Derivative Instruments and Hedging Activities (Statement of Gains and Losses on Derivative Instruments Reported in Statement of Comprehensive Income) (Details) - Not designated as hedging instrument - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	$ 0	$ 10	$ (3)	$ 7
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	4	6	9	7
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	(1)	5	0	2
Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	0	(1)	(5)	(2)
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	(3)	0	(7)	0
Gain on mortgage and automotive loans, net | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	4	3	9	1
Other income, net of losses | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	0	3	0	6
Other income, net of losses | Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	0	(1)	(5)	(2)
Other income, net of losses | Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	(3)	0	(7)	0
Other operating expenses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) recognized in earnings	$ (1)	$ 5	$ 0	$ 2