Allowance for Loan Losses, Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
With no related allowance recorded [Abstract]
Recorded Investment	$ 6,349	$ 3,545	$ 6,349	$ 3,545	$ 4,648
Unpaid Principal Balance	6,451	3,767	6,451	3,767	4,913
Average Recorded Investment	4,826	3,657	4,183	3,310	3,645
Interest Income Recognized	19	4	51	10	25
With an allowance recorded [Abstract]
Recorded Investment	982	5,294	982	5,294	4,334
Unpaid Principal Balance	2,033	5,713	2,033	5,713	5,056
Related Allowance	962	1,742	962	1,742	1,636
Average Recorded Investment	1,012	6,678	1,655	5,081	4,896
Interest Income Recognized	3	47	5	73	116
Recorded Investment, Total	7,331	8,839	7,331	8,839	8,982
Unpaid Principal Balance, Total	8,484	9,480	8,484	9,480	9,969
Related Allowance, Total	962	1,742	962	1,742	1,636
Average Recorded Investment, Total	5,838	10,335	5,838	8,391	8,541
Interest Income Recognized, Total	22	51	56	83	141
Commercial Real Estate [Member]
With no related allowance recorded [Abstract]
Recorded Investment	295	816	295	816	1,555
Unpaid Principal Balance	295	811	295	811	1,547
Average Recorded Investment	297	530	789	453	729
Interest Income Recognized	6	0	15	0	0
With an allowance recorded [Abstract]
Recorded Investment	0	3,033	0	3,033	3,017
Unpaid Principal Balance	0	3,030	0	3,030	3,015
Related Allowance	0	702	0	702	686
Average Recorded Investment	0	3,041	503	2,035	2,281
Interest Income Recognized	0	44	0	46	89
Related Allowance, Total	0	702	0	702	686
Agricultural Real Estate [Member]
With no related allowance recorded [Abstract]
Recorded Investment	2,558	935	2,558	935	955
Unpaid Principal Balance	2,551	974	2,551	974	974
Average Recorded Investment	2,036	1,717	1,402	1,470	1,341
Interest Income Recognized	0	0	0	0	0
With an allowance recorded [Abstract]
Recorded Investment		463		463	0
Unpaid Principal Balance		823		823	0
Related Allowance		46		46	0
Average Recorded Investment		645		705	529
Interest Income Recognized		0		0	0
Related Allowance, Total		46		46	0
Residential 1st Mortgages [Member]
With no related allowance recorded [Abstract]
Recorded Investment	494	1,278	494	1,278	1,219
Unpaid Principal Balance	521	1,469	521	1,469	1,272
Average Recorded Investment	438	861	512	842	936
Interest Income Recognized	0	1	0	3	13
With an allowance recorded [Abstract]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment	54		72
Interest Income Recognized	0		0
Related Allowance, Total	0		0
Home Equity Lines and Loans [Member]
With no related allowance recorded [Abstract]
Recorded Investment	785	190	785	190	469
Unpaid Principal Balance	862	191	862	191	484
Average Recorded Investment	743	218	717	230	290
Interest Income Recognized	6	0	17	1	2
With an allowance recorded [Abstract]
Recorded Investment	269	73	269	73	113
Unpaid Principal Balance	314	82	314	82	119
Related Allowance	248	40	248	40	80
Average Recorded Investment	174	74	152	118	117
Interest Income Recognized	1	1	3	2	2
Related Allowance, Total	248	40	248	40	80
Agricultural [Member]
With no related allowance recorded [Abstract]
Recorded Investment	2,106	140	2,106	140	262
Unpaid Principal Balance	2,111	140	2,111	140	372
Average Recorded Investment	1,197	143	594	111	149
Interest Income Recognized	5	3	15	6	9
With an allowance recorded [Abstract]
Recorded Investment	547	1,533	547	1,533	1,076
Unpaid Principal Balance	1,551	1,548	1,551	1,548	1,791
Related Allowance	548	827	548	827	793
Average Recorded Investment	567	2,732	749	2,065	1,818
Interest Income Recognized	0	2	0	25	25
Related Allowance, Total	548	827	548	827	793
Commercial [Member]
With no related allowance recorded [Abstract]
Recorded Investment	111	186	111	186	188
Unpaid Principal Balance	111	182	111	182	264
Average Recorded Investment	115	188	169	197	195
Interest Income Recognized	2	0	4	0	1
With an allowance recorded [Abstract]
Recorded Investment	146	168	146	168	104
Unpaid Principal Balance	146	206	146	206	107
Related Allowance	146	103	146	103	54
Average Recorded Investment	196	155	157	125	120
Interest Income Recognized	2	0	2	0	0
Related Allowance, Total	146	103	146	103	54
Consumer & Other [Member]
With no related allowance recorded [Abstract]
Recorded Investment		0		0	0
Unpaid Principal Balance		0		0	0
Average Recorded Investment		0		7	5
Interest Income Recognized		0		0	0
With an allowance recorded [Abstract]
Recorded Investment	20	24	20	24	24
Unpaid Principal Balance	22	24	22	24	24
Related Allowance	20	24	20	24	23
Average Recorded Investment	21	31	22	33	31
Interest Income Recognized	0	0	0	0	0
Related Allowance, Total	$ 20	$ 24	$ 20	$ 24	$ 23