Derivatives and Hedging Activities - Schedule of Derivative Instrument Cash Flow Hedge Earning Recognized by Income Statement Location (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	$ (211)	$ (706)	$ (571)	$ (1,601)
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	(246)	(65)	(706)	22
Interest income – loans | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	(228)	(709)	(584)	(1,620)
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	(248)	(66)	(708)	16
Interest expense — Long-term debt | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	12	3	8	7
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	0	(1)	(1)	(3)
Investment banking and debt placement fees | Interest rate | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	5	0	5	12
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	$ 2	$ 2	$ 3	$ 9