Derivative Financial Instruments - Amounts Related to Derivative Instruments Not Designated as Hedges (Details) - Not designated as hedges - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	$ 114	$ 32	$ 29
Client-related and other risk management | Interest rate contracts | Investment banking and trading income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	76	40	50
Client-related and other risk management | Foreign exchange contracts | Investment banking and trading income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	(13)	21	1
Client-related and other risk management | Equity contracts | Investment banking and trading income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	(3)	0	0
Client-related and other risk management | Credit Contract | Investment banking and trading income and other income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	(25)	0	0
Mortgage banking | Interest rate contracts | Residential mortgage income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	(61)	36	(23)
Mortgage banking | Interest rate contracts | Commercial real estate related income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	(4)	0	1
MSRs | Interest rate contracts | Residential mortgage income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	137	(62)	0
MSRs | Interest rate contracts | Commercial real estate related income
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax Gain (Loss) Recognized in Income	$ 7	$ (3)	$ 0