<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>567</ContextCount>
  <ElementCount>464</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>146</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>1001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1002 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1003 - Statement - Consolidated Statements of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1004 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1005 - Statement - Consolidated Statements of Changes in Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ConsolidatedStatementsOfChangesInEquity</Role>
      <ShortName>Consolidated Statements of Changes in Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure</Role>
      <ShortName>Cybersecurity Risk Management and Strategy Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>999001 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>999002 - Disclosure - Financial Risk Management</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/FinancialRiskManagement</Role>
      <ShortName>Financial Risk Management</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>999003 - Disclosure - Critical Accounting Judgments, Estimates and Assumptions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CriticalAccountingJudgmentsEstimatesAndAssumptions</Role>
      <ShortName>Critical Accounting Judgments, Estimates and Assumptions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>999004 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>999005 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/Revenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>999006 - Disclosure - Expenses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/Expenses</Role>
      <ShortName>Expenses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>999007 - Disclosure - Income Tax Expense</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpense</Role>
      <ShortName>Income Tax Expense</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>999008 - Disclosure - Cash and Cash Equivalents</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CashAndCashEquivalents</Role>
      <ShortName>Cash and Cash Equivalents</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>999009 - Disclosure - Current Receivables</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentReceivables</Role>
      <ShortName>Current Receivables</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>999010 - Disclosure - Short Term Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShortTermInvestments</Role>
      <ShortName>Short Term Investments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>999011 - Disclosure - Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/OtherCurrentAssets</Role>
      <ShortName>Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>999012 - Disclosure - Derivative Financial Asset</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DerivativeFinancialAsset</Role>
      <ShortName>Derivative Financial Asset</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>999013 - Disclosure - Other Non-Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/OtherNonCurrentAssets</Role>
      <ShortName>Other Non-Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>999014 - Disclosure - Non-Current Assets - Plant and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsPlantAndEquipment</Role>
      <ShortName>Non-Current Assets - Plant and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>999015 - Disclosure - Non-Current Assets - Intangibles</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsIntangibles</Role>
      <ShortName>Non-Current Assets - Intangibles</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>999016 - Disclosure - Deferred Tax Balances</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DeferredTaxBalances</Role>
      <ShortName>Deferred Tax Balances</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>999017 - Disclosure - Current Liabilities - Trade and Other Payables</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesTradeAndOtherPayables</Role>
      <ShortName>Current Liabilities - Trade and Other Payables</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>999018 - Disclosure - Non-Current Liabilities - Other</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesOther</Role>
      <ShortName>Non-Current Liabilities - Other</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>999019 - Disclosure - Current Liabilities - Convertible Note</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNote</Role>
      <ShortName>Current Liabilities - Convertible Note</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>999020 - Disclosure - Current Liabilities - Employee Benefits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesEmployeeBenefits</Role>
      <ShortName>Current Liabilities - Employee Benefits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>999021 - Disclosure - Non Current Liabilities - Employee Benefits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesEmployeeBenefits</Role>
      <ShortName>Non Current Liabilities - Employee Benefits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>999022 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>999023 - Disclosure - Contributed Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContributedEquity</Role>
      <ShortName>Contributed Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>999024 - Disclosure - Equity - Reserves and Retained Earnings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EquityReservesAndRetainedEarnings</Role>
      <ShortName>Equity - Reserves and Retained Earnings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>999025 - Disclosure - Equity &amp;#8211; Dividends</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EquityDividends</Role>
      <ShortName>Equity &amp;#8211; Dividends</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>999026 - Disclosure - Key Management Personnel Disclosures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/KeyManagementPersonnelDisclosures</Role>
      <ShortName>Key Management Personnel Disclosures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>999027 - Disclosure - Remuneration of Auditors</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RemunerationOfAuditors</Role>
      <ShortName>Remuneration of Auditors</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>999028 - Disclosure - Contingent Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContingentLiabilities</Role>
      <ShortName>Contingent Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>999029 - Disclosure - Commitments for Expenditure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CommitmentsForExpenditure</Role>
      <ShortName>Commitments for Expenditure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>999030 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>999031 - Disclosure - Subsidiaries</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/Subsidiaries</Role>
