Loans - Narrative (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding to executive officers and director as a percent of shareholders equity, maximum		5.00%	5.00%
Net deferred origination costs (fees)		$ 17	$ 14
Net unamortized premium (discount)		(13)	(10)
Interest income that was recorded on nonaccrual loans and included in interest income during the period		5	10	$ 34
Loans, net	[1]	58,987	59,380
Interest only residential mortgage loans		4,392	4,063
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		309	143
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		19,030	$ 17,563
Weighted average rate of reduction			0.25%	2.08%
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent			$ 0	$ 5
Threshold period for troubled debt restructuring status			60 days	60 days
Consumer loans | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified, subsequently default		0
Loans, net		99	$ 111
Consumer loans | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		278	249
Loans, net		18,341	16,838
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent			0	$ 5
Consumer loans | Residential mortgages | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		91	105
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		618	130
Additional commitments for loans modified		85
Loans, net		39,957	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	90 days
Commercial loans | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified, subsequently default		166
Loans, net		$ 210	$ 32

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2023 and 2022. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 27, "Variable Interest Entities," for additional information. At December 31,20232022(in millions)AssetsLoans, net$— $162 Other assets23 44 Total assets$23 $206 LiabilitiesInterest, taxes and other liabilities$17 $22 Total liabilities$17 $22