Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Derivative
Amount of variation margin payment applied to derivative asset contracts	$ 771	$ 1,100
Valuation adjustments related to the credit risk associated with counterparties of customer accommodation derivative contracts	20	42
Derivative liabilities	464	230
Amount of variation margin payment applied to derivative liability contracts	570	1,100
Gain or losses reclassified from AOCI into earnings associated with the discontinuance of cash flow hedges	0	0
Notional amount of the risk participations agreements	$ 3,780	3,396
Interest rate contracts
Derivative
Maximum length of time of hedging exposure	37 months
Deferred gains, net of tax, on cash flow hedges recorded in accumulated other comprehensive income	$ 353	718
Net deferred gains or losses, net of tax, recorded in AOCI are expected to be reclassified into earnings	212
Interest rate contracts | Credit Risk
Derivative
Fair value of risk participation agreements	$ 8	8
Weighted-average remaining life	3 years 9 months 18 days
Total collateral
Derivative
Derivative assets	$ 1,100	1,000
Derivative liabilities	$ 1,300	$ 463