v3.26.1
Intangible Assets, Goodwill, Acquisitions and Divestitures - Schedule of Intangible Assets (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Sep. 30, 2025
Finite Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 689.3 $ 715.9
Accumulated Amortization (634.3) (649.4)
Customer Relationships    
Finite Lived Intangible Assets [Line Items]    
Gross Carrying Amount 689.3 715.9
Accumulated Amortization $ (634.3) $ (649.4)
Customer Relationships | Minimum    
Finite Lived Intangible Assets [Line Items]    
Estimated Useful Life 6 years  
Customer Relationships | Maximum    
Finite Lived Intangible Assets [Line Items]    
Estimated Useful Life 21 years