Annual report pursuant to Section 13 and 15(d)

Property, Plant and Equipment (Detail)

v3.20.2
Property, Plant and Equipment (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross $ 441,491 $ 383,279
Accumulated depreciation, depletion and amortization (209,532) (177,927)
Construction in progress 5,271 518
Total property, plant and equipment, net 237,230 205,870
Depreciation, depletion and amortization expense 39,100 30,100
Construction equipment    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 253,157 214,500
Plants    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 102,392 92,279
Land and improvements    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 40,614 34,365
Quarry reserves    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 20,238 20,678
Buildings    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 18,307 15,458
Furniture and fixtures    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross 5,648 4,864
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, gross $ 1,135 $ 1,135