v3.25.1
Physical Commodities Inventory (Details) - USD ($)
$ in Millions
Mar. 31, 2025
Sep. 30, 2024
Inventory [Line Items]    
Physical agriculture and energy $ 255.1 $ 169.0
Precious metals - held by broker-dealer subsidiary 503.1 376.6
Physical commodities inventory, net 796.2 681.1
Physical Commodities Inventory - Precious Metals    
Inventory [Line Items]    
Precious metals - held by broker-dealer subsidiary 248.0 207.6
Precious metals - held by non-broker-dealer subsidiaries 293.1 $ 304.5
Raw materials 7.5  
Work in process $ 26.1