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Loans and ALLL (Summary of recorded investment in loans by segments) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	$ 2,074		$ 2,130
Collectively evaluated for impairment, ALLL	6,026		5,570
Total, ALLL	8,100	$ 8,200	7,700	$ 7,700	$ 7,600	$ 7,400
Individually evaluated for impairment, Loans	31,354		26,653
Collectively evaluated for impairment, Loans	1,108,576		1,064,866
Total	1,139,930		1,091,519
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	481		650
Collectively evaluated for impairment, ALLL	1,540		1,056
Total, ALLL	2,021	2,197	1,706	2,169	1,978	1,814
Individually evaluated for impairment, Loans	8,858		8,099
Collectively evaluated for impairment, Loans	660,057		626,660
Total	668,915		634,759
Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	193		0
Collectively evaluated for impairment, ALLL	589		611
Total, ALLL	782	982	611	435	475	884
Individually evaluated for impairment, Loans	15,057		10,598
Collectively evaluated for impairment, Loans	114,175		117,671
Total	129,232		128,269
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	1,400		1,480
Collectively evaluated for impairment, ALLL	982		1,083
Total, ALLL	2,382	2,167	2,563	2,491	2,598	2,664
Individually evaluated for impairment, Loans	7,429		7,939
Collectively evaluated for impairment, Loans	269,475		264,429
Total	276,904		272,368
Total Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	0		0
Collectively evaluated for impairment, ALLL	902		900
Total, ALLL	902	882	900	633	583	624
Individually evaluated for impairment, Loans	10		17
Collectively evaluated for impairment, Loans	64,869		56,106
Total	64,879		56,123
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	0		0
Collectively evaluated for impairment, ALLL	2,013		1,920
Total, ALLL	$ 2,013	$ 1,972	$ 1,920	$ 1,972	$ 1,966	$ 1,414

X

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
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Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

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