<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.8.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>1265</ContextCount>
  <ElementCount>661</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>347</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>17</UnitCount>
  <MyReports>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0006000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Consolidated Statement of Financial Position</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ConsolidatedStatementOfFinancialPosition</Role>
      <ShortName>Consolidated Statement of Financial Position</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002000 - Statement - Consolidated Income Statement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ConsolidatedIncomeStatement</Role>
      <ShortName>Consolidated Income Statement</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003000 - Statement - Consolidated Statement of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ConsolidatedStatementOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statement of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004000 - Statement - Consolidated Statement of Changes in Equity Statement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ConsolidatedStatementOfChangesInEquityStatement</Role>
      <ShortName>Consolidated Statement of Changes in Equity Statement</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005000 - Statement - Consolidated Statement of Cash Flows Statement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ConsolidatedStatementOfCashFlowsStatement</Role>
      <ShortName>Consolidated Statement of Cash Flows Statement</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/NatureOfOperationsAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - CHANGES IN ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ChangesInAccountingPolicies</Role>
      <ShortName>CHANGES IN ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - BUSINESS COMBINATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/BusinessCombinations</Role>
      <ShortName>BUSINESS COMBINATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - ACCOUNTS RECEIVABLE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccountsReceivable</Role>
      <ShortName>ACCOUNTS RECEIVABLE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - INVENTORIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/Inventories</Role>
      <ShortName>INVENTORIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - PROPERTY, PLANT AND EQUIPMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/PropertyPlantAndEquipment</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2119100 - Disclosure - INTANGIBLE ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IntangibleAssets</Role>
      <ShortName>INTANGIBLE ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2122100 - Disclosure - OTHER ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherAssets</Role>
      <ShortName>OTHER ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2125100 - Disclosure - ACCOUNTS PAYABLE AND ACCRUED LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccountsPayableAndAccruedLiabilities</Role>
      <ShortName>ACCOUNTS PAYABLE AND ACCRUED LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2128100 - Disclosure - CONTRACTS IN PROGRESS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ContractsInProgress</Role>
      <ShortName>CONTRACTS IN PROGRESS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2131100 - Disclosure - PROVISIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/Provisions</Role>
      <ShortName>PROVISIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2134100 - Disclosure - DEBT FACILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilities</Role>
      <ShortName>DEBT FACILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2137100 - Disclosure - GOVERNMENT PARTICIPATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/GovernmentParticipation</Role>
      <ShortName>GOVERNMENT PARTICIPATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2140100 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligations</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2143100 - Disclosure - DEFERRED GAINS AND OTHER NON-CURRENT LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DeferredGainsAndOtherNonCurrentLiabilities</Role>
      <ShortName>DEFERRED GAINS AND OTHER NON-CURRENT LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2146100 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxes</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2149100 - Disclosure - SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareCapitalEarningsPerShareAndDividends</Role>
      <ShortName>SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2152100 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccumulatedOtherComprehensiveIncome</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2155100 - Disclosure - EMPLOYEE COMPENSATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeCompensation</Role>
      <ShortName>EMPLOYEE COMPENSATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2158100 - Disclosure - IMPAIRMENT OF NONFINANCIAL ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ImpairmentOfNonfinancialAssets</Role>
      <ShortName>IMPAIRMENT OF NONFINANCIAL ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2161100 - Disclosure - OTHER GAINS - NET</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherGainsNet</Role>
      <ShortName>OTHER GAINS - NET</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2164100 - Disclosure - FINANCE EXPENSE - NET</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinanceExpenseNet</Role>
      <ShortName>FINANCE EXPENSE - NET</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2167100 - Disclosure - SHARE-BASED PAYMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPayments</Role>
      <ShortName>SHARE-BASED PAYMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2170100 - Disclosure - SUPPLEMENTARY CASH FLOWS INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/SupplementaryCashFlowsInformation</Role>
      <ShortName>SUPPLEMENTARY CASH FLOWS INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2173100 - Disclosure - CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/Contingencies</Role>
      <ShortName>CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2176100 - Disclosure - COMMITMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/Commitments</Role>
      <ShortName>COMMITMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2179100 - Disclosure - CAPITAL RISK MANAGEMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/CapitalRiskManagement</Role>