      <ShortName>Subsidiaries</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>999032 - Disclosure - Events Occurring After the Reporting Date</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EventsOccurringAfterTheReportingDate</Role>
      <ShortName>Events Occurring After the Reporting Date</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>999033 - Disclosure - Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ReconciliationOfLossAfterIncomeTaxToNetCashUsedInOperatingActivities</Role>
      <ShortName>Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>999034 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>999035 - Disclosure - Share-Based Payments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPayments</Role>
      <ShortName>Share-Based Payments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>999036 - Disclosure - Parent Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ParentEntityInformation</Role>
      <ShortName>Parent Entity Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>999037 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.immutep.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>999038 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>999039 - Disclosure - Financial Risk Management (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/FinancialRiskManagementTables</Role>
      <ShortName>Financial Risk Management (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/FinancialRiskManagement</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>999040 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/SegmentReporting</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>999041 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/Revenue</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>999042 - Disclosure - Expenses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ExpensesTables</Role>
      <ShortName>Expenses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/Expenses</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>999043 - Disclosure - Income Tax Expense (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpenseTables</Role>
      <ShortName>Income Tax Expense (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/IncomeTaxExpense</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>999044 - Disclosure - Cash and Cash Equivalents (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CashAndCashEquivalentsTables</Role>
      <ShortName>Cash and Cash Equivalents (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/CashAndCashEquivalents</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>999045 - Disclosure - Current Receivables (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentReceivablesTables</Role>
      <ShortName>Current Receivables (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/CurrentReceivables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>999046 - Disclosure - Short Term Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShortTermInvestmentsTables</Role>
      <ShortName>Short Term Investments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/ShortTermInvestments</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>999047 - Disclosure - Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/OtherCurrentAssetsTables</Role>
      <ShortName>Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/OtherCurrentAssets</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>999048 - Disclosure - Derivative Financial Asset (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DerivativeFinancialAssetTables</Role>
      <ShortName>Derivative Financial Asset (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/DerivativeFinancialAsset</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>999049 - Disclosure - Other Non-Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/OtherNonCurrentAssetsTables</Role>
      <ShortName>Other Non-Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/OtherNonCurrentAssets</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>999050 - Disclosure - Non-Current Assets - Plant and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsPlantAndEquipmentTables</Role>
      <ShortName>Non-Current Assets - Plant and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/NonCurrentAssetsPlantAndEquipment</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>999051 - Disclosure - Non-Current Assets - Intangibles (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsIntangiblesTables</Role>
      <ShortName>Non-Current Assets - Intangibles (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/NonCurrentAssetsIntangibles</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>999052 - Disclosure - Deferred Tax Balances (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DeferredTaxBalancesTables</Role>
      <ShortName>Deferred Tax Balances (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/DeferredTaxBalances</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>999053 - Disclosure - Current Liabilites - Trade and Other Payables (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitesTradeAndOtherPayablesTables</Role>
      <ShortName>Current Liabilites - Trade and Other Payables (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>999054 - Disclosure - Non-Current Liabilities - Other (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesOtherTables</Role>
      <ShortName>Non-Current Liabilities - Other (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/NonCurrentLiabilitiesOther</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>999055 - Disclosure - Current Liabilities - Convertible Note (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNoteTables</Role>
      <ShortName>Current Liabilities - Convertible Note (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNote</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>999056 - Disclosure - Current Liabilities - Employee Benefits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesEmployeeBenefitsTables</Role>
      <ShortName>Current Liabilities - Employee Benefits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/CurrentLiabilitiesEmployeeBenefits</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>999057 - Disclosure - Non Current Liabilities - Employee Benefits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesEmployeeBenefitsTables</Role>
      <ShortName>Non Current Liabilities - Employee Benefits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/NonCurrentLiabilitiesEmployeeBenefits</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>999058 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/Leases</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>999059 - Disclosure - Contributed Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContributedEquityTables</Role>
