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Loans and Allowance for Loan Losses (Details 4) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Commercial & industrial [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment	$ 948		$ 605
With no related allowance recorded, Unpaid Principal Balance	1,233	$ 32	832
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	949	32	405
With no related allowance recorded, Interest Income Recognized	25		23
With a specific allowance recorded, Recorded Investment			125
With a specific allowance recorded, Unpaid Principal Balance			125
With a specific allowance recorded, Related Allowance			61
With a specific allowance recorded, Average Recorded Investment			127
With a specific allowance recorded, Interest Income Recognized			21
Total Recorded Investment	948		730
Total Unpaid Principal Balance	1,223	32	957
Total Related Allowance			61
Total Average Recorded Investment	949	32	532
Total Interest Income Recognized	25		44
Commercial real estate - owner occupied [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment
With no related allowance recorded, Unpaid Principal Balance
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment
With no related allowance recorded, Interest Income Recognized
With a specific allowance recorded, Recorded Investment
With a specific allowance recorded, Unpaid Principal Balance
With a specific allowance recorded, Related Allowance
With a specific allowance recorded, Average Recorded Investment
With a specific allowance recorded, Interest Income Recognized
Total Recorded Investment
Total Unpaid Principal Balance
Total Related Allowance
Total Average Recorded Investment
Total Interest Income Recognized
Commercial real estate - nonowner occupied [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment	212		218
With no related allowance recorded, Unpaid Principal Balance	212	506	218
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	259	480	260
With no related allowance recorded, Interest Income Recognized	7		17
With a specific allowance recorded, Recorded Investment
With a specific allowance recorded, Unpaid Principal Balance
With a specific allowance recorded, Related Allowance
With a specific allowance recorded, Average Recorded Investment
With a specific allowance recorded, Interest Income Recognized
Total Recorded Investment	212		218
Total Unpaid Principal Balance	212	506	218
Total Related Allowance
Total Average Recorded Investment	259	480	260
Total Interest Income Recognized	7		17
Agricultural [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment
With no related allowance recorded, Unpaid Principal Balance
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment
With no related allowance recorded, Interest Income Recognized
With a specific allowance recorded, Recorded Investment
With a specific allowance recorded, Unpaid Principal Balance
With a specific allowance recorded, Related Allowance
With a specific allowance recorded, Average Recorded Investment
With a specific allowance recorded, Interest Income Recognized
Total Recorded Investment
Total Unpaid Principal Balance
Total Related Allowance
Total Average Recorded Investment
Total Interest Income Recognized
Residential Real Estate [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment	1,337		1,376
With no related allowance recorded, Unpaid Principal Balance	1,380	1,485	1,419
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	1,608	1,442	1,656
With no related allowance recorded, Interest Income Recognized	24		90
With a specific allowance recorded, Recorded Investment	971		933
With a specific allowance recorded, Unpaid Principal Balance	971	1,160	959
With a specific allowance recorded, Related Allowance	89		76
With a specific allowance recorded, Average Recorded Investment	1,003	1,141	993
With a specific allowance recorded, Interest Income Recognized	12		35
Total Recorded Investment	2,308		2,309
Total Unpaid Principal Balance	2,351	2,645	2,378
Total Related Allowance	89		76
Total Average Recorded Investment	2,611	2,583	2,649
Total Interest Income Recognized	36		125
HELOC [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment	18		20
With no related allowance recorded, Unpaid Principal Balance	18		20
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	20		21
With no related allowance recorded, Interest Income Recognized			1
With a specific allowance recorded, Recorded Investment
With a specific allowance recorded, Unpaid Principal Balance
With a specific allowance recorded, Related Allowance
With a specific allowance recorded, Average Recorded Investment
With a specific allowance recorded, Interest Income Recognized
Total Recorded Investment	18		20
Total Unpaid Principal Balance	18		20
Total Related Allowance
Total Average Recorded Investment	20		21
Total Interest Income Recognized			1
Consumer [Member]
Summary of Impaired loan activity
With no related allowance recorded, Recorded Investment
With no related allowance recorded, Unpaid Principal Balance
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment
With no related allowance recorded, Interest Income Recognized
With a specific allowance recorded, Recorded Investment	20		7
With a specific allowance recorded, Unpaid Principal Balance	20	10	7
With a specific allowance recorded, Related Allowance	1		1
With a specific allowance recorded, Average Recorded Investment	21	10	8
With a specific allowance recorded, Interest Income Recognized			1
Total Recorded Investment	20		7
Total Unpaid Principal Balance	20	10	7
Total Related Allowance	1		1
Total Average Recorded Investment	21	$ 10	8
Total Interest Income Recognized			$ 1