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	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	$ 59	$ 37	$ 79	$ (207)
Gain (loss) on derivative recognized in OCI, net investment hedge	(8)	264	(49)	328
Other comprehensive income (loss), derivative, before reclassification and tax	51	301	30	121
Gain (loss) on hedges reclassified to income, cash flow hedge	(52)	9	(102)	31
Other comprehensive income (loss), derivative, gain (loss), reclassification, before tax	(52)	9	(102)	31
Gain (loss) on hedges reclassified to income, net investment hedge	0	0	$ 0	0
Floating-rate loans
Derivative [Line Items]
Term of debt instrument			5 years
Interest rate contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	(6)	(92)	$ (3)	(383)
Interest rate contracts \| Net interest income
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, cash flow hedge	(52)	6	(103)	25
Foreign exchange contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	65	129	82	176
Gain (loss) on derivative recognized in OCI, net investment hedge	(8)	264	(49)	328
Foreign exchange contracts \| Net interest income
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, cash flow hedge	0	3	1	6
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

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