v3.26.1
Intangible Assets, Goodwill, Acquisitions and Divestitures - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
Sep. 30, 2025
Sep. 30, 2024
Finite Lived Intangible Assets [Line Items]            
Amortization of intangible assets $ 5.3 $ 7.1 $ 11.5 $ 15.2    
Intangible assets acquired 0.0 $ 0.0 0.0 $ 0.0    
Goodwill 2,015.7   2,015.7   $ 2,015.7 $ 2,015.7
Maintenance Services segment            
Finite Lived Intangible Assets [Line Items]            
Goodwill 1,797.7   1,797.7   1,797.7 1,797.7
Development Services segment.            
Finite Lived Intangible Assets [Line Items]            
Goodwill $ 218.0   $ 218.0   $ 218.0 $ 218.0