Loans - Loans Serving as Collateral (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	$ 540,221	$ 421,632
Commercial real estate
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	311,024	224,703
Residential
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	220,815	187,524
Home Equity
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	$ 8,382	$ 9,405