Derivatives and Hedging Activities - Schedule of Effect of Fair Value and Cash Flow Hedges on Income (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense — Long-term debt	$ (332)	$ (349)	$ (660)	$ (624)
Interest income – loans	1,524	1,576	3,062	3,052
Interest Income - securities	259	194	491	388
Investment banking and debt placement fees	126	120	296	265
Interest expense - deposits	(817)	(531)	(1,599)	(881)
Other income	11	4	17	4
Net gain (loss) on cash flow hedging relationships
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	(200)	(246)	(415)	(461)
Interest rate \| Interest expense – long-term debt \| Fair Value Hedging
Net gains (losses) on fair value hedging relationships
Recognized on hedged items	7	377	135	223
Recognized on derivatives designated as hedging instruments	(80)	(427)	(280)	(320)
Net income (expense) recognized on fair value hedges	(73)	(50)	(145)	(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)	(1)	(1)
Net income (expense) recognized on cash flow hedges	(1)	(1)	(1)	(1)
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	(199)	(245)	(415)	(460)
Net income (expense) recognized on cash flow hedges	(199)	(215)	(415)	(460)
Interest rate \| Interest Income - securities \| Fair Value Hedging
Net gains (losses) on fair value hedging relationships
Recognized on hedged items	(22)	(24)	(173)	(18)
Recognized on derivatives designated as hedging instruments	56	32	238	30
Net income (expense) recognized on fair value hedges	34	8	65	12
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
Realized gains (losses) (pre-tax) reclassified from AOCI into net income	0	0	1	0
Net income (expense) recognized on cash flow hedges	$ 0	$ 0	$ 1	$ 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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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 expense on all deposits.

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