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		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	$ 20	$ (4)	$ 27	$ (29)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	11	0	18	(6)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	9	3	11	(1)
Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	0	(7)	(2)	(22)
Gain (loss) on mortgage and automotive loans, net | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	7	(4)	8	(12)
Other income, net of losses | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	4	4	10	6
Other income, net of losses | Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	0	(7)	(2)	(22)
Other operating expenses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	$ 9	$ 3	$ 11	$ (1)