Annual report pursuant to Section 13 and 15(d)

Property, Plant and Equipment - Additional Information (Details)

v3.24.3
Property, Plant and Equipment - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2022
Property, Plant and Equipment [Abstract]      
Depreciation, depletion and amortization expense $ 92.6 $ 80.0 $ 68.9
Mineral reserves, net, accumulated depreciation 62.1 63.6  
Asset retirement obligation, depreciation 1.4 1.5  
Capitalized costs, pre-production stripping costs $ 1.7 $ 0.8