Loans, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	$ 408	$ 410
Collectively evaluated for impairment	11,179	10,780
Total	11,587	11,190	$ 9,405	$ 8,886
Real Estate Loans [Member] \| Residential [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	38	56
Collectively evaluated for impairment	1,039	993
Total	1,077	1,049	1,042	1,064
Real Estate Loans [Member] \| Commercial [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	170	94
Collectively evaluated for impairment	3,836	3,773
Total	4,006	3,867	3,665	3,589
Real Estate Loans [Member] \| Agricultural [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	5	3
Collectively evaluated for impairment	3,335	3,140
Total	3,340	3,143	1,952	1,494
Real Estate Loans [Member] \| Construction [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	39	23
Total	39	23	46	47
Consumer [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	123	124
Total	123	124	123	122
Other Commercial Loans [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	184	231
Collectively evaluated for impairment	1,089	1,041
Total	1,273	1,272	1,215	1,327
Other Agricultural Loans [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	11	26
Collectively evaluated for impairment	521	466
Total	532	492	306	312
State and Political Subdivision Loans [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	789	816
Total	789	816	824	833
Unallocated [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	408	404
Total	$ 408	$ 404	$ 232	$ 98

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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