      <ShortName>CAPITAL RISK MANAGEMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2182100 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FairValueOfFinancialInstruments</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2185100 - Disclosure - FINANCIAL RISK MANAGEMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagement</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2188100 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformation</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2191100 - Disclosure - RELATED PARTY RELATIONSHIPS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyRelationships</Role>
      <ShortName>RELATED PARTY RELATIONSHIPS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2194100 - Disclosure - RELATED PARTY TRANSACTIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyTransactions</Role>
      <ShortName>RELATED PARTY TRANSACTIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/NatureOfOperationsAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2301302 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/NatureOfOperationsAndSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/NatureOfOperationsAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - CHANGES IN ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ChangesInAccountingPoliciesTables</Role>
      <ShortName>CHANGES IN ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/ChangesInAccountingPolicies</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - BUSINESS COMBINATIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/BusinessCombinationsTables</Role>
      <ShortName>BUSINESS COMBINATIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/BusinessCombinations</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - ACCOUNTS RECEIVABLE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccountsReceivableTables</Role>
      <ShortName>ACCOUNTS RECEIVABLE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/AccountsReceivable</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - INVENTORIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/InventoriesTables</Role>
      <ShortName>INVENTORIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/Inventories</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/PropertyPlantAndEquipmentTables</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/PropertyPlantAndEquipment</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2319301 - Disclosure - INTANGIBLE ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IntangibleAssetsTables</Role>
      <ShortName>INTANGIBLE ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/IntangibleAssets</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2322301 - Disclosure - OTHER ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherAssetsTables</Role>
      <ShortName>OTHER ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/OtherAssets</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2325301 - Disclosure - ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccountsPayableAndAccruedLiabilitiesTables</Role>
      <ShortName>ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/AccountsPayableAndAccruedLiabilities</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2328301 - Disclosure - CONTRACTS IN PROGRESS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ContractsInProgressTables</Role>
      <ShortName>CONTRACTS IN PROGRESS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/ContractsInProgress</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2331301 - Disclosure - PROVISIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ProvisionsTables</Role>
      <ShortName>PROVISIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/Provisions</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2334301 - Disclosure - DEBT FACILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesTables</Role>
      <ShortName>DEBT FACILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/DebtFacilities</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2337301 - Disclosure - GOVERNMENT PARTICIPATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/GovernmentParticipationTables</Role>
      <ShortName>GOVERNMENT PARTICIPATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/GovernmentParticipation</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2340301 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsTables</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/EmployeeBenefitsObligations</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2343301 - Disclosure - DEFERRED GAINS AND OTHER NON-CURRENT LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DeferredGainsAndOtherNonCurrentLiabilitiesTables</Role>
      <ShortName>DEFERRED GAINS AND OTHER NON-CURRENT LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/DeferredGainsAndOtherNonCurrentLiabilities</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2346301 - Disclosure - INCOME TAXES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxesTables</Role>
      <ShortName>INCOME TAXES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/IncomeTaxes</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2349301 - Disclosure - SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareCapitalEarningsPerShareAndDividendsTables</Role>
      <ShortName>SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/ShareCapitalEarningsPerShareAndDividends</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2352301 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccumulatedOtherComprehensiveIncomeTables</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/AccumulatedOtherComprehensiveIncome</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2355301 - Disclosure - EMPLOYEE COMPENSATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeCompensationTables</Role>
      <ShortName>EMPLOYEE COMPENSATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/EmployeeCompensation</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2358301 - Disclosure - IMPAIRMENT OF NONFINANCIAL ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ImpairmentOfNonfinancialAssetsTables</Role>
      <ShortName>IMPAIRMENT OF NONFINANCIAL ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/ImpairmentOfNonfinancialAssets</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2361301 - Disclosure - OTHER GAINS - NET (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherGainsNetTables</Role>
      <ShortName>OTHER GAINS - NET (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/OtherGainsNet</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2364301 - Disclosure - FINANCE EXPENSE - NET (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinanceExpenseNetTables</Role>
      <ShortName>FINANCE EXPENSE - NET (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/FinanceExpenseNet</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2367301 - Disclosure - SHARE-BASED PAYMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsTables</Role>
