Loans and Allowance for Loan Losses (Details 6) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Summary of nonperforming assets
Nonaccruing troubled debt restructurings	$ 2,194	$ 2,673
Total nonaccrual loans, including nonaccruing TDRs	5,966	7,301
Other real estate owned	117	242
Total nonperforming assets	$ 6,083	$ 7,543
Nonperforming assets as a percentage of:
Total assets	0.33%	0.46%
Gross loans	0.38%	0.54%
Total loans over 90 days past due	$ 282	$ 2,027
Loans over 90 days past due and still accruing
Accruing troubled debt restructurings	6,699	5,145
Commercial [Member] | Construction [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings
Commercial [Member] | Owner occupied RE [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings
Commercial [Member] | Non-owner occupied RE [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings	1,680	1,581
Commercial [Member] | Business [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings	89	910
Consumer [Member] | Real estate [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings	1,153	992
Consumer [Member] | Home equity [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings	850	1,144
Consumer [Member] | Construction [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings
Consumer [Member] | Other [Member]
Summary of nonperforming assets
Nonaccruing troubled debt restructurings		$ 1