interest income recognized on a cash basis on impaired loans	0	0	0	1
Commercial [Member]
Impaired Financing Receivable [Abstract]
Average Recorded Investment	8,406	8,049	8,595	8,138
Interest income recognized on impaired loans	39	21	84	39
Interest income recognized on a cash basis on impaired loans	21	5	35	23
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	376		376		309
Recorded Investment With No Allowance	144		144		150
Recorded Investment With Allowance	207		207		136
Total Recorded Investment	351		351		286
Related Allowance	24		24		8
Real Estate Loans [Member] | Home Equity [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	136		136		138
Recorded Investment With No Allowance	0		0		0
Recorded Investment With Allowance	136		136		138
Total Recorded Investment	136		136		138
Related Allowance	13		13		14
Real Estate Loans [Member] | Commercial [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	10,023		10,023		10,669
Recorded Investment With No Allowance	5,704		5,704		6,476
Recorded Investment With Allowance	2,628		2,628		2,617
Total Recorded Investment	8,332		8,332		9,093
Related Allowance	499		499		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	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
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	1,828		1,828		950
Recorded Investment With No Allowance	1,466		1,466		592
Recorded Investment With Allowance	308		308		309
Total Recorded Investment	1,774		1,774		901
Related Allowance	1		1		1
Average Recorded Investment	1,916	457	1,786	468
Interest income recognized on impaired loans	22	0	41	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