Derivative Instruments and Hedging Activities (Derivatives Not Designated as Hedges) (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Other Noninterest Income/(Expense)	$ 13	$ 19	$ 28	$ 28
Customer-facing interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other Noninterest Income/(Expense)	6	10	12	11
Other interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other Noninterest Income/(Expense)	0	3	1	3
Foreign exchange derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other Noninterest Income/(Expense)	7	7	15	15
Purchased credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other Noninterest Income/(Expense)	$ 0	$ (1)	$ 0	$ (1)