Derivatives - Net Gains (Losses) Relating to Free-Standing Derivative Instruments Used For Risk Management (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 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	$ 11	$ 7	$ 6	$ 4
Interest Rate Contract | Servicing Rights | Mortgage banking net revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	130	(24)	308	(89)
Foreign Exchange Contract | Forward Contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	2	(1)	(3)	3
Equity Contract | Swap | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ (11)	$ (17)	$ (63)	$ (66)