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, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	$ (230)	$ 75	$ (142)	$ (2)
Mortgage Banking | Interest Rate Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	(184)	(190)	(77)	(455)
Customer Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	91	49	149	190
Customer Contracts | Interest Rate Contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	33	69	35	166
Customer Contracts | Foreign exchange contracts and other
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	58	(20)	114	24
Other Risk Management Activity | Foreign exchange contracts and other
Derivative [Line Items]
Derivative instruments not designated as hedging instruments gain (loss), net	$ (137)	$ 216	$ (214)	$ 263