XML 12 R1.htm IDEA: XBRL DOCUMENT v3.19.2
Document And Entity Information - shares
 9 Months Ended
Jun. 01, 2019
Jun. 19, 2019
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 01, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Registrant Name MSC INDUSTRIAL DIRECT CO INC  
Entity Central Index Key 0001003078  
Current Fiscal Year End Date --08-31  
Entity Filer Category Large Accelerated Filer  
Entity Emerging Growth Company false  
Entity Small Business false  
Entity Shell Company false  
Entity Current Reporting Status Yes  
Class A Common Stock [Member]    
Entity Common Stock, Shares Outstanding   45,008,191
Class B Common Stock [Member]    
Entity Common Stock, Shares Outstanding   10,193,348