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		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	$ 127	$ (47)	$ 125	$ 28
Mortgage Banking | Interest Rate Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	(245)	6	(700)	(100)
Customer Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	63	19	253	181
Customer Contracts | Interest Rate Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	65	(4)	231	93
Customer Contracts | Foreign exchange contracts and other
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	(2)	23	22	88
Other Risk Management Activity | Foreign exchange contracts and other
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	$ 309	$ (72)	$ 572	$ (53)