<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.10.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>190</ContextCount>
  <ElementCount>230</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>43</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - CONSOLIDATED STATEMENTS OF INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ConsolidatedStatementsOfIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002000 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002001 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ConsolidatedStatementsOfComprehensiveIncomeLossParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1003501 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/CondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1004000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - BASIS OF PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/BasisOfPresentation</Role>
      <ShortName>BASIS OF PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - REVENUE RECOGNITION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RevenueRecognition</Role>
      <ShortName>REVENUE RECOGNITION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - EARNINGS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/EarningsPerShare</Role>
      <ShortName>EARNINGS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - ACQUISITIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/Acquisitions</Role>
      <ShortName>ACQUISITIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - SEGMENT INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/SegmentInformation</Role>
      <ShortName>SEGMENT INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - RATIONALIZATION AND ASSET IMPAIRMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RationalizationAndAssetImpairments</Role>
      <ShortName>RATIONALIZATION AND ASSET IMPAIRMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/Equity</Role>
      <ShortName>EQUITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - INVENTORY VALUATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/InventoryValuation</Role>
      <ShortName>INVENTORY VALUATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/Contingencies</Role>
      <ShortName>CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - PRODUCT WARRANTY COSTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ProductWarrantyCosts</Role>
      <ShortName>PRODUCT WARRANTY COSTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/Debt</Role>
      <ShortName>DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - RETIREMENT AND POSTRETIREMENT BENEFIT PLANS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RetirementAndPostretirementBenefitPlans</Role>
      <ShortName>RETIREMENT AND POSTRETIREMENT BENEFIT PLANS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2117100 - Disclosure - OTHER INCOME (EXPENSE)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/OtherIncomeExpense</Role>
      <ShortName>OTHER INCOME (EXPENSE)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2118100 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/IncomeTaxes</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2119100 - Disclosure - DERIVATIVES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/Derivatives</Role>
      <ShortName>DERIVATIVES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2120100 - Disclosure - FAIR VALUE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/FairValue</Role>
      <ShortName>FAIR VALUE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - BASIS OF PRESENTATION (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/BasisOfPresentationPolicies</Role>
      <ShortName>BASIS OF PRESENTATION (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2302301 - Disclosure - REVENUE RECOGNITION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RevenueRecognitionTables</Role>
      <ShortName>REVENUE RECOGNITION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RevenueRecognition</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - EARNINGS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/EarningsPerShareTables</Role>
      <ShortName>EARNINGS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/EarningsPerShare</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - ACQUISITIONS Acquisitions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/AcquisitionsAcquisitionsTables</Role>
      <ShortName>ACQUISITIONS Acquisitions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - SEGMENT INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/SegmentInformationTables</Role>
      <ShortName>SEGMENT INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/SegmentInformation</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - RATIONALIZATION AND ASSET IMPAIRMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RationalizationAndAssetImpairmentsTables</Role>
      <ShortName>RATIONALIZATION AND ASSET IMPAIRMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RationalizationAndAssetImpairments</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - EQUITY (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/EquityTables</Role>
      <ShortName>EQUITY (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/Equity</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - INVENTORY VALUATION Schedule of Inventory, Current (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/InventoryValuationScheduleOfInventoryCurrentTables</Role>
      <ShortName>INVENTORY VALUATION Schedule of Inventory, Current (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - PRODUCT WARRANTY COSTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ProductWarrantyCostsTables</Role>
      <ShortName>PRODUCT WARRANTY COSTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/ProductWarrantyCosts</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - RETIREMENT AND POSTRETIREMENT BENEFIT PLANS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RetirementAndPostretirementBenefitPlansTables</Role>
      <ShortName>RETIREMENT AND POSTRETIREMENT BENEFIT PLANS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RetirementAndPostretirementBenefitPlans</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2317301 - Disclosure - OTHER INCOME (EXPENSE) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/OtherIncomeExpenseTables</Role>
      <ShortName>OTHER INCOME (EXPENSE) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/OtherIncomeExpense</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2319301 - Disclosure - DERIVATIVES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DerivativesTables</Role>
      <ShortName>DERIVATIVES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/Derivatives</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2320301 - Disclosure - FAIR VALUE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/FairValueTables</Role>
