Derivative Instruments and Hedging Activities - Schedule of Statement of Gains and Losses on Derivative Instruments Reported in Statement of Comprehensive Income (Details) - Total derivatives not designated as accounting hedges - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	$ 7	$ 0	$ 21	$ (3)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	6	3	16	12
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	(1)	1	1	1
Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	1	0	1	(5)
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	1	(4)	3	(11)
Gain on mortgage and automotive loans, net | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	6	4	16	13
Other operating expenses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	(1)	1	1	1
Other income, net of losses | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	0	(1)	0	(1)
Other income, net of losses | Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	1	0	1	(5)
Other income, net of losses | Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	$ 1	$ (4)	$ 3	$ (11)