Loans and Allowance for Loan Losses (Details 3) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Analysis of changes in the allowance for loan losses
Balance at beginning of period	$ 4,868	$ 5,194
Loan charge-offs	(137)	(39)
Recoveries	124	25
Net loan recoveries (charge-offs)	(13)	(14)
Balance at end of period	4,855	5,180
Commercial
Analysis of changes in the allowance for loan losses
Balance at beginning of period	1,394	1,977
Recoveries	108
Net loan recoveries (charge-offs)	108
Provision charged to operations	(256)	8
Balance at end of period	1,246	1,985
Commercial real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	3,072	2,926
Loan charge-offs	(93)
Recoveries		1
Net loan recoveries (charge-offs)	(93)	1
Provision charged to operations	247	(24)
Balance at end of period	3,226	2,903
Residential real estate
Analysis of changes in the allowance for loan losses
Balance at beginning of period	163	153
Provision charged to operations	(21)	1
Balance at end of period	142	154
Consumer | Home equity
Analysis of changes in the allowance for loan losses
Balance at beginning of period	150	52
Recoveries	2	4
Net loan recoveries (charge-offs)	2	4
Provision charged to operations	(4)	(3)
Balance at end of period	148	53
Consumer | Other
Analysis of changes in the allowance for loan losses
Balance at beginning of period	89	86
Loan charge-offs	(44)	(39)
Recoveries	14	20
Net loan recoveries (charge-offs)	(30)	(19)
Provision charged to operations	34	18
Balance at end of period	$ 93	$ 85