Loans - Narrative (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum percentage of loans outstanding to executive officers and directors as compared to total equity		5.00%	5.00%
Net deferred origination costs (fees)		$ 32	$ 17
Net unamortized premium (discount)		(10)	(13)
Interest income that was recorded on nonaccrual loans and included in interest income during the period		27	5	$ 10
Loans modified		443	628
Loans, net	[1]	62,753	58,987
Interest only residential mortgage loans		4,650	4,392
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		313	309
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified		5	12
Loans, net		21,702	19,030
Consumer loans | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified, subsequently default		0	0
Loans, net		112	99
Consumer loans | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		282	278
Loans modified		5	12
Loans, net		21,035	18,341
Consumer loans | Residential mortgages | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		105	91
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans		524	618
Loans modified		438	616
Additional commitments for loans modified		25	85
Loans, net		41,051	39,957
Commercial loans | 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified, subsequently default		30	166
Loans, net		$ 201	$ 210

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2024 and 2023. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 27, "Variable Interest Entities," for additional information. At December 31,20242023(in millions)AssetsOther assets$11 $23 Total assets$11 $23 LiabilitiesInterest, taxes and other liabilities$4 $17 Total liabilities$4 $17