Derivatives and Hedging Activities - Effect of Fair Value and Cash Flow Hedges on Income (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense — Long-term debt	$ (146)	$ (54)	$ (256)	$ (168)
Interest income — Loans	1,134	882	2,894	2,659
Interest Income - securities	196	135	557	398
Investment banking and debt placement fees	154	235	466	614
Net gain (loss) on cash flow hedging relationships
Net Gains (Losses) Reclassified From OCI Into Income	(65)	77	22	250
Interest rate \| Interest expense – long-term debt \| Fair Value Hedging
Net gains (losses) on fair value hedging relationships
Recognized on hedged items	359	37	744	210
Recognized on derivatives designated as hedging instruments	(367)	(8)	(710)	(113)
Net income (expense) recognized on fair value hedges	(8)	29	34	97
Interest rate \| Interest expense – long-term debt \| Cash Flow Hedging
Net gain (loss) on cash flow hedging relationships
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	(1)	(1)	(3)	(3)
Net income (expense) recognized on cash flow hedges	(1)	(1)	(3)	(3)
Interest rate \| Interest income – loans \| Fair Value Hedging
Net gains (losses) on fair value hedging relationships
Recognized on hedged items	0	0	0	0
Recognized on derivatives designated as hedging instruments	0	0	0	0
Net income (expense) recognized on fair value hedges	0	0	0	0
Interest rate \| Interest income – loans \| Cash Flow Hedging
Net gain (loss) on cash flow hedging relationships
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	(66)	79	16	253
Net Gains (Losses) Reclassified From OCI Into Income	(66)	79	16	253
Net income (expense) recognized on cash flow hedges	(66)	79	16	253
Interest rate \| Interest Income - securities \| Fair Value Hedging
Net gains (losses) on fair value hedging relationships
Recognized on hedged items	(14)	(38)	(341)	(147)
Recognized on derivatives designated as hedging instruments	16	39	350	147
Net income (expense) recognized on fair value hedges	2	1	9	0
Interest rate \| Interest Income - securities \| Cash Flow Hedging
Net gain (loss) on cash flow hedging relationships
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	0	0	0	0
Net income (expense) recognized on cash flow hedges	0	0	0	0
Interest rate \| Investment banking and debt placement fees \| Fair Value Hedging
Net gains (losses) on fair value hedging relationships
Recognized on hedged items	0	0	0	0
Recognized on derivatives designated as hedging instruments	0	0	0	0
Net income (expense) recognized on fair value hedges	0	0	0	0
Interest rate \| Investment banking and debt placement fees \| Cash Flow Hedging
Net gain (loss) on cash flow hedging relationships
Net Gains (Losses) Reclassified From OCI Into Income	2	(1)	9	0
Net income (expense) recognized on cash flow hedges	$ 2	$ (1)	$ 9	$ 0

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Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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Interest and fee income generated by loans the Entity intends and has the ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (1) industrial and agricultural; (2) real estate; and (3) real estate construction loans; (4) trade financing; (5) lease financing; (6) home equity lines-of-credit; (7) automobile and other vehicle loans; and (8) credit card and other revolving-type loans. Also includes interest income for leases held by the Entity.

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Aggregate amount of interest paid or due on all long-term debt.

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