      <ShortName>Contributed Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/ContributedEquity</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>999060 - Disclosure - Equity - Reserves and Retained Earnings (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EquityReservesAndRetainedEarningsTables</Role>
      <ShortName>Equity - Reserves and Retained Earnings (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/EquityReservesAndRetainedEarnings</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>999061 - Disclosure - Key Management Personnel Disclosures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/KeyManagementPersonnelDisclosuresTables</Role>
      <ShortName>Key Management Personnel Disclosures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/KeyManagementPersonnelDisclosures</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>999062 - Disclosure - Remuneration of Auditors (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RemunerationOfAuditorsTables</Role>
      <ShortName>Remuneration of Auditors (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/RemunerationOfAuditors</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>999063 - Disclosure - Subsidiaries (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SubsidiariesTables</Role>
      <ShortName>Subsidiaries (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/Subsidiaries</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>999064 - Disclosure - Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ReconciliationOfLossAfterIncomeTaxToNetCashUsedInOperatingActivitiesTables</Role>
      <ShortName>Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/ReconciliationOfLossAfterIncomeTaxToNetCashUsedInOperatingActivities</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>999065 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/EarningsPerShare</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>999066 - Disclosure - Share-Based Payments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsTables</Role>
      <ShortName>Share-Based Payments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/ShareBasedPayments</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>999067 - Disclosure - Parent Entity Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ParentEntityInformationTables</Role>
      <ShortName>Parent Entity Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.immutep.com/role/ParentEntityInformation</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>999068 - Disclosure - Summary of Significant Accounting Policies - Summary of Depreciation on Tangible Assets Estimated Useful Lives (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SummaryOfSignificantAccountingPoliciesSummaryOfDepreciationOnTangibleAssetsEstimatedUsefulLivesDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Depreciation on Tangible Assets Estimated Useful Lives (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>999069 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>999070 - Disclosure - Financial Risk Management - Summary of Exposure to Foreign Currency Risk (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/FinancialRiskManagementSummaryOfExposureToForeignCurrencyRiskDetail</Role>
      <ShortName>Financial Risk Management - Summary of Exposure to Foreign Currency Risk (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>999071 - Disclosure - Financial Risk Management - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/FinancialRiskManagementAdditionalInformationDetail</Role>
      <ShortName>Financial Risk Management - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>999072 - Disclosure - Financial Risk Management - Summary of Contractual Undiscounted Cash Flows (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/FinancialRiskManagementSummaryOfContractualUndiscountedCashFlowsDetail</Role>
      <ShortName>Financial Risk Management - Summary of Contractual Undiscounted Cash Flows (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>999073 - Disclosure - Financial Risk Management - Summary of Financial Assets and Financial Liabilities Measured and Recognized at Fair Value (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/FinancialRiskManagementSummaryOfFinancialAssetsAndFinancialLiabilitiesMeasuredAndRecognizedAtFairValueDetail</Role>
      <ShortName>Financial Risk Management - Summary of Financial Assets and Financial Liabilities Measured and Recognized at Fair Value (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>999074 - Disclosure - Critical Accounting Judgements, Estimates And Assumptions - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CriticalAccountingJudgementsEstimatesAndAssumptionsAdditionalInformationDetail</Role>
      <ShortName>Critical Accounting Judgements, Estimates And Assumptions - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>999075 - Disclosure - Segment Reporting - Disclosure of Operating Segment Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SegmentReportingDisclosureOfOperatingSegmentInformationDetail</Role>
      <ShortName>Segment Reporting - Disclosure of Operating Segment Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>999076 - Disclosure - Revenue - Summary of detailed information about licensing revenue explanatory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RevenueSummaryOfDetailedInformationAboutLicensingRevenueExplanatoryDetails</Role>
      <ShortName>Revenue - Summary of detailed information about licensing revenue explanatory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>999077 - Disclosure - Revenue - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RevenueAdditionalInformationDetail</Role>
      <ShortName>Revenue - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>999078 - Disclosure - Expenses - Disclosure of Expenses (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ExpensesDisclosureOfExpensesDetail</Role>
      <ShortName>Expenses - Disclosure of Expenses (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>999079 - Disclosure - Income Tax Expense - Disclosure of Income Tax Expense Benefit (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpenseDisclosureOfIncomeTaxExpenseBenefitDetail</Role>
      <ShortName>Income Tax Expense - Disclosure of Income Tax Expense Benefit (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>999080 - Disclosure - Income Tax Expense - Disclosure of Reconciliation of Income Tax Expense to Prima Facie Tax Payable (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpenseDisclosureOfReconciliationOfIncomeTaxExpenseToPrimaFacieTaxPayableDetail</Role>
      <ShortName>Income Tax Expense - Disclosure of Reconciliation of Income Tax Expense to Prima Facie Tax Payable (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>999081 - Disclosure - Income Tax Expense - Disclosure of Reconciliation of Income Tax Expense to Prima Facie Tax Payable (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpenseDisclosureOfReconciliationOfIncomeTaxExpenseToPrimaFacieTaxPayableParentheticalDetