Loans, Impaired Financing Receivable (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	$ 20,530		$ 20,127
Recorded Investment With No Allowance	15,050		15,031
Recorded Investment With Allowance	2,613		2,662
Total Recorded Investment	17,663		17,693
Related Allowance	404		487
Average Recorded Investment	17,350	$ 12,852
Interest Income Recognized	122	100
Interest Income Recognized Cash Basis	13	1
Real Estate Loans [Member] \| Mortgages [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	949		953
Recorded Investment With No Allowance	568		570
Recorded Investment With Allowance	322		330
Total Recorded Investment	890		900
Related Allowance	28		22
Average Recorded Investment	894	391
Interest Income Recognized	3	4
Interest Income Recognized Cash Basis	0	0
Real Estate Loans [Member] \| Home Equity [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	55		57
Recorded Investment With No Allowance	0		0
Recorded Investment With Allowance	55		57
Total Recorded Investment	55		57
Related Allowance	10		10
Average Recorded Investment	56	60
Interest Income Recognized	1	1
Interest Income Recognized Cash Basis	0	0
Real Estate Loans [Member] \| Commercial [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	8,628		7,958
Recorded Investment With No Allowance	5,937		5,697
Recorded Investment With Allowance	410		45
Total Recorded Investment	6,347		5,742
Related Allowance	47		45
Average Recorded Investment	5,793	6,179
Interest Income Recognized	24	26
Interest Income Recognized Cash Basis	3	0
Real Estate Loans [Member] \| Agricultural [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	3,487		3,347
Recorded Investment With No Allowance	2,146		2,000
Recorded Investment With Allowance	1,330		1,347
Total Recorded Investment	3,476		3,347
Related Allowance	103		54
Average Recorded Investment	3,382	165
Interest Income Recognized	31	2
Interest Income Recognized Cash Basis	0	0
Real Estate Loans [Member] \| Construction [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	0		0
Recorded Investment With No Allowance	0		0
Recorded Investment With Allowance	0		0
Total Recorded Investment	0		0
Related Allowance	0		0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Interest Income Recognized Cash Basis	0	0
Consumer [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	2		0
Recorded Investment With No Allowance	0		0
Recorded Investment With Allowance	2		0
Total Recorded Investment	2		0
Related Allowance	2		0
Average Recorded Investment	1	0
Interest Income Recognized	0	0
Interest Income Recognized Cash Basis	0	0
Other Commercial Loans [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	5,797		6,159
Recorded Investment With No Allowance	4,806		5,135
Recorded Investment With Allowance	475		859
Total Recorded Investment	5,281		5,994
Related Allowance	195		326
Average Recorded Investment	5,597	5,952
Interest Income Recognized	40	66
Interest Income Recognized Cash Basis	10	1
Other Agricultural Loans [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	1,612		1,653
Recorded Investment With No Allowance	1,593		1,629
Recorded Investment With Allowance	19		24
Total Recorded Investment	1,612		1,653
Related Allowance	19		30
Average Recorded Investment	1,627	105
Interest Income Recognized	23	1
Interest Income Recognized Cash Basis	0	0
State and Political Subdivision Loans [Member]
Impaired Financing Receivable [Abstract]
Unpaid Principal Balance	0		0
Recorded Investment With No Allowance	0		0
Recorded Investment With Allowance	0		0
Total Recorded Investment	0		0
Related Allowance	0		$ 0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Interest Income Recognized Cash Basis	$ 0	$ 0

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- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5258-111524

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953550-111524

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Amount of allowance for credit losses related to recorded investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

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