Derivative Financial Instruments - Notional Amounts and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Asset Derivatives
Notional Amount	$ 174,038	$ 44,294
Fair Value	3,659	554
Derivative Liability [Abstract]
Notional Amount	264,474	174,359
Fair Value	(1,495)	(354)
Derivatives designated as hedging instruments | Interest rate swaps
Asset Derivatives
Notional Amount	91,135	17,900
Fair Value	1,852	3
Derivative Liability [Abstract]
Notional Amount	181,274	73,235
Fair Value	(1,176)	(266)
Notional Amount	360,609	141,135
Derivatives designated as hedging instruments | Interest rate swaps associated with securities available-for-sale
Asset Derivatives
Notional Amount	50,000	0
Fair Value	1,075	0
Derivative Liability [Abstract]
Notional Amount	38,200	50,000
Fair Value	(196)	(8)
Derivatives not designated as hedging instruments | Interest Rate Lock Commitments
Asset Derivatives
Notional Amount	32,903	26,394
Fair Value	732	551
Derivatives not designated as hedging instruments | Forward contracts
Derivative Liability [Abstract]
Notional Amount	45,000	51,124
Fair Value	$ (123)	$ (80)