Loans and ALLL (Summary of changes in ALLL by segments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	$ 8,398	$ 8,200	$ 8,375	$ 7,700
Allowance for loan losses, Charge-offs	(333)	(566)	(471)	(669)
Allowance for loan losses, Recoveries	151	238	278	457
Allowance for loan losses, Provision for loan losses	(179)	328	(145)	712
Allowance for loan losses, Ending Balance	8,037	8,200	8,037	8,200
Commercial [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	2,248	1,840	2,563	1,706
Allowance for loan losses, Charge-offs	(164)	(489)	(172)	(494)
Allowance for loan losses, Recoveries	22	101	74	204
Allowance for loan losses, Provision for loan losses	(26)	745	(385)	781
Allowance for loan losses, Ending Balance	2,080	2,197	2,080	2,197
Agricultural [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	775	1,224	775	611
Allowance for loan losses, Charge-offs	0	0	0	0
Allowance for loan losses, Recoveries	0	0	0	0
Allowance for loan losses, Provision for loan losses	(163)	(242)	(163)	371
Allowance for loan losses, Ending Balance	612	982	612	982
Residential Real Estate [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	2,305	2,482	1,992	2,563
Allowance for loan losses, Charge-offs	(94)	(29)	(96)	(39)
Allowance for loan losses, Recoveries	91	69	118	125
Allowance for loan losses, Provision for loan losses	(420)	(355)	(132)	(482)
Allowance for loan losses, Ending Balance	1,882	2,167	1,882	2,167
Consumer Portfolio Segment [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	891	795	857	900
Allowance for loan losses, Charge-offs	(75)	(48)	(203)	(136)
Allowance for loan losses, Recoveries	38	68	86	128
Allowance for loan losses, Provision for loan losses	73	67	187	(10)
Allowance for loan losses, Ending Balance	927	882	927	882
Unallocated [Member]
Summary of changes in the ALLL and the recorded investment in loans by segments
Allowance for loan losses, Beginning Balance	2,179	1,859	2,188	1,920
Allowance for loan losses, Charge-offs	0	0	0	0
Allowance for loan losses, Recoveries	0	0	0	0
Allowance for loan losses, Provision for loan losses	357	113	348	52
Allowance for loan losses, Ending Balance	$ 2,536	$ 1,972	$ 2,536	$ 1,972

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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- Definition

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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