Loans and Allowance for Loan Losses (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Analysis of changes in the allowance for loan losses
Balance at beginning of period	$ 4,095	$ 4,830	$ 4,578	$ 4,868
Loan charge-offs	(49)	(164)	(1,289)	(344)
Recoveries	31	11	213	153
Net loan recoveries (charge-offs)	(18)	(153)	(1,076)	(191)
Provision charged to operations	75	100	650	100
Balance at end of period	4,152	4,777	4,152	4,777
Commercial
Analysis of changes in the allowance for loan losses
Balance at beginning of period	1,394	1,250	1,591	1,394
Loan charge-offs			(1,163)
Recoveries				108
Net loan recoveries (charge-offs)			(1,163)	108
Provision charged to operations	(123)	(33)	843	(285)
Balance at end of period	1,271	1,217	1,271	1,217
Commercial real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	2,457	3,313	2,702	3,072
Loan charge-offs		(125)		(225)
Recoveries	16		166
Net loan recoveries (charge-offs)	16	(125)	166	(225)
Provision charged to operations	128	110	(267)	451
Balance at end of period	2,601	3,298	2,601	3,298
Residential real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	80	113	117	163
Loan charge-offs				(13)
Recoveries			1	5
Net loan recoveries (charge-offs)			1	(8)
Provision charged to operations	25	(7)	(13)	(49)
Balance at end of period	105	106	105	106
Consumer | Home equity
Analysis of changes in the allowance for loan losses
Balance at beginning of period	66	60	70	150
Recoveries	1	3	5	7
Net loan recoveries (charge-offs)	1	3	5	7
Provision charged to operations	(1)	(1)	(9)	(95)
Balance at end of period	66	62	66	62
Consumer | Other
Analysis of changes in the allowance for loan losses
Balance at beginning of period	98	94	98	89
Loan charge-offs	(49)	(39)	(126)	(106)
Recoveries	14	8	41	33
Net loan recoveries (charge-offs)	(35)	(31)	(85)	(73)
Provision charged to operations	46	31	96	78
Balance at end of period	$ 109	$ 94	$ 109	$ 94