v3.25.4
Property, Plant and Equipment - Property,Plant and Equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross $ 1,770,158 $ 1,650,680
Accumulated depreciation, depletion, and amortization (560,898) (526,370)
Construction in progress 43,775 28,760
Total property, plant and equipment, net 1,253,035 1,153,070
Construction equipment    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 824,974 766,914
Plants    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 450,997 413,983
Land and improvements    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 213,639 202,120
Mineral reserves    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 201,440 201,440
Buildings    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 68,525 54,583
Furniture and fixtures    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 9,152 10,209
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross $ 1,431 $ 1,431