<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>212</ContextCount>
  <ElementCount>275</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>66</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>9</UnitCount>
  <MyReports>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>9952151 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952152 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952153 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952154 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONSParenthetical</Role>
      <ShortName>UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952155 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME</Role>
      <ShortName>UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952156 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952157 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY</Role>
      <ShortName>UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952158 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical</Role>
      <ShortName>UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - BASIS OF PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/BASISOFPRESENTATION</Role>
      <ShortName>BASIS OF PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SIGNIFICANTACCOUNTINGPOLICIES</Role>
      <ShortName>SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - REVENUES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REVENUES</Role>
      <ShortName>REVENUES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - BUSINESS COMBINATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/BUSINESSCOMBINATIONS</Role>
      <ShortName>BUSINESS COMBINATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - INVENTORIES AND SUPPLIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIES</Role>
      <ShortName>INVENTORIES AND SUPPLIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - PROPERTY, PLANT AND EQUIPMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENT</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETS</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIES</Role>
      <ShortName>ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - CLOSURE AND POST-CLOSURE LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIES</Role>
      <ShortName>CLOSURE AND POST-CLOSURE LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - REMEDIAL LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REMEDIALLIABILITIES</Role>
      <ShortName>REMEDIAL LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - FINANCING ARRANGEMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/FINANCINGARRANGEMENTS</Role>
      <ShortName>FINANCING ARRANGEMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9952170 - Disclosure - EARNINGS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/EARNINGSPERSHARE</Role>
      <ShortName>EARNINGS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9952171 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSS</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE LOSS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9952172 - Disclosure - STOCK-BASED COMPENSATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATION</Role>
      <ShortName>STOCK-BASED COMPENSATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9952173 - Disclosure - COMMITMENTS AND CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/COMMITMENTSANDCONTINGENCIES</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9952174 - Disclosure - SEGMENT REPORTING</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SEGMENTREPORTING</Role>
      <ShortName>SEGMENT REPORTING</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.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>26</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SIGNIFICANTACCOUNTINGPOLICIESPolicies</Role>
      <ShortName>SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - REVENUES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REVENUESTables</Role>
      <ShortName>REVENUES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/REVENUES</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - BUSINESS COMBINATIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/BUSINESSCOMBINATIONSTables</Role>
      <ShortName>BUSINESS COMBINATIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/BUSINESSCOMBINATIONS</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - INVENTORIES AND SUPPLIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIESTables</Role>
      <ShortName>INVENTORIES AND SUPPLIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIES</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENTTables</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENT</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSTables</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETS</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESTables</Role>
      <ShortName>ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIES</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - CLOSURE AND POST-CLOSURE LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIESTables</Role>
      <ShortName>CLOSURE AND POST-CLOSURE LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIES</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - REMEDIAL LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REMEDIALLIABILITIESTables</Role>
      <ShortName>REMEDIAL LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/REMEDIALLIABILITIES</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - FINANCING ARRANGEMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/FINANCINGARRANGEMENTSTables</Role>
      <ShortName>FINANCING ARRANGEMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/FINANCINGARRANGEMENTS</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - EARNINGS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/EARNINGSPERSHARETables</Role>
      <ShortName>EARNINGS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/EARNINGSPERSHARE</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSTables</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSS</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - STOCK-BASED COMPENSATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONTables</Role>
      <ShortName>STOCK-BASED COMPENSATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATION</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - SEGMENT REPORTING (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SEGMENTREPORTINGTables</Role>
      <ShortName>SEGMENT REPORTING (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/SEGMENTREPORTING</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - REVENUES - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REVENUESAdditionalInformationDetails</Role>
