v3.22.4
Debt - Senior Secured Credit Facilities (Details) - USD ($)
12 Months Ended
Jan. 10, 2023
Dec. 14, 2022
Feb. 25, 2019
Dec. 31, 2022
Jan. 01, 2022
Jan. 02, 2021
Debt            
Repayments of term loan       $ 122,536,000 $ 329,010,000 $ 674,045,000
Summit Materials, LLC            
Debt            
Repayments of term loan       122,536,000 329,010,000 $ 674,045,000
Summit Materials, LLC | Term Loan, due 2027:            
Debt            
Debt instrument, face amount   $ 509,600,000   $ 509,600,000    
Effective interest rate       7.61%    
Repayments of term loan       $ 95,600,000    
Summit Materials, LLC | Revolving Credit Facility            
Debt            
Maximum borrowing capacity       $ 345,000,000    
Basis spread on variable rate       0.25%    
Amount outstanding       $ 0 $ 0  
Remaining borrowing capacity       325,200,000    
Summit Materials, LLC | Revolving Credit Facility | Subsequent Event            
Debt            
Maximum borrowing capacity $ 395,000,000          
Summit Materials, LLC | Revolving Credit Facility | Base Rate            
Debt            
Basis spread on variable rate   2.00%        
Summit Materials, LLC | Revolving Credit Facility | Base Rate | Minimum            
Debt            
Basis spread on variable rate   1.00%        
Summit Materials, LLC | Revolving Credit Facility | SOFR            
Debt            
Basis spread on variable rate   3.00%        
Summit Materials, LLC | Revolving Credit Facility | SOFR adjustment            
Debt            
Basis spread on variable rate   0.10%        
Summit Materials, LLC | Revolving Credit Facility | SOFR adjustment | Minimum            
Debt            
Basis spread on variable rate   0.00%        
Summit Materials, LLC | Revolving Credit Facility | SOFR adjustment | Subsequent Event            
Debt            
Basis spread on variable rate 0.10%          
Summit Materials, LLC | Revolving Credit Facility | SOFR adjustment | Subsequent Event | Minimum            
Debt            
Basis spread on variable rate 0.00%          
Summit Materials, LLC | Revolving Credit Facility | Federal funds rate            
Debt            
Basis spread on variable rate     0.50%      
Summit Materials, LLC | Revolving Credit Facility | LIBOR Plus 1%            
Debt            
Basis spread on variable rate     2.00%      
Percentage added to base rate     1.00%      
Summit Materials, LLC | Revolving Credit Facility | LIBOR            
Debt            
Basis spread on variable rate     3.00%      
Summit Materials, LLC | Letter of Credit            
Debt            
Amount outstanding       $ 19,800,000    
Summit Materials, LLC | Senior Secured Credit Facilities            
Debt            
First lien leverage ratio       4.75