      <ShortName>SHARE-BASED PAYMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/ShareBasedPayments</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2370301 - Disclosure - SUPPLEMENTARY CASH FLOWS INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/SupplementaryCashFlowsInformationTables</Role>
      <ShortName>SUPPLEMENTARY CASH FLOWS INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/SupplementaryCashFlowsInformation</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2376301 - Disclosure - COMMITMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/CommitmentsTables</Role>
      <ShortName>COMMITMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/Commitments</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2379301 - Disclosure - CAPITAL RISK MANAGEMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/CapitalRiskManagementTables</Role>
      <ShortName>CAPITAL RISK MANAGEMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/CapitalRiskManagement</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2382301 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FairValueOfFinancialInstrumentsTables</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/FairValueOfFinancialInstruments</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2385301 - Disclosure - FINANCIAL RISK MANAGEMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagementTables</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/FinancialRiskManagement</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2388301 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationTables</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/OperatingSegmentsAndGeographicInformation</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2391301 - Disclosure - RELATED PARTY RELATIONSHIPS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyRelationshipsTables</Role>
      <ShortName>RELATED PARTY RELATIONSHIPS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/RelatedPartyRelationships</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2394301 - Disclosure - RELATED PARTY TRANSACTIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyTransactionsTables</Role>
      <ShortName>RELATED PARTY TRANSACTIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cae.com/role/RelatedPartyTransactions</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2401403 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/NatureOfOperationsAndSummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/NatureOfOperationsAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - CHANGES IN ACCOUNTING POLICIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ChangesInAccountingPoliciesDetails</Role>
      <ShortName>CHANGES IN ACCOUNTING POLICIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/ChangesInAccountingPoliciesTables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - BUSINESS COMBINATIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/BusinessCombinationsDetails</Role>
      <ShortName>BUSINESS COMBINATIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/BusinessCombinationsTables</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - BUSINESS COMBINATIONS - Net Assets and Liabilities from Acquisition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/BusinessCombinationsNetAssetsAndLiabilitiesFromAcquisitionDetails</Role>
      <ShortName>BUSINESS COMBINATIONS - Net Assets and Liabilities from Acquisition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - ACCOUNTS RECEIVABLE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccountsReceivableDetails</Role>
      <ShortName>ACCOUNTS RECEIVABLE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/AccountsReceivableTables</ParentRole>
      <Position>75</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - INVENTORIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/InventoriesDetails</Role>
      <ShortName>INVENTORIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/InventoriesTables</ParentRole>
      <Position>76</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>2413403 - Disclosure - INVENTORIES - Cost of Sales (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/InventoriesCostOfSalesDetails</Role>
      <ShortName>INVENTORIES - Cost of Sales (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/PropertyPlantAndEquipmentDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/PropertyPlantAndEquipmentTables</ParentRole>
      <Position>78</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>2419402 - Disclosure - INTANGIBLE ASSETS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IntangibleAssetsDetails</Role>
      <ShortName>INTANGIBLE ASSETS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/IntangibleAssetsTables</ParentRole>
      <Position>79</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>2422402 - Disclosure - OTHER ASSETS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherAssetsDetails</Role>
      <ShortName>OTHER ASSETS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/OtherAssetsTables</ParentRole>
      <Position>80</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>2422403 - Disclosure - OTHER ASSETS -  Payment Receivables (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherAssetsPaymentReceivablesDetails</Role>
      <ShortName>OTHER ASSETS -  Payment Receivables (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>2422404 - Disclosure - OTHER ASSETS - Investments In Finance Lease Contracts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherAssetsInvestmentsInFinanceLeaseContractsDetails</Role>
      <ShortName>OTHER ASSETS - Investments In Finance Lease Contracts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>2425402 - Disclosure - ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccountsPayableAndAccruedLiabilitiesDetails</Role>
      <ShortName>ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/AccountsPayableAndAccruedLiabilitiesTables</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>2428402 - Disclosure - CONTRACTS IN PROGRESS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ContractsInProgressDetails</Role>
      <ShortName>CONTRACTS IN PROGRESS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/ContractsInProgressTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>2431402 - Disclosure - PROVISIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ProvisionsDetails</Role>
      <ShortName>PROVISIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/ProvisionsTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>2434402 - Disclosure - DEBT FACILITIES - Long-term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesLongTermDebtDetails</Role>
      <ShortName>DEBT FACILITIES - Long-term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>2434403 - Disclosure - DEBT FACILITIES - Recourse Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesRecourseDebtDetails</Role>
