Loans - Narrative (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred origination costs (fees)		$ 22		$ 22		$ 14
Net unamortized premium (discount)		(8)		(8)		(10)
Interest income that was recorded on nonaccrual loans and included in interest income during the period		2	$ 2	3	$ 5
Loans, net	[1]	57,945		57,945		59,380
Interest only residential mortgage loans		4,215		4,215		4,063
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified, subsequently default		0		0
Loans, net		252		252		143
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		18,134		18,134		17,563
Weighted average rate of reduction			0.14%		0.24%
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent			$ 0		$ 0
Threshold period for troubled debt restructuring status					60 days
Consumer loans | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		96		96		111
Consumer loans | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		267		267		249
Loans, net		17,452		17,452		16,838
Consumer loans | Residential mortgages | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		88		88		105
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		299		299		130
Additional commitments for loans modified		40		40
Loans, net		39,811		39,811		41,817
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
Commercial loans | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		$ 156		$ 156		$ 32

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at June 30, 2023 and December 31, 2022. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. June 30, 2023December 31, 2022(in millions)AssetsLoans, net$186 $162 Other assets40 44 Total assets$226 $206 LiabilitiesInterest, taxes and other liabilities$35 $22 Total liabilities$35 $22