Loans - Components of Loans (Details) - USD ($) $ in Millions		Dec. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	[1]	$ 62,753	$ 58,987
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		41,051	39,957
Commercial loans | Real estate, including construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		6,612	7,087
Commercial loans | Business and corporate banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		15,431	15,724
Commercial loans | Global banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		9,995	10,725
Commercial loans | Other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		9,013	6,421
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		21,702	19,030
Consumer loans | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		21,035	18,341
Consumer loans | Home equity mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		393	389
Consumer loans | Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		195	199
Consumer loans | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		79	101
Consumer loans | Student loans held for investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, designated under fair value option		11	15
Affiliates | Commercial loans | Other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		5,449	2,618
Other | Commercial loans | Other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net		$ 3,564	$ 3,803

[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