Loans and Allowance for Credit Losses - Net Loans (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	$ 41,961	$ 36,631
Allowance for credit losses	(162)	(135)
Loans, net of allowance	41,799	36,496
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	24,874	23,065
Domestic | Collateralized loan obligations in loan form
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	50	150
Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	17,087	13,566
Non-U.S. | Collateralized loan obligations in loan form
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	7,818	6,369
Fund Finance | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	14,676	13,697
Fund Finance | Domestic | Private Equity Capital Call Finance Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	10,830	9,690
Fund Finance | Domestic | Real Money Funds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	7,440	6,630
Fund Finance | Domestic | Business Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	1,480	1,050
Fund Finance | Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	6,369	4,956
Leveraged loans | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	2,708	2,412
Leveraged loans | Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	1,142	1,194
Overdrafts | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	1,738	1,225
Overdrafts | Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	1,758	1,047
Other | Securities Finance Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	2,610	2,230
Other | Municipal Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	236	276
Other | Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross		5
Other | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	2,846	2,512
Commercial real estate | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	2,856	$ 3,069
Excluding Overdrafts | Floating Rate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	35,670
Excluding Overdrafts | Fixed Rate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, gross	$ 2,790