Loans - Components of Loans (Details) - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	[1]	$ 58,610	$ 55,864
Commercial loans:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		42,454	39,796
Commercial loans: | Real Estate, including Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		8,020	8,234
Commercial loans: | Business and corporate banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		15,305	13,958
Commercial loans: | Global banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		11,948	11,109
Commercial loans: | Other commercial:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		7,181	6,495
Consumer loans:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		16,156	16,068
Consumer loans: | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		15,573	15,469
Consumer loans: | Home equity mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		306	325
Consumer loans: | Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		205	204
Consumer loans: | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		72	70
Affiliates | Commercial loans: | Other commercial:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		3,438	2,793
Other | Commercial loans: | Other commercial:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		$ 3,743	$ 3,702

[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