Derivatives - Net Gains (Losses) Relating to Free-Standing Derivative Instruments Used For Risk Management (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest Rate Contract | Forward Contracts | Loans Held For Sale | Mortgage banking net revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ (5)	$ (3)	$ (5)	$ (4)
Interest Rate Contract | Servicing Rights | Mortgage banking net revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	117	(16)	177	(65)
Foreign Exchange Contract | Forward Contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	(3)	3	(5)	5
Equity Contract | Swap | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ (22)	$ (10)	$ (52)	$ (49)