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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	$ 10	$ (8)	$ 7	$ (25)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	6	1	7	(6)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	5	(2)	2	(4)
Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	(1)	(7)	(2)	(15)
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	3	(1)	1	(8)
Other income, net of losses | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	3	2	6	2
Other income, net of losses | Other credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	(1)	(7)	(2)	(15)
Other operating expenses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments recognized in earnings	$ 5	$ (2)	$ 2	$ (4)