      <ShortName>DEBT FACILITIES - Recourse Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>2434404 - Disclosure - DEBT FACILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesDetails</Role>
      <ShortName>DEBT FACILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/DebtFacilitiesTables</ParentRole>
      <Position>88</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>2434405 - Disclosure - DEBT FACILITIES - Non-recourse Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesNonRecourseDebtDetails</Role>
      <ShortName>DEBT FACILITIES - Non-recourse Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>2434406 - Disclosure - DEBT FACILITIES - Retirement Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesRetirementPaymentsDetails</Role>
      <ShortName>DEBT FACILITIES - Retirement Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>2434407 - Disclosure - DEBT FACILITIES - Financing Activities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesFinancingActivitiesDetails</Role>
      <ShortName>DEBT FACILITIES - Financing Activities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>2434408 - Disclosure - DEBT FACILITIES - Future Minimum Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DebtFacilitiesFutureMinimumLeasePaymentsDetails</Role>
      <ShortName>DEBT FACILITIES - Future Minimum Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>2437402 - Disclosure - GOVERNMENT PARTICIPATION - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/GovernmentParticipationNarrativeDetails</Role>
      <ShortName>GOVERNMENT PARTICIPATION - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>2437403 - Disclosure - GOVERNMENT PARTICIPATION - Net Contributions Recognized and Amounts Not Yet Received (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/GovernmentParticipationNetContributionsRecognizedAndAmountsNotYetReceivedDetails</Role>
      <ShortName>GOVERNMENT PARTICIPATION - Net Contributions Recognized and Amounts Not Yet Received (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>2437404 - Disclosure - GOVERNMENT PARTICIPATION - Aggregate Contributions Recognized (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/GovernmentParticipationAggregateContributionsRecognizedDetails</Role>
      <ShortName>GOVERNMENT PARTICIPATION - Aggregate Contributions Recognized (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>2440402 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/EmployeeBenefitsObligationsTables</ParentRole>
      <Position>96</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>2440403 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Employee Benefit Obligation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsEmployeeBenefitObligationDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Employee Benefit Obligation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>2440404 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Movement In Defined Benefit Pension Obligation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsMovementInDefinedBenefitPensionObligationDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Movement In Defined Benefit Pension Obligation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>2440405 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Net Periodic Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsNetPeriodicCostsDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Net Periodic Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>2440406 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Plan Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsPlanAssetsDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Plan Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>2440407 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Significant Assumptions Weighted (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsSignificantAssumptionsWeightedDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Significant Assumptions Weighted (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>2440408 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Future Mortality Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsFutureMortalityRateDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Future Mortality Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>2440409 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS - Significant Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsSignificantAssumptionsDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS - Significant Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>2440410 - Disclosure - EMPLOYEE BENEFITS OBLIGATIONS -  Expected Employer Contributions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeBenefitsObligationsExpectedEmployerContributionsDetails</Role>
      <ShortName>EMPLOYEE BENEFITS OBLIGATIONS -  Expected Employer Contributions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>2443402 - Disclosure - DEFERRED GAINS AND OTHER NON-CURRENT LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/DeferredGainsAndOtherNonCurrentLiabilitiesDetails</Role>
      <ShortName>DEFERRED GAINS AND OTHER NON-CURRENT LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/DeferredGainsAndOtherNonCurrentLiabilitiesTables</ParentRole>
      <Position>105</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>2446402 - Disclosure - INCOME TAXES - Reconciliation of Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxesReconciliationOfIncomeTaxesDetails</Role>
      <ShortName>INCOME TAXES - Reconciliation of Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>2446403 - Disclosure - INCOME TAXES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxesDetails</Role>
      <ShortName>INCOME TAXES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/IncomeTaxesTables</ParentRole>
      <Position>107</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>2446404 - Disclosure - INCOME TAXES - Components of the Provision for the Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxesComponentsOfProvisionForIncomeTaxExpenseDetails</Role>
      <ShortName>INCOME TAXES - Components of the Provision for the Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>2446405 - Disclosure - INCOME TAXES - Movements In Temporary Differences (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxesMovementsInTemporaryDifferencesDetails</Role>
      <ShortName>INCOME TAXES - Movements In Temporary Differences (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>2446406 - Disclosure - INCOME TAXES - Non-capital Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/IncomeTaxesNonCapitalLossesDetails</Role>
      <ShortName>INCOME TAXES - Non-capital Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>2449402 - Disclosure - SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareCapitalEarningsPerShareAndDividendsDetails</Role>
      <ShortName>SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/ShareCapitalEarningsPerShareAndDividendsTables</ParentRole>
