v3.26.1
Financial Instruments and Fair Value Measurements - Cash and Cash Equivalents and Restricted Cash (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Sep. 30, 2025
Mar. 31, 2025
Sep. 30, 2024
Fair Value Disclosures [Abstract]        
Cash and equivalents $ 184.9 $ 225.5    
Restricted cash 8.5 3.1    
Cash and equivalents and restricted cash $ 193.4 $ 228.6 $ 212.3 $ 274.2