Loans and ALLL (Summary of changes in ALLL by segments) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	$ 8,375	$ 7,700
Allowance for loan losses, Charge-offs	(138)	(103)
Allowance for loan losses, Recoveries	127	219
Allowance for loan losses, Provision for loan losses	34	384
Allowance for loan losses, Ending Balance	8,398	8,200
Commercial [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	2,563	1,706
Allowance for loan losses, Charge-offs	(8)	(5)
Allowance for loan losses, Recoveries	52	103
Allowance for loan losses, Provision for loan losses	(359)	36
Allowance for loan losses, Ending Balance	2,248	1,840
Agricultural [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	775	611
Allowance for loan losses, Charge-offs	0	0
Allowance for loan losses, Recoveries	0	0
Allowance for loan losses, Provision for loan losses	0	613
Allowance for loan losses, Ending Balance	775	1,224
Residential Real Estate [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	1,992	2,563
Allowance for loan losses, Charge-offs	(2)	(10)
Allowance for loan losses, Recoveries	27	56
Allowance for loan losses, Provision for loan losses	288	(127)
Allowance for loan losses, Ending Balance	2,305	2,482
Consumer Portfolio Segment [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	857	900
Allowance for loan losses, Charge-offs	(128)	(88)
Allowance for loan losses, Recoveries	48	60
Allowance for loan losses, Provision for loan losses	114	(77)
Allowance for loan losses, Ending Balance	891	795
Unallocated [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	2,188	1,920
Allowance for loan losses, Charge-offs	0	0
Allowance for loan losses, Recoveries	0	0
Allowance for loan losses, Provision for loan losses	(9)	(61)
Allowance for loan losses, Ending Balance	$ 2,179	$ 1,859

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

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

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of direct write-downs of financing receivables charged against the allowance.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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