Derivative Financial Instruments - Schedule of Differences Between the Gains (Losses) on the Derivative and the Gains (Losses) on the Hedged Item (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	$ 15	$ 32	$ 53	$ 111
Gain (loss) on derivative recognized in OCI, net investment hedge	(265)	225	(22)	176
Other comprehensive income (loss), derivative, before reclassification and tax	(250)	257		287
Gain (loss) on hedges reclassified to income, cash flow hedge	(51)	(53)	94	(155)
Gain (loss) on hedges reclassified to income, net investment hedge	0	0	0	0
Other comprehensive income (loss), derivative, gain (loss), reclassification, before tax	(51)	(53)	94	(155)
Interest rate contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	15	(1)	(6)	(4)
Other comprehensive income (loss), derivative, before reclassification and tax			$ 31
Term of debt instrument			5 years
Interest rate contracts \| Net interest income
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, cash flow hedge	(51)	(53)	$ (160)	(156)
Foreign exchange contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	0	33	59	115
Gain (loss) on derivative recognized in OCI, net investment hedge	(265)	225	(22)	176
Foreign exchange contracts \| Net interest income
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, cash flow hedge	0	0	254	1
Foreign exchange contracts \| Gains (losses) related to investment securities, net
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, net investment hedge	$ 0	$ 0	$ 0	$ 0

Other Comprehensive Income (Loss), Derivative, Before Reclassification And Tax

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Other Comprehensive Income (Loss), Derivative, Gain (Loss), Reclassification, before Tax

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

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Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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-Section 45
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount, before tax and reclassification, of gain (loss) from derivative designated and qualifying as net investment hedge.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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-Section 50
-Paragraph 4CCC
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Amount, before tax, of reclassification from accumulated other comprehensive income (AOCI) for gain (loss) from derivative designated and qualifying as net investment hedge.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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