Loans and Allowance for Credit Losses - Net Loans (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 49,190	$ 46,782
Allowance for credit losses	(168)	(193)
Loans, net of allowance	49,022	46,589
Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	20,360	18,780
Subscription Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	14,415	13,138
Fund finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	11,060	10,916
Real Money Funds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	8,740	8,300
Business Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,570	1,750
Collateralized loan obligations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	13,046	12,809
Broadly syndicated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10,230	10,300
Middle market
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,810	2,510
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,523	2,851
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,311	2,471
Overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,345	1,962
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,490	2,635
Securities Finance Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,370	2,520
Municipal Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	120	120
Floating Rate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 43,490
Fixed Rate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 2,350