Derivatives and Hedging Activities - Schedule of Pre-Tax Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	$ 11	$ 9	$ 41	$ 54
Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	15	11	42	31
Foreign exchange
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	8	13	35	39
Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	1	4	5	9
Credit
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(14)	(22)	(33)	(35)
Other
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	1	3	(8)	10
Corporate services income
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	24	25	76	76
Corporate services income | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	15	8	36	27
Corporate services income | Foreign exchange
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	8	13	35	39
Corporate services income | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	1	4	5	9
Corporate services income | Credit
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	1
Corporate services income | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Consumer mortgage income
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(1)	0	(1)	1
Consumer mortgage income | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Consumer mortgage income | Foreign exchange
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Consumer mortgage income | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Consumer mortgage income | Credit
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Consumer mortgage income | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(1)	0	(1)	1
Other income
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(12)	(16)	(34)	(23)
Other income | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	3	6	4
Other income | Foreign exchange
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Other income | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0	0
Other income | Credit
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(14)	(22)	(33)	(36)
Other income | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	$ 2	$ 3	$ (7)	$ 9