Derivative Instruments - Gains (Losses) On Derivative Financial Instruments (Details) - Not designated as hedging instruments: - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	$ 1,744	$ (212)	$ 4,913	$ 3,046
Interest rate contracts | Included in interest income on loans
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	989	1,038	2,035	2,024
Interest rate lock commitments | Included in mortgage banking income
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	2,176	(238)	3,398	1,946
Forward commitments | Included in mortgage banking income
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	$ (1,421)	$ (1,012)	$ (520)	$ (924)