XML 113 R92.htm IDEA: XBRL DOCUMENT v3.25.3
Revenue from Contracts with Clients - Schedule of Income and Expense (Details) - Equity Positions - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disaggregation of Revenue [Line Items]      
Dividend (loss)/income net of dividend expense reported within Principal Gains, net $ (0.1) $ 1.1 $ (1.3)
Long      
Disaggregation of Revenue [Line Items]      
Dividend (loss)/income net of dividend expense reported within Principal Gains, net 142.3 192.3 32.0
Short      
Disaggregation of Revenue [Line Items]      
Dividend (loss)/income net of dividend expense reported within Principal Gains, net $ (142.4) $ (191.2) $ (33.3)