      <ShortName>FAIR VALUE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/FairValue</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2401402 - Disclosure - BASIS OF PRESENTATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/BasisOfPresentationDetails</Role>
      <ShortName>BASIS OF PRESENTATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/BasisOfPresentationPolicies</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2402402 - Disclosure - REVENUE RECOGNITION (Disaggregation of Revenue) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RevenueRecognitionDisaggregationOfRevenueDetails</Role>
      <ShortName>REVENUE RECOGNITION (Disaggregation of Revenue) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RevenueRecognitionTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2402403 - Disclosure - REVENUE RECOGNITION (Textual) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RevenueRecognitionTextualDetails</Role>
      <ShortName>REVENUE RECOGNITION (Textual) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RevenueRecognitionTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - EARNINGS PER SHARE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/EarningsPerShareDetails</Role>
      <ShortName>EARNINGS PER SHARE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/EarningsPerShareTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - ACQUISITIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/AcquisitionsDetails</Role>
      <ShortName>ACQUISITIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/AcquisitionsAcquisitionsTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - SEGMENT INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/SegmentInformationDetails</Role>
      <ShortName>SEGMENT INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/SegmentInformationTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - RATIONALIZATION AND ASSET IMPAIRMENTS Summary of Activity Related to Rationalization Liabilities by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RationalizationAndAssetImpairmentsSummaryOfActivityRelatedToRationalizationLiabilitiesBySegmentDetails</Role>
      <ShortName>RATIONALIZATION AND ASSET IMPAIRMENTS Summary of Activity Related to Rationalization Liabilities by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - RATIONALIZATION AND ASSET IMPAIRMENTS (Textual) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RationalizationAndAssetImpairmentsTextualDetails</Role>
      <ShortName>RATIONALIZATION AND ASSET IMPAIRMENTS (Textual) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RationalizationAndAssetImpairmentsTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - EQUITY (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/EquityDetails</Role>
      <ShortName>EQUITY (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/EquityTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - INVENTORY VALUATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/InventoryValuationDetails</Role>
      <ShortName>INVENTORY VALUATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/InventoryValuationScheduleOfInventoryCurrentTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - PRODUCT WARRANTY COSTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/ProductWarrantyCostsDetails</Role>
      <ShortName>PRODUCT WARRANTY COSTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/ProductWarrantyCostsTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2415401 - Disclosure - DEBT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DebtDetails</Role>
      <ShortName>DEBT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/Debt</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - RETIREMENT AND POSTRETIREMENT BENEFIT PLANS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/RetirementAndPostretirementBenefitPlansDetails</Role>
      <ShortName>RETIREMENT AND POSTRETIREMENT BENEFIT PLANS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/RetirementAndPostretirementBenefitPlansTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2417402 - Disclosure - OTHER INCOME (EXPENSE) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/OtherIncomeExpenseDetails</Role>
      <ShortName>OTHER INCOME (EXPENSE) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/OtherIncomeExpenseTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2418401 - Disclosure - INCOME TAXES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/IncomeTaxesDetails</Role>
      <ShortName>INCOME TAXES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/IncomeTaxes</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2419402 - Disclosure - DERIVATIVES (Fair Value of Derivative Instruments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DerivativesFairValueOfDerivativeInstrumentsDetails</Role>
      <ShortName>DERIVATIVES (Fair Value of Derivative Instruments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/DerivativesTables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2419403 - Disclosure - DERIVATIVES (Income Statement Impact) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DerivativesIncomeStatementImpactDetails</Role>
      <ShortName>DERIVATIVES (Income Statement Impact) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/DerivativesTables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2419404 - Disclosure - DERIVATIVES (AOCI Impact) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DerivativesAociImpactDetails</Role>
      <ShortName>DERIVATIVES (AOCI Impact) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/DerivativesTables</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2419405 - Disclosure - DERIVATIVES (Textual) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/DerivativesTextualDetails</Role>
      <ShortName>DERIVATIVES (Textual) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/DerivativesTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2420402 - Disclosure - FAIR VALUE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/FairValueDetails</Role>
      <ShortName>FAIR VALUE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/FairValueTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="leco-20180930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2420403 - Disclosure - FAIR VALUE (Textual) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lincolnelectric.com/role/FairValueTextualDetails</Role>
      <ShortName>FAIR VALUE (Textual) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lincolnelectric.com/role/FairValueTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>leco-20180930.xml</File>
    <File>leco-20180930.xsd</File>
    <File>leco-20180930_cal.xml</File>
    <File>leco-20180930_def.xml</File>
    <File>leco-20180930_lab.xml</File>
    <File>leco-20180930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/us-gaap/2017-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2014-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/invest/2013-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
