Loans and Allowance for Loan Losses (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Analysis of changes in the allowance for loan losses
Balance at beginning of period	$ 3,884	$ 4,855	$ 4,578	$ 4,868
Loan charge-offs	(27)	(43)	(1,240)	(180)
Recoveries	163	18	182	142
Net loan recoveries (charge-offs)	136	(25)	(1,058)	(38)
Provision charged to operations	75		575
Balance at end of period	4,095	4,830	4,095	4,830
Commercial
Analysis of changes in the allowance for loan losses
Balance at beginning of period	1,334	1,246	1,591	1,394
Loan charge-offs			(1,163)
Recoveries				108
Net loan recoveries (charge-offs)			(1,163)	108
Provision charged to operations	60	4	966	(252)
Balance at end of period	1,394	1,250	1,394	1,250
Commercial real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	2,290	3,226	2,702	3,072
Loan charge-offs		(7)		(100)
Recoveries	150		150
Net loan recoveries (charge-offs)	150	(7)	150	(100)
Provision charged to operations	17	94	(395)	341
Balance at end of period	2,457	3,313	2,457	3,313
Residential real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	93	142	117	163
Loan charge-offs		(13)		(13)
Recoveries	1	5	1	5
Net loan recoveries (charge-offs)	1	(8)	1	(8)
Provision charged to operations	(14)	(21)	(38)	(42)
Balance at end of period	80	113	80	113
Consumer | Home equity
Analysis of changes in the allowance for loan losses
Balance at beginning of period	67	148	70	150
Recoveries	1	2	4	4
Net loan recoveries (charge-offs)	1	2	4	4
Provision charged to operations	(2)	(90)	(8)	(94)
Balance at end of period	66	60	66	60
Consumer | Other
Analysis of changes in the allowance for loan losses
Balance at beginning of period	100	93	98	89
Loan charge-offs	(27)	(23)	(77)	(67)
Recoveries	11	11	27	25
Net loan recoveries (charge-offs)	(16)	(12)	(50)	(42)
Provision charged to operations	14	13	50	47
Balance at end of period	$ 98	$ 94	$ 98	$ 94