      <ShortName>REVENUES - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - REVENUES - Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REVENUESDisaggregationofRevenueDetails</Role>
      <ShortName>REVENUES - Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - REVENUES - Contract Balances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REVENUESContractBalancesDetails</Role>
      <ShortName>REVENUES - Contract Balances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - BUSINESS COMBINATIONS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/BUSINESSCOMBINATIONSAdditionalInformationDetails</Role>
      <ShortName>BUSINESS COMBINATIONS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - BUSINESS COMBINATIONS - Assets Acquired and Liabilities Assumed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/BUSINESSCOMBINATIONSAssetsAcquiredandLiabilitiesAssumedDetails</Role>
      <ShortName>BUSINESS COMBINATIONS - Assets Acquired and Liabilities Assumed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - INVENTORIES AND SUPPLIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIESDetails</Role>
      <ShortName>INVENTORIES AND SUPPLIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIESTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENTScheduleofPropertyPlantandEquipmentDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENTAdditionalInformationDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSChangestoGoodwillDetails</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Finite-lived and Indefinite Lived Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSFinitelivedandIndefiniteLivedIntangibleAssetsDetails</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS - Finite-lived and Indefinite Lived Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSAdditionalInformationDetails</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Expected Future Amortization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSExpectedFutureAmortizationDetails</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS - Expected Future Amortization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESDetails</Role>
      <ShortName>ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESTables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - CLOSURE AND POST-CLOSURE LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIESDetails</Role>
      <ShortName>CLOSURE AND POST-CLOSURE LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIESTables</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - REMEDIAL LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/REMEDIALLIABILITIESDetails</Role>
      <ShortName>REMEDIAL LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/REMEDIALLIABILITIESTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - FINANCING ARRANGEMENTS - Schedule of Financing Arrangements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/FINANCINGARRANGEMENTSScheduleofFinancingArrangementsDetails</Role>
      <ShortName>FINANCING ARRANGEMENTS - Schedule of Financing Arrangements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - FINANCING ARRANGEMENTS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/FINANCINGARRANGEMENTSAdditionalInformationDetails</Role>
      <ShortName>FINANCING ARRANGEMENTS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - EARNINGS PER SHARE - Reconciliation of Basic and Diluted Earnings Per Share Computations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/EARNINGSPERSHAREReconciliationofBasicandDilutedEarningsPerShareComputationsDetails</Role>
      <ShortName>EARNINGS PER SHARE - Reconciliation of Basic and Diluted Earnings Per Share Computations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - EARNINGS PER SHARE - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/EARNINGSPERSHAREAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails</Role>
      <ShortName>EARNINGS PER SHARE - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS - Changes in Accumulated Other Comprehensive Loss by Component (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE LOSS - Changes in Accumulated Other Comprehensive Loss by Component (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassified Out of Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSReclassifiedOutofAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassified Out of Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - STOCK-BASED COMPENSATION - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONAdditionalInformationDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONRestrictedStockAwardsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - STOCK-BASED COMPENSATION - Performance Stock Awards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONPerformanceStockAwardsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Performance Stock Awards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/COMMITMENTSANDCONTINGENCIESDetails</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cleanharbors.com/role/COMMITMENTSANDCONTINGENCIES</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - SEGMENT REPORTING - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SEGMENTREPORTINGAdditionalInformationDetails</Role>
      <ShortName>SEGMENT REPORTING - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SEGMENTREPORTINGReconciliationofThirdPartyRevenuestoDirectRevenuesDetails</Role>
      <ShortName>SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - SEGMENT REPORTING - Adjusted EBITDA and Significant Segment Expense Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SEGMENTREPORTINGAdjustedEBITDAandSignificantSegmentExpenseInformationDetails</Role>
      <ShortName>SEGMENT REPORTING - Adjusted EBITDA and Significant Segment Expense Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="clh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - SEGMENT REPORTING - Reconciliation to Consolidated Statements of Income to Adjusted EBITDA (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cleanharbors.com/role/SEGMENTREPORTINGReconciliationtoConsolidatedStatementsofIncometoAdjustedEBITDADetails</Role>
      <ShortName>SEGMENT REPORTING - Reconciliation to Consolidated Statements of Income to Adjusted EBITDA (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</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-Q" isDefinitelyFs="true" isUsgaap="true" original="clh-20260331.htm">clh-20260331.htm</File>
    <File>clh-20260331.xsd</File>
    <File>clh-20260331_cal.xml</File>
    <File>clh-20260331_def.xml</File>
    <File>clh-20260331_lab.xml</File>
    <File>clh-20260331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>clh-20260331_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="700">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
