Annual report pursuant to Section 13 and 15(d)

Business Acquisitions - Additional Information (Details)

v3.21.2
Business Acquisitions - Additional Information (Details)
$ in Thousands
 12 Months Ended
Sep. 30, 2021
USD ($)
acquisition
plant
Sep. 30, 2020
USD ($)
acquisition
Sep. 30, 2019
USD ($)
acquisition
Jul. 30, 2021
plant
Jul. 30, 2021
facility
Business Acquisition [Line Items]          
Number of manufacturing plants | plant 2        
Goodwill $ 85,422 $ 46,348 $ 38,546    
Purchase price allocation, maximum valuation period 1 year        
Interest expense $ 1,300        
North Carolina Acquisitions - Final          
Business Acquisition [Line Items]          
Number of production and paving companies acquired | acquisition 5        
Number of plants added | plant 14        
Number of businesses acquired | acquisition 6        
Total consideration transferred $ 97,885        
Goodwill 33,320        
General and administrative expenses 600        
North Carolina Acquisitions Provisional          
Business Acquisition [Line Items]          
Total consideration transferred 31,200        
Goodwill 2,600        
General and administrative expenses 300        
Alabama Acquisition - Provisional          
Business Acquisition [Line Items]          
Total consideration transferred 81,682        
Goodwill 3,157        
General and administrative expenses 400        
Number of aggregate facilities       4 4
All Acquisitions for Fiscal Year          
Business Acquisition [Line Items]          
Number of businesses acquired | acquisition   2 2    
Total consideration transferred 210,734 $ 27,500 $ 13,900    
Goodwill 39,074 $ 7,800 $ 5,600    
Revenues since acquisition date 79,300        
Net loss $ (4,900)