      <Position>111</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>2449403 - Disclosure - SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS - Earnings per share computation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareCapitalEarningsPerShareAndDividendsEarningsPerShareComputationDetails</Role>
      <ShortName>SHARE CAPITAL, EARNINGS PER SHARE AND DIVIDENDS - Earnings per share computation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>2452402 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/AccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/AccumulatedOtherComprehensiveIncomeTables</ParentRole>
      <Position>113</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>2455402 - Disclosure - EMPLOYEE COMPENSATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/EmployeeCompensationDetails</Role>
      <ShortName>EMPLOYEE COMPENSATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/EmployeeCompensationTables</ParentRole>
      <Position>114</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>2458402 - Disclosure - IMPAIRMENT OF NONFINANCIAL ASSETS - Changes In Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ImpairmentOfNonfinancialAssetsChangesInGoodwillDetails</Role>
      <ShortName>IMPAIRMENT OF NONFINANCIAL ASSETS - Changes In Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>2458403 - Disclosure - IMPAIRMENT OF NONFINANCIAL ASSETS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ImpairmentOfNonfinancialAssetsDetails</Role>
      <ShortName>IMPAIRMENT OF NONFINANCIAL ASSETS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/ImpairmentOfNonfinancialAssetsTables</ParentRole>
      <Position>116</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>2461402 - Disclosure - OTHER GAINS - NET - Gains (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherGainsNetGainsDetails</Role>
      <ShortName>OTHER GAINS - NET - Gains (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>2461403 - Disclosure - OTHER GAINS - NET (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OtherGainsNetDetails</Role>
      <ShortName>OTHER GAINS - NET (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/OtherGainsNetTables</ParentRole>
      <Position>118</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>2464402 - Disclosure - FINANCE EXPENSE - NET (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinanceExpenseNetDetails</Role>
      <ShortName>FINANCE EXPENSE - NET (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/FinanceExpenseNetTables</ParentRole>
      <Position>119</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>2467402 - Disclosure - SHARE-BASED PAYMENTS - Share-based Compensation Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsShareBasedCompensationCostDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - Share-based Compensation Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>120</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>2467403 - Disclosure - SHARE-BASED PAYMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/ShareBasedPaymentsTables</ParentRole>
      <Position>121</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>2467404 - Disclosure - SHARE-BASED PAYMENTS - ESOP Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsEsopActivityDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - ESOP Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>122</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>2467405 - Disclosure - SHARE-BASED PAYMENTS - ESOP Summarized (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsEsopSummarizedDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - ESOP Summarized (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>123</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>2467406 - Disclosure - SHARE-BASED PAYMENTS - Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsAssumptionsDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>124</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>2467407 - Disclosure - SHARE-BASED PAYMENTS - DSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsDsuActivityDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - DSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>125</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>2467408 - Disclosure - SHARE-BASED PAYMENTS - LTI Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsLtiActivityDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - LTI Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>126</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R127.htm</HtmlFileName>
      <LongName>2467409 - Disclosure - SHARE-BASED PAYMENTS - TSR Relative Performance Index (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsTsrRelativePerformanceIndexDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - TSR Relative Performance Index (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>127</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R128.htm</HtmlFileName>
      <LongName>2467410 - Disclosure - SHARE-BASED PAYMENTS - LTI-PSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/ShareBasedPaymentsLtiPsuActivityDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS - LTI-PSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>128</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R129.htm</HtmlFileName>
      <LongName>2470402 - Disclosure - SUPPLEMENTARY CASH FLOWS INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/SupplementaryCashFlowsInformationDetails</Role>
      <ShortName>SUPPLEMENTARY CASH FLOWS INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/SupplementaryCashFlowsInformationTables</ParentRole>
      <Position>129</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R130.htm</HtmlFileName>
      <LongName>2476402 - Disclosure - COMMITMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/CommitmentsDetails</Role>
      <ShortName>COMMITMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/CommitmentsTables</ParentRole>
      <Position>130</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R131.htm</HtmlFileName>
      <LongName>2479402 - Disclosure - CAPITAL RISK MANAGEMENT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/CapitalRiskManagementDetails</Role>
      <ShortName>CAPITAL RISK MANAGEMENT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/CapitalRiskManagementTables</ParentRole>
      <Position>131</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R132.htm</HtmlFileName>
      <LongName>2482402 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FairValueOfFinancialInstrumentsDetails</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/FairValueOfFinancialInstrumentsTables</ParentRole>
      <Position>132</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R133.htm</HtmlFileName>
