Restricted Cash and Other Restricted Assets (Details) - USD ($) $ in Billions	Sep. 30, 2025	Dec. 31, 2024
Restricted Cash and Cash Equivalent Item [Line Items]
Total restricted cash	$ 28.8	$ 27.5
Cash and securities pledged with clearing organizations for the benefit of customers	42.3	40.7
Fair value of securities restricted in relation to customer activity	17.7	26.8
Deposits with banks
Restricted Cash and Cash Equivalent Item [Line Items]
Total restricted cash	27.5	26.1
Cash and due from banks
Restricted Cash and Cash Equivalent Item [Line Items]
Total restricted cash	1.3	1.4
Segregated for the benefit of securities and cleared derivative customers
Restricted Cash and Cash Equivalent Item [Line Items]
Total restricted cash	19.3	18.7
Cash reserves at non-U.S. central banks and held for other general purposes
Restricted Cash and Cash Equivalent Item [Line Items]
Total restricted cash	$ 9.5	$ 8.8