v3.22.4
Cover - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2022
Feb. 13, 2023
Jul. 02, 2022
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2022    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-36873    
Entity Registrant Name SUMMIT MATERIALS, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 47-1984212    
Entity Address, Address Line One 1801 California Street    
Entity Address, Address Line Two Suite 3500    
Entity Address, City or Town Denver    
Entity Address, State or Province CO    
Entity Address, Postal Zip Code 80202    
City Area Code 303    
Local Phone Number 893-0012    
Title of 12(b) Security Class A Common Stock (par value $.01 per share)    
Trading Symbol SUM    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 2.7
Documents Incorporated by Reference Certain information required by Items 10, 11, 12, 13 and 14 of Part III incorporate information by reference from Summit Materials, Inc.’s definitive proxy statement relating to its 2023 annual meeting of stockholders to be filed with the Securities and Exchange Commission within 120 days after the close of Summit Materials, Inc.’s most recent fiscal year.    
Entity Central Index Key 0001621563    
Amendment Flag false    
Document Fiscal Year Focus 2022    
Document Fiscal Period Focus FY    
Common Class A      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   118,427,867  
Common Class B      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   99  
Summit Materials, LLC      
Document Information [Line Items]      
Entity File Number 333-187556    
Entity Registrant Name SUMMIT MATERIALS, LLC    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 26-4138486    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Central Index Key 0001571371    
Amendment Flag false    
Document Fiscal Year Focus 2022    
Document Fiscal Period Focus FY