Derivative Instruments and Hedging Activities - Effects of Fair Value and Cash Flow Hedge Accounting (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Interest and dividend income, securities	$ 615	$ 402
Interest and fee income, loans	8,723	6,367
Interest and dividend income, other	416	15
Deposits	(1,856)	(218)
Securitized debt obligations	(211)	(29)
Senior and subordinated notes	(489)	(131)
Non-interest income (loss)	199	343
Amortization expense (benefit)	(15)	(17)
Loss (net after-tax) recorded in AOCI related to derivatives designated as cash flow hedges expected to be reclassified to earnings over the next 12 months	765
Non interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains) on foreign exchange contracts reclassified from AOCI	8	13
Cash flow hedges \| Interest income - Investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Interest income - Loans
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	(262)	127
Cash flow hedges \| Interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	3	0
Cash flow hedges \| Interest expense - Deposits
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Interest expense - Securitized Debt Obligation
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Interest expense - Senior and Subordinated Debt
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Non interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Interest rate contracts \| Interest income - Investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Interest rate contracts \| Interest income - Loans
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	(262)	127
Cash flow hedges \| Interest rate contracts \| Interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Interest rate contracts \| Interest expense - Deposits
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Interest rate contracts \| Interest expense - Securitized Debt Obligation
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Interest rate contracts \| Interest expense - Senior and Subordinated Debt
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Interest rate contracts \| Non interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Foreign exchange contracts \| Interest income - Investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Foreign exchange contracts \| Interest income - Loans
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Foreign exchange contracts \| Interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	3	0
Cash flow hedges \| Foreign exchange contracts \| Interest expense - Deposits
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Foreign exchange contracts \| Interest expense - Securitized Debt Obligation
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Foreign exchange contracts \| Interest expense - Senior and Subordinated Debt
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Cash flow hedges \| Foreign exchange contracts \| Non interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from AOCI on derivatives, net of tax	0	0
Fair value hedges \| Interest income - Investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	15	(34)
Fair value hedges \| Interest income - Loans
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	0	0
Fair value hedges \| Interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	0	0
Fair value hedges \| Interest expense - Deposits
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	(80)	21
Fair value hedges \| Interest expense - Securitized Debt Obligation
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	(85)	25
Fair value hedges \| Interest expense - Senior and Subordinated Debt
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	(189)	77
Fair value hedges \| Non interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Net income (expense) recognized on fair value hedges	0	0
Fair value hedges \| Interest rate contracts \| Interest income - Investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	33	(8)
Gains (losses) recognized on derivatives	(49)	175
Gains (losses) recognized on hedged items	31	(201)
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts \| Interest income - Loans
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	0	0
Gains (losses) recognized on derivatives	0	0
Gains (losses) recognized on hedged items	0	0
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts \| Interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	0	0
Gains (losses) recognized on derivatives	0	0
Gains (losses) recognized on hedged items	0	0
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts \| Interest expense - Deposits
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	(78)	21
Gains (losses) recognized on derivatives	178	(115)
Gains (losses) recognized on hedged items	(180)	115
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts \| Interest expense - Securitized Debt Obligation
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	(84)	27
Gains (losses) recognized on derivatives	148	(305)
Gains (losses) recognized on hedged items	(149)	303
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts \| Interest expense - Senior and Subordinated Debt
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	(220)	38
Gains (losses) recognized on derivatives	387	(856)
Gains (losses) recognized on hedged items	(355)	896
Excluded component of fair value hedges	(1)	(1)
Fair value hedges \| Interest rate contracts \| Non interest income - Other
Derivative Instruments, Gain (Loss) [Line Items]
Interest recognized on derivatives	0	0
Gains (losses) recognized on derivatives	17	(38)
Gains (losses) recognized on hedged items	(17)	38
Excluded component of fair value hedges	$ 0	$ 0

Amortization of Basis Adjustment on Discontinued Hedges

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Total amount of gain (loss) derived from cash flow hedges recognized in earnings in the period

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The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

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

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