Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 1,164,821	$ 1,005,525
Net deferred loan (fees) costs	(176)	(575)
Overdraft deposits	128	82
Outstanding principal balance and the carrying amount of loan acquired [Abstract]
Outstanding principal balance	104,172	145,380
Carrying amount	96,487	135,254
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Outstanding principal balance	34,378	40,951
Carrying amount	28,669	33,885
Changes in the accretable discount on acquired loans [Abstract]
Balance at January 1	7,299	1,440	$ 2,046
Additions from merger with MainStreet	0	7,140	0
Accretion	(3,232)	(4,313)	(1,185)
Reclassification from nonaccretable difference	2,197	238	579
Other changes, net	(161)	2,794	0
Balance at December 31	6,103	7,299	$ 1,440
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	208,717	177,481
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	625,218	503,154
Commercial real estate | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	114,258	72,968
Commercial real estate | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	510,960	430,186
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	325,855	318,883
Residential real estate | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	215,104	220,434
Residential real estate | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	110,751	98,449
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 5,031	$ 6,007