Loans and ALLL (Summary of recorded investment in loans by segments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	$ 1,938	$ 2,130
Collectively evaluated for impairment, ALLL	6,437	5,570
Total, ALLL	8,375	7,700	$ 7,400
Individually evaluated for impairment, Loans	31,099	26,653
Collectively evaluated for impairment, Loans	1,097,608	1,064,866
Total	1,128,707	1,091,519
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	443	650
Collectively evaluated for impairment, ALLL	2,120	1,056
Total, ALLL	2,563	1,706	1,814
Individually evaluated for impairment, Loans	9,899	8,099
Collectively evaluated for impairment, Loans	649,630	626,660
Total	659,529	634,759
Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	132	0
Collectively evaluated for impairment, ALLL	643	611
Total, ALLL	775	611	884
Individually evaluated for impairment, Loans	14,298	10,598
Collectively evaluated for impairment, Loans	112,863	117,671
Total	127,161	128,269
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	1,363	1,480
Collectively evaluated for impairment, ALLL	629	1,083
Total, ALLL	1,992	2,563	2,664
Individually evaluated for impairment, Loans	6,893	7,939
Collectively evaluated for impairment, Loans	268,450	264,429
Total	275,343	272,368
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	0	0
Collectively evaluated for impairment, ALLL	857	900
Total, ALLL	857	900	624
Individually evaluated for impairment, Loans	9	17
Collectively evaluated for impairment, Loans	66,665	56,106
Total	66,674	56,123
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment, ALLL	0	0
Collectively evaluated for impairment, ALLL	2,188	1,920
Total, ALLL	$ 2,188	$ 1,920	$ 1,414

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

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