XML 54 R1.htm IDEA: XBRL DOCUMENT v3.19.3
Cover Page - USD ($)
$ in Millions
 12 Months Ended
Aug. 31, 2019
Oct. 23, 2019
Feb. 28, 2019
Cover page.      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Aug. 31, 2019    
Document Transition Report false    
Entity Registrant Name ACUITY BRANDS, INC    
Entity Incorporation, State or Country Code DE    
Entity Public Float     $ 4,550
Entity File Number 001-16583    
Entity Tax Identification Number 58-2632672    
Entity Address, Address Line One 1170 Peachtree Street, N.E.    
Entity Address, Address Line Two Suite 2300    
Entity Address, City or Town Atlanta    
Entity Address, State or Province GA    
Entity Address, Postal Zip Code 30309    
City Area Code 404    
Local Phone Number 853-1400    
Title of 12(b) Security Common stock, $0.01 par value per share    
Trading Symbol AYI    
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    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   39,643,111  
Entity Central Index Key 0001144215    
Amendment Flag false    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --08-31