Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Derivative
Amount of variation margin payment applied to derivative asset contracts	$ 956		$ 956		$ 771
Valuation adjustments related to the credit risk associated with counterparties of customer accommodation derivative contracts	11		11		20
Derivatives	1,596		1,596		464
Amount of variation margin payment applied to derivative liability contracts	518		518		570
Gain or losses reclassified from AOCI into earnings associated with the discontinuance of cash flow hedges	0	$ 0	0	$ 0
Notional amount of the risk participations agreements	3,721		3,721		3,780
Interest rate contracts | Credit Risk
Derivative
Fair value of risk participation agreements	8		$ 8		8
Weighted-average remaining life			3 years 3 months 18 days
Cash Flow Hedging | Interest rate contracts
Derivative
Maximum length of time of hedging exposure			114 months
Deferred gain (loss), net of tax, on cash flow hedges recorded in accumulated other comprehensive income	(63)		$ (63)		353
Net deferred gain (loss), net of tax, recorded in AOCI are expected to be reclassified into earnings	(77)		(77)
Total collateral
Derivative
Derivatives	1,300		1,300		1,100
Derivatives	$ 2,200		$ 2,200		$ 1,300