<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>291</ContextCount>
  <ElementCount>519</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>83</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952151 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952152 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952153 - Statement - CONSOLIDATED STATEMENTS OF INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDSTATEMENTSOFINCOME</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952154 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952155 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952156 - Statement - CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952157 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952158 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - REVENUE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/REVENUE</Role>
      <ShortName>REVENUE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - FAIR VALUE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/FAIRVALUE</Role>
      <ShortName>FAIR VALUE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - NET INCOME PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/NETINCOMEPERSHARE</Role>
      <ShortName>NET INCOME PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - ACCOUNTS RECEIVABLE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCOUNTSRECEIVABLE</Role>
      <ShortName>ACCOUNTS RECEIVABLE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - ACQUISITIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACQUISITIONS</Role>
      <ShortName>ACQUISITIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - PROPERTY, PLANT AND EQUIPMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/PROPERTYPLANTANDEQUIPMENT</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - ASSET IMPAIRMENTS AND RELATED CHARGES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSETIMPAIRMENTSANDRELATEDCHARGES</Role>
      <ShortName>ASSET IMPAIRMENTS AND RELATED CHARGES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXES</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIES</Role>
      <ShortName>ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/DEBT</Role>
      <ShortName>DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/LEASES</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9952170 - Disclosure - SHAREHOLDERS’ EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SHAREHOLDERSEQUITY</Role>
      <ShortName>SHAREHOLDERS’ EQUITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9952171 - Disclosure - ASSOCIATE BENEFIT PLANS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSOCIATEBENEFITPLANS</Role>
      <ShortName>ASSOCIATE BENEFIT PLANS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9952172 - Disclosure - RESTRUCTURING AND OTHER COSTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/RESTRUCTURINGANDOTHERCOSTS</Role>
      <ShortName>RESTRUCTURING AND OTHER COSTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9952173 - Disclosure - COMMITMENTS AND CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/COMMITMENTSANDCONTINGENCIES</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9952174 - Disclosure - SEGMENT REPORTING</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SEGMENTREPORTING</Role>
      <ShortName>SEGMENT REPORTING</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9952175 - Disclosure - SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTS</Role>
      <ShortName>SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure</Role>
      <ShortName>Cybersecurity Risk Management and Strategy Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policy)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicy</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policy)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - REVENUE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/REVENUETables</Role>
      <ShortName>REVENUE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/REVENUE</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - NET INCOME PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/NETINCOMEPERSHARETables</Role>
      <ShortName>NET INCOME PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/NETINCOMEPERSHARE</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - ACCOUNTS RECEIVABLE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCOUNTSRECEIVABLETables</Role>
      <ShortName>ACCOUNTS RECEIVABLE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/ACCOUNTSRECEIVABLE</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/PROPERTYPLANTANDEQUIPMENTTables</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/PROPERTYPLANTANDEQUIPMENT</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - INCOME TAXES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESTables</Role>
      <ShortName>INCOME TAXES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/INCOMETAXES</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESTables</Role>
      <ShortName>ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIES</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/DEBTTables</Role>
      <ShortName>DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/DEBT</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/LEASESTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/LEASES</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - ASSOCIATE BENEFIT PLANS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSOCIATEBENEFITPLANSTables</Role>
      <ShortName>ASSOCIATE BENEFIT PLANS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/ASSOCIATEBENEFITPLANS</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - RESTRUCTURING AND OTHER COSTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/RESTRUCTURINGANDOTHERCOSTSTables</Role>
