Derivative Financial Instruments - Notional Amounts and Fair Value (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Asset Derivatives
Notional Amount	$ 95,418,000	$ 97,311,000
Fair Value	474,000	1,048,000
Derivative Liability [Abstract]
Notional Amount	123,235,000	0
Fair Value	(274,000)	0
Derivatives designated as hedging instruments | Interest rate swaps
Asset Derivatives
Notional Amount	17,900,000	0
Fair Value	3,000	0
Derivative Liability [Abstract]
Notional Amount	73,235,000	0
Fair Value	(266,000)	0
Notional Amount	141,135,000
Derivatives designated as hedging instruments | Interest rate swaps associated with securities available-for-sale
Derivative Liability [Abstract]
Notional Amount	50,000,000	0
Fair Value	(8,000)	0
Derivatives not designated as hedging instruments | IRLCs
Asset Derivatives
Notional Amount	26,394,000	36,311,000
Fair Value	551,000	610,000
Derivatives not designated as hedging instruments | Forward contracts
Asset Derivatives
Notional Amount	51,124,000	61,000,000
Fair Value	$ (80,000)	$ 438,000