Derivative Instruments - Gains (Losses) On Derivative Financial Instruments (Details) - Not designated as hedging instruments: - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	$ 4,032	$ 2,144	$ 8,945	$ 5,190
Interest rate contracts | Included in interest income on loans
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	950	1,042	2,985	3,066
Interest rate lock commitments | Included in mortgage banking income
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	(444)	(1,737)	2,954	209
Forward commitments | Included in mortgage banking income
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	$ 3,526	$ 2,839	$ 3,006	$ 1,915