Loans and ALLL (Summary of recorded investment in loans by segments) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	$ 1,114	$ 1,938
Collectively evaluated for impairment, ALLL	6,825	6,437
Total, ALLL	7,939	8,375	$ 7,700
Individually evaluated for impairment, Loans	28,191	31,099
Collectively evaluated for impairment, Loans	1,158,379	1,097,608
Total	1,186,570	1,128,707
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	15	443
Collectively evaluated for impairment, ALLL	1,899	2,120
Total, ALLL	1,914	2,563	1,706
Individually evaluated for impairment, Loans	7,865	9,899
Collectively evaluated for impairment, Loans	693,076	649,630
Total	700,941	659,529
Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	26	132
Collectively evaluated for impairment, ALLL	608	643
Total, ALLL	634	775	611
Individually evaluated for impairment, Loans	14,840	14,298
Collectively evaluated for impairment, Loans	102,080	112,863
Total	116,920	127,161
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	1,073	1,363
Collectively evaluated for impairment, ALLL	974	629
Total, ALLL	2,047	1,992	2,563
Individually evaluated for impairment, Loans	5,486	6,893
Collectively evaluated for impairment, Loans	293,083	268,450
Total	298,569	275,343
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	0	0
Collectively evaluated for impairment, ALLL	922	857
Total, ALLL	922	857	900
Individually evaluated for impairment, Loans	0	9
Collectively evaluated for impairment, Loans	70,140	66,665
Total	70,140	66,674
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	0	0
Collectively evaluated for impairment, ALLL	2,422	2,188
Total, ALLL	$ 2,422	$ 2,188	$ 1,920

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

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