Loans - Additional Information (Detail) - USD ($)		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred origination costs (fees)		$ 31,000,000		$ 40,000,000
Net unamortized premium (discount)		3,000,000		5,000,000
Interest income that was recorded on nonaccrual loans and included in interest income during the period		3,000,000	$ 15,000,000
Commercial loans removed from TDR classification		0	$ 0
Loans	[1]	58,610,000,000		55,864,000,000
Interest only residential mortgage loans		3,779,000,000		3,739,000,000
Consumer loans:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		$ 16,156,000,000		16,068,000,000
Weighted average rate of reduction		1.09%	1.97%
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent		$ 0	$ 3,000,000
Threshold period for troubled debt restructuring status		60 days	60 days
Consumer loans: | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		$ 197,000,000		214,000,000
Loans		15,573,000,000		15,469,000,000
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent		0	$ 3,000,000
Commercial loans:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		260,000,000		347,000,000
Loans		42,454,000,000		$ 39,796,000,000
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent		$ 0	$ 0
Threshold period for troubled debt restructuring status		90 days	90 days

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2022 and December 31, 2021. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. March 31, 2022December 31, 2021(in millions)AssetsLoans$128 $46 Other assets51 55 Total assets$179 $101 LiabilitiesInterest, taxes and other liabilities$31 $9 Total liabilities$31 $9