Document And Entity Information - shares
 9 Months Ended
May 30, 2020
Jun. 15, 2020
Class of Stock [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date May 30, 2020  
Document Transition Report false  
Entity File Number 1-14130  
Entity Registrant Name MSC INDUSTRIAL DIRECT CO., INC.  
Entity Incorporation, State or Country Code NY  
Entity Tax Identification Number 11-3289165  
Entity Address, Address Line One 75 Maxess Road  
Entity Address, City or Town Melville  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 11747  
City Area Code 516  
Local Phone Number 812-2000  
Title of 12(b) Security Class A Common Stock, par value $.001  
Trading Symbol MSM  
Security Exchange Name NYSE  
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 Central Index Key 0001003078  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q3  
Current Fiscal Year End Date --08-29  
Amendment Flag false  
Class A Common Stock [Member]    
Class of Stock [Line Items]    
Entity Common Stock, Shares Outstanding   45,525,464
Class B Common Stock [Member]    
Class of Stock [Line Items]    
Entity Common Stock, Shares Outstanding   10,054,856