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	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	$ 27	$ 1	$ 28
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	20	17	22
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	3	0	8
Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	1	(5)	(2)
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	3	(11)	0
Gain on mortgage and automotive loans, net | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	20	18	14
Other operating expenses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	3	0	8
Other income, net of losses | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	0	(1)	8
Other income, net of losses | Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	1	(5)	(2)
Other income, net of losses | Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain recognized in earnings	$ 3	$ (11)	$ 0