Derivative Financial Instruments and Hedging Activities - Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Notional	$ 140,562	$ 142,212
Fair Value of Assets	1,968	2,302
Fair Value of Liabilities	2,907	3,392
Fair value of assets (liabilities) available for offset	1,200	1,300
Other Liabilities
Derivatives, Fair Value [Line Items]
Collateral held for netting against asset positions	480	553
Other Assets
Derivatives, Fair Value [Line Items]
Collateral available for netting against liability positions	1,200	1,500
Derivatives designated as hedges \| Fair value hedges \| Interest rate swaps \| Level 2
Derivatives, Fair Value [Line Items]
Notional	16,559	19,950
Fair Value of Assets	8	0
Fair Value of Liabilities	334	821
Derivatives designated as hedges \| Cash flow hedges \| Interest rate swaps \| Level 2
Derivatives, Fair Value [Line Items]
Notional	1,637	1,434
Fair Value of Assets	33	34
Fair Value of Liabilities	3	1
Derivatives designated as hedges \| Cash flow hedges \| Foreign currency swaps \| Level 2
Derivatives, Fair Value [Line Items]
Notional	8,013	6,852
Fair Value of Assets	3	0
Fair Value of Liabilities	497	586
Derivatives not designated as hedges \| Interest rate contracts \| Level 2
Derivatives, Fair Value [Line Items]
Notional	114,353	113,975
Fair Value of Assets	1,924	2,268
Fair Value of Liabilities	$ 2,073	$ 1,984

Derivative Assets (Liabilities), Net, Fair Value, Amount Not Offset Against Collateral

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Nominal or face amount used to calculate payments on the derivative asset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Amount of right to receive cash collateral under master netting arrangements offset against derivative liabilities.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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