Derivative Financial Instruments - Derivatives Not Designated as Hedges (Details) - Derivatives Not Designated as Hedging Instruments - Other noninterest income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest rate swaps
Impact on pretax earnings of derivatives not designated as hedges
Net Gains (Losses) on Derivatives		$ 227	$ 16	$ 631
Funding Swap (Visa Derivative)
Impact on pretax earnings of derivatives not designated as hedges
Net Gains (Losses) on Derivatives	$ (247)	4	(242)	(80)
Foreign exchange contracts
Impact on pretax earnings of derivatives not designated as hedges
Net Gains (Losses) on Derivatives	$ (1)	$ (30)	$ (1)	$ (92)