v3.24.3
Cover - shares
 9 Months Ended
Sep. 30, 2024
Oct. 24, 2024
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2024  
Document Transition Report false  
Entity File Number 000-50924  
Entity Registrant Name BEACON ROOFING SUPPLY, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 36-4173371  
Entity Address, Address Line One 505 Huntmar Park Drive  
Entity Address, Address Line Two Suite 300  
Entity Address, City or Town Herndon  
Entity Address, State or Province VA  
Entity Address, Postal Zip Code 20170  
City Area Code 571  
Local Phone Number 323-3939  
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol BECN  
Security Exchange Name NASDAQ  
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  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   61,887,984
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2024  
Entity Central Index Key 0001124941