Derivative Financial Instruments and Hedging Activities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	$ (647)	$ (521)	$ (392)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	784	818
Fair Value of Derivative Liabilities	1,992	2,141
Derivative, Collateral, Obligation to Return Cash	27	40
Derivative, Collateral, Right to Reclaim Cash	127	126
Derivative Asset, Not Offset, Policy Election Deduction	450	516
Derivative, Notional Amount	112,144	104,707
Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(85)	37	390
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	76,977	73,134
Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Net interest settlements and accruals excluded from the assessment of hedge effectiveness	(361)	(507)	(45)
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(220)	196	(1,875)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	182	(260)	1,893
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	16,194	12,119
Interest Rate Contract [Member] \| Currency Swap [Member] \| Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Net interest settlements and accruals excluded from the assessment of hedge effectiveness	(133)	(79)	(27)
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(134)	96	(111)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	108	(96)	113
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	268	(35)	50
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	9,716	10,276
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Affiliated Entity [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	5,300	5,900
Cross Currency Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(272)	127	$ (780)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	5,455	7,100
Cross Currency Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	3,802	2,078
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	305	465
Fair Value of Derivative Liabilities	845	1,036
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Affiliated Entity [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	115	46
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	66	106
Fair Value of Derivative Liabilities	645	633
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	271	59
Fair Value of Derivative Liabilities	117	116
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Cross Currency Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	133	119
Fair Value of Derivative Liabilities	246	252
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Cross Currency Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	9	69
Fair Value of Derivative Liabilities	$ 139	$ 104

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Income Effect of Derivative Financial Instruments [Abstract]

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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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Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and contract can be net settled by means outside contract or delivery of asset, subject to master netting arrangement or similar agreement and not elected or qualified to offset, deducted from derivative asset.

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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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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value, before 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 elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before 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 elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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