Loans - Impaired Loans by Average Recorded Investment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	$ 6,802	$ 6,062	$ 7,346	$ 8,483
Commercial real estate - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	67	67	151	23
Commercial real estate - nonowner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	334	0	779	2,423
Real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	939	1,003	953	1,022
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	952	23	1,189	45
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	4,508	4,969	4,273	4,970
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	$ 2	$ 0	$ 1	$ 0