Derivative Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Derivative
Derivative, notional amount	$ 1,700,000,000		$ 1,700,000,000		$ 1,300,000,000
Amount of variation margin payment applied to derivative asset contracts	698,000,000		698,000,000		1,000,000,000
Valuation adjustments related to the credit risk associated with counterparties of customer accommodation derivative contracts	4,000,000		4,000,000		9,000,000
Collateral held for derivative liabilities	982,000,000		982,000,000		913,000,000
Amount of variation margin payment applied to derivative liability contracts	1,900,000,000		1,900,000,000		1,000,000,000
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	3,897,000,000		3,897,000,000		3,710,000,000
Interest rate contracts | Credit Risk
Derivative
Fair value of risk participation agreements	7,000,000		$ 7,000,000		7,000,000
Weighted-average remaining life			3 years
Cash Flow Hedging | Interest rate contracts
Derivative
Maximum length of time of hedging exposure			100 months
Deferred gain (loss), net of tax, on cash flow hedges recorded in accumulated other comprehensive income	977,000,000		$ 977,000,000		$ 498,000,000
Net deferred gain (loss), net of tax, recorded in AOCI are expected to be reclassified into earnings	$ 309,000,000		$ 309,000,000