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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	$ 37	$ 17	$ (207)	$ 37
Gain (loss) on derivative recognized in OCI, net investment hedge	264	(24)	328	111
Amount of Gain or (Loss) Recognized in Other Comprehensive Income on Derivative	301	(7)	121	148
Gain (loss) on hedges reclassified to income, cash flow hedge	9	25	31	46
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income into Income	9	25	31	46
Gain (loss) on hedges reclassified to income, net investment hedge	0	0	$ 0	0
Floating-rate loans
Derivative [Line Items]
Term of debt instrument			4 years 3 months 18 days
Interest rate contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	(92)	10	$ (383)	(6)
Interest rate contracts \| Net interest income
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, cash flow hedge	6	22	25	40
Foreign exchange contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI, cash flow hedge	129	7	176	43
Gain (loss) on derivative recognized in OCI, net investment hedge	264	(24)	328	111
Foreign exchange contracts \| Net interest income
Derivative [Line Items]
Gain (loss) on hedges reclassified to income, cash flow hedge	3	3	6	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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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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