| Document And Entity Information | Sep. 10, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Sep. 10, 2020 |
| Entity Registrant Name | MSC Industrial Direct Co., Inc. |
| Entity Incorporation, State or Country Code | NY |
| Entity File Number | 1-14130 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Common Stock, par value $.001 |
| Trading Symbol | MSM |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001003078 |
