Financial Instruments With Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	$ 510,439	$ 405,889
Commercial real estate, construction, and land development
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	141,128	105,707
Commercial
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	140,835	129,541
SBA
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	32,480	6,614
Home equity
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	119,660	100,618
Mortgage loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	65,503	55,226
Lines of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	8,255	7,655
Standby letters of credit and bankers acceptances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, total loan commitments	$ 2,578	$ 528