Financial Derivatives (Gains (Losses) on Derivatives Not Designated As Hedging Instruments under GAAP) (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 [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	$ 75	$ 245	$ (2)	$ 75
Mortgage Banking | Interest Rate Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	(190)	216	(455)	(106)
Customer Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	49	58	190	162
Customer Contracts | Interest Rate Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	69	15	166	97
Customer Contracts | Foreign exchange contracts and other
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	(20)	43	24	65
Other Risk Management Activity | Foreign exchange contracts and other
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	$ 216	$ (29)	$ 263	$ 19