Loans and Allowance for Loan Losses (Details 3) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Analysis of changes in the allowance for loan losses
Balance at beginning of period	$ 4,578	$ 4,868
Loan charge-offs	(1,213)	(137)
Recoveries	19	124
Net loan recoveries (charge-offs)	(1,194)	(13)
Provision charged to operations	500
Balance at end of period	3,884	4,855
Commercial
Analysis of changes in the allowance for loan losses
Balance at beginning of period	1,591	1,394
Loan charge-offs	(1,163)
Recoveries		108
Net loan recoveries (charge-offs)	(1,163)	108
Provision charged to operations	906	(256)
Balance at end of period	1,334	1,246
Commercial real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	2,702	3,072
Loan charge-offs		(93)
Net loan recoveries (charge-offs)		(93)
Provision charged to operations	(412)	247
Balance at end of period	2,290	3,226
Residential real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	117	163
Provision charged to operations	(24)	(21)
Balance at end of period	93	142
Consumer | Home equity
Analysis of changes in the allowance for loan losses
Balance at beginning of period	70	150
Recoveries	3	2
Net loan recoveries (charge-offs)	3	2
Provision charged to operations	(6)	(4)
Balance at end of period	67	148
Consumer | Other
Analysis of changes in the allowance for loan losses
Balance at beginning of period	98	89
Loan charge-offs	(50)	(44)
Recoveries	16	14
Net loan recoveries (charge-offs)	(34)	(30)
Provision charged to operations	36	34
Balance at end of period	$ 100	$ 93