Financial Instruments with Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments represent off-balance sheet credit risk	$ 90,659	$ 86,491
Future loan commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments represent off-balance sheet credit risk	4,998	3,805
Undisbursed construction loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments represent off-balance sheet credit risk	12,413	7,175
Undisbursed home equity lines of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments represent off-balance sheet credit risk	10,955	11,185
Undisbursed commercial and other line of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments represent off-balance sheet credit risk	59,969	60,897
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments represent off-balance sheet credit risk	$ 2,324	$ 3,429