      <LongName>2485402 - Disclosure - FINANCIAL RISK MANAGEMENT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagementDetails</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/FinancialRiskManagementTables</ParentRole>
      <Position>133</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R134.htm</HtmlFileName>
      <LongName>2485403 - Disclosure - FINANCIAL RISK MANAGEMENT - Maturity Analysis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagementMaturityAnalysisDetails</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT - Maturity Analysis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>134</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R135.htm</HtmlFileName>
      <LongName>2485404 - Disclosure - FINANCIAL RISK MANAGEMENT - Forward Foreign Currency Contracts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagementForwardForeignCurrencyContractsDetails</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT - Forward Foreign Currency Contracts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>135</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R136.htm</HtmlFileName>
      <LongName>2485405 - Disclosure - FINANCIAL RISK MANAGEMENT - Net Income and Other Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagementNetIncomeAndOtherComprehensiveIncomeDetails</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT - Net Income and Other Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>136</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R137.htm</HtmlFileName>
      <LongName>2485406 - Disclosure - FINANCIAL RISK MANAGEMENT - Letters Of Credit And Guarantees (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/FinancialRiskManagementLettersOfCreditAndGuaranteesDetails</Role>
      <ShortName>FINANCIAL RISK MANAGEMENT - Letters Of Credit And Guarantees (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>137</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R138.htm</HtmlFileName>
      <LongName>2488402 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationTables</ParentRole>
      <Position>138</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R139.htm</HtmlFileName>
      <LongName>2488403 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Results by segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationResultsBySegmentDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Results by segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>139</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R140.htm</HtmlFileName>
      <LongName>2488404 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Capital Expenditures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationCapitalExpendituresDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Capital Expenditures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>140</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R141.htm</HtmlFileName>
      <LongName>2488405 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Operating Profit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationOperatingProfitDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Operating Profit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>141</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R142.htm</HtmlFileName>
      <LongName>2488406 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Assets And Liabilities Employed By Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationAssetsAndLiabilitiesEmployedBySegmentDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Assets And Liabilities Employed By Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>142</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R143.htm</HtmlFileName>
      <LongName>2488407 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Products and Services Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationProductsAndServicesInformationDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Products and Services Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>143</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R144.htm</HtmlFileName>
      <LongName>2488408 - Disclosure - OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Geographic information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/OperatingSegmentsAndGeographicInformationGeographicInformationDetails</Role>
      <ShortName>OPERATING SEGMENTS AND GEOGRAPHIC INFORMATION - Geographic information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>144</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R145.htm</HtmlFileName>
      <LongName>2491402 - Disclosure - RELATED PARTY RELATIONSHIPS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyRelationshipsDetails</Role>
      <ShortName>RELATED PARTY RELATIONSHIPS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/RelatedPartyRelationshipsTables</ParentRole>
      <Position>145</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R146.htm</HtmlFileName>
      <LongName>2494402 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyTransactionsDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cae.com/role/RelatedPartyTransactionsTables</ParentRole>
      <Position>146</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R147.htm</HtmlFileName>
      <LongName>2494403 - Disclosure - RELATED PARTY TRANSACTIONS - Outstanding Balances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyTransactionsOutstandingBalancesDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS - Outstanding Balances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>147</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R148.htm</HtmlFileName>
      <LongName>2494404 - Disclosure - RELATED PARTY TRANSACTIONS - Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyTransactionsTransactionsDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS - Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>148</Position>
    </Report>
    <Report instance="cae-20180331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R149.htm</HtmlFileName>
      <LongName>2494405 - Disclosure - RELATED PARTY TRANSACTIONS - Compensation Of Key Management Personnel (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cae.com/role/RelatedPartyTransactionsCompensationOfKeyManagementPersonnelDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS - Compensation Of Key Management Personnel (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>149</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>cae-20180331.xml</File>
    <File>cae-20180331.xsd</File>
    <File>cae-20180331_cal.xml</File>
    <File>cae-20180331_def.xml</File>
    <File>cae-20180331_lab.xml</File>
    <File>cae-20180331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.ifrs.org/taxonomy/2017-03-09/ifrs-full</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2014-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/invest/2013-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2017-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
