Derivatives and Hedging Activities - Derivative Instrument Cash Flow Hedge Earning Recognized by Income Statement Location (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	$ (706)	$ 2	$ (1,601)	$ (133)
Net Gains (Losses) Reclassified From OCI Into Income	(65)	77	22	250
Interest income – loans | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	(709)	(2)	(1,620)	(144)
Net Gains (Losses) Reclassified From OCI Into Income	(66)	79	16	253
Interest expense — Long-term debt | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	3	0	7	2
Net Gains (Losses) Reclassified From OCI Into Income	(1)	(1)	(3)	(3)
Investment banking and debt placement fees | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	0	4	12	9
Net Gains (Losses) Reclassified From OCI Into Income		(1)
Investment banking and debt placement fees | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Reclassified From OCI Into Income	$ 2	$ (1)	$ 9	$ 0