Derivative Financial Instruments and Hedging Activities - Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Fair value of assets (liabilities) available for offset	$ 778	$ 505
Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	136,674	133,971
Fair Value of Assets	1,353	1,017
Collateral available for netting against liability positions	432	45
Other Liabilities
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	1,368	691
Collateral held for netting against asset positions	323	376
Designated as Hedging Instrument \| Fair Value Hedging \| Other Assets \| Interest Rate Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	19,310	15,058
Fair Value of Assets	11	74
Designated as Hedging Instrument \| Fair Value Hedging \| Other Assets \| Foreign Currency Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	0	682
Fair Value of Assets	0	0
Designated as Hedging Instrument \| Fair Value Hedging \| Other Liabilities \| Interest Rate Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	345	88
Designated as Hedging Instrument \| Fair Value Hedging \| Other Liabilities \| Foreign Currency Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	0	59
Designated as Hedging Instrument \| Cash Flow Hedging \| Other Assets \| Interest Rate Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	709	611
Fair Value of Assets	17	12
Designated as Hedging Instrument \| Cash Flow Hedging \| Other Assets \| Foreign Currency Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	7,945	7,419
Fair Value of Assets	79	85
Designated as Hedging Instrument \| Cash Flow Hedging \| Other Liabilities \| Interest Rate Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	4	4
Designated as Hedging Instrument \| Cash Flow Hedging \| Other Liabilities \| Foreign Currency Swaps \| Level 2
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	221	201
Not Designated as Hedging Instrument \| Other Assets \| Interest Rate Contracts \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	108,709	110,053
Fair Value of Assets	1,245	846
Not Designated as Hedging Instrument \| Other Assets \| Foreign Currency Contract \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, Notional amount	0	148
Fair Value of Assets	0	0
Not Designated as Hedging Instrument \| Other Liabilities \| Interest Rate Contracts \| Level 2
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	797	339
Not Designated as Hedging Instrument \| Other Liabilities \| Foreign Currency Contract \| Level 2
Derivatives, Fair Value [Line Items]
Fair Value of Liabilities	$ 0	$ 0

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

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- Definition

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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- Definition

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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