      <ShortName>RESTRUCTURING AND OTHER COSTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/RESTRUCTURINGANDOTHERCOSTS</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - SEGMENT REPORTING (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SEGMENTREPORTINGTables</Role>
      <ShortName>SEGMENT REPORTING (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/SEGMENTREPORTING</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Change in the Carrying Amount of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofChangeintheCarryingAmountofGoodwillDetails</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Change in the Carrying Amount of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Components of Other Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofComponentsofOtherIntangibleAssetsDetails</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Components of Other Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Estimated Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/BUSINESSANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofEstimatedAmortizationExpenseDetails</Role>
      <ShortName>BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Estimated Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - REVENUE - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/REVENUENarrativeDetails</Role>
      <ShortName>REVENUE - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - REVENUE - Schedule of Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/REVENUEScheduleofDisaggregationofRevenueDetails</Role>
      <ShortName>REVENUE - Schedule of Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - FAIR VALUE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/FAIRVALUEDetails</Role>
      <ShortName>FAIR VALUE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/FAIRVALUE</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - NET INCOME PER SHARE - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/NETINCOMEPERSHARENarrativeDetails</Role>
      <ShortName>NET INCOME PER SHARE - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - NET INCOME PER SHARE - Schedule of Computation Of Basic And Diluted Net Income Per Common Share Under Treasury Stock Method (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/NETINCOMEPERSHAREScheduleofComputationOfBasicAndDilutedNetIncomePerCommonShareUnderTreasuryStockMethodDetails</Role>
      <ShortName>NET INCOME PER SHARE - Schedule of Computation Of Basic And Diluted Net Income Per Common Share Under Treasury Stock Method (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - ACCOUNTS RECEIVABLE - Schedule of Accounts Receivables (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCOUNTSRECEIVABLEScheduleofAccountsReceivablesDetails</Role>
      <ShortName>ACCOUNTS RECEIVABLE - Schedule of Accounts Receivables (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - ACCOUNTS RECEIVABLE - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCOUNTSRECEIVABLENarrativeDetails</Role>
      <ShortName>ACCOUNTS RECEIVABLE - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - ACCOUNTS RECEIVABLE - Schedule of Activity and Amounts Outstanding Under the RPA (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCOUNTSRECEIVABLEScheduleofActivityandAmountsOutstandingUndertheRPADetails</Role>
      <ShortName>ACCOUNTS RECEIVABLE - Schedule of Activity and Amounts Outstanding Under the RPA (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - ACQUISITIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACQUISITIONSDetails</Role>
      <ShortName>ACQUISITIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/ACQUISITIONS</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/PROPERTYPLANTANDEQUIPMENTScheduleofPropertyPlantandEquipmentDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/PROPERTYPLANTANDEQUIPMENTNarrativeDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - ASSET IMPAIRMENTS AND RELATED CHARGES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSETIMPAIRMENTSANDRELATEDCHARGESDetails</Role>
      <ShortName>ASSET IMPAIRMENTS AND RELATED CHARGES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/ASSETIMPAIRMENTSANDRELATEDCHARGES</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - INCOME TAXES - Schedule of Components of Income Before Provision for Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofComponentsofIncomeBeforeProvisionforIncomeTaxesDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Components of Income Before Provision for Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - INCOME TAXES - Schedule of Provision For Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofProvisionForIncomeTaxesDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Provision For Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - INCOME TAXES - Schedule of Income Taxes Paid, Net of Refunds Received (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofIncomeTaxesPaidNetofRefundsReceivedDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Income Taxes Paid, Net of Refunds Received (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - INCOME TAXES - Schedule of Components of Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofComponentsofDeferredTaxAssetsandLiabilitiesDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Components of Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - INCOME TAXES - Schedule of Valuation Allowance Changed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofValuationAllowanceChangedDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Valuation Allowance Changed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - INCOME TAXES - Schedule of Reconciliation of Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofReconciliationofIncomeTaxExpenseDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Reconciliation of Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - INCOME TAXES - Schedule of Changes In Gross Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESScheduleofChangesInGrossUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>INCOME TAXES - Schedule of Changes In Gross Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - INCOME TAXES - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/INCOMETAXESNarrativeDetails</Role>
