XML 19 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document and Entity Information - USD ($)
 12 Months Ended
Aug. 31, 2018
Oct. 17, 2018
Feb. 28, 2018
Document Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Aug. 31, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Trading Symbol wdfc    
Entity Registrant Name WD 40 CO    
Entity Central Index Key 0000105132    
Current Fiscal Year End Date --08-31    
Entity Current Reporting Status Yes    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 1,695,560,161
Entity Common Stock, Shares Outstanding   13,836,690  
Entity Emerging Growth Company false    
Entity Small Business false    
Entity Shell Company false