      <ShortName>INCOME TAXES - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESDetails</Role>
      <ShortName>ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESTables</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - DEBT - Schedule of Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/DEBTScheduleofDebtDetails</Role>
      <ShortName>DEBT - Schedule of Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - DEBT - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/DEBTNarrativeDetails</Role>
      <ShortName>DEBT - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - DEBT - Schedule Of Maturities of Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/DEBTScheduleOfMaturitiesofDebtDetails</Role>
      <ShortName>DEBT - Schedule Of Maturities of Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - LEASES - Schedule of Components of lease cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/LEASESScheduleofComponentsofleasecostDetails</Role>
      <ShortName>LEASES - Schedule of Components of lease cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - LEASES - Schedule of Supplemental Balance Sheet Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/LEASESScheduleofSupplementalBalanceSheetInformationDetails</Role>
      <ShortName>LEASES - Schedule of Supplemental Balance Sheet Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>9955554 - Disclosure - LEASES - Schedule of Supplemental Cash Flow Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/LEASESScheduleofSupplementalCashFlowInformationDetails</Role>
      <ShortName>LEASES - Schedule of Supplemental Cash Flow Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>9955555 - Disclosure - LEASES - Schedule of Future Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/LEASESScheduleofFutureLeasePaymentsDetails</Role>
      <ShortName>LEASES - Schedule of Future Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>9955556 - Disclosure - SHAREHOLDERS’ EQUITY (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SHAREHOLDERSEQUITYDetails</Role>
      <ShortName>SHAREHOLDERS’ EQUITY (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/SHAREHOLDERSEQUITY</ParentRole>
      <Position>76</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>9955557 - Disclosure - ASSOCIATE BENEFIT PLANS - Schedule of Stock-Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSOCIATEBENEFITPLANSScheduleofStockBasedCompensationExpenseDetails</Role>
      <ShortName>ASSOCIATE BENEFIT PLANS - Schedule of Stock-Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>9955558 - Disclosure - ASSOCIATE BENEFIT PLANS - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSOCIATEBENEFITPLANSNarrativeDetails</Role>
      <ShortName>ASSOCIATE BENEFIT PLANS - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>9955559 - Disclosure - ASSOCIATE BENEFIT PLANS - Schedule of Restricted Stock Units and Performance Stock Units (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/ASSOCIATEBENEFITPLANSScheduleofRestrictedStockUnitsandPerformanceStockUnitsDetails</Role>
      <ShortName>ASSOCIATE BENEFIT PLANS - Schedule of Restricted Stock Units and Performance Stock Units (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>9955560 - Disclosure - RESTRUCTURING AND OTHER COSTS - Schedule of Restructuring Charges (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/RESTRUCTURINGANDOTHERCOSTSScheduleofRestructuringChargesDetails</Role>
      <ShortName>RESTRUCTURING AND OTHER COSTS - Schedule of Restructuring Charges (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>9955561 - Disclosure - RESTRUCTURING AND OTHER COSTS - Schedule of Restructuring Related Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/RESTRUCTURINGANDOTHERCOSTSScheduleofRestructuringRelatedLiabilitiesDetails</Role>
      <ShortName>RESTRUCTURING AND OTHER COSTS - Schedule of Restructuring Related Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>9955562 - Disclosure - SEGMENT REPORTING (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SEGMENTREPORTINGDetails</Role>
      <ShortName>SEGMENT REPORTING (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/SEGMENTREPORTINGTables</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="msm-20260829.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>9955563 - Disclosure - SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www1.mscdirect.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails</Role>
      <ShortName>SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www1.mscdirect.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTS</ParentRole>
      <Position>83</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-K" isDefinitelyFs="true" isUsgaap="true" original="msm-20260829.htm">msm-20260829.htm</File>
    <File>msm-20260829.xsd</File>
    <File>msm-20260829_cal.xml</File>
    <File>msm-20260829_def.xml</File>
    <File>msm-20260829_lab.xml</File>
    <File>msm-20260829_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>msm-20260829_g1.jpg</File>
    <File>msm-20260829_g2.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="3">http://fasb.org/srt/2026</BaseTaxonomy>
    <BaseTaxonomy items="1222">http://fasb.org/us-gaap/2026</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/cyd/2026</BaseTaxonomy>
    <BaseTaxonomy items="38">http://xbrl.sec.gov/dei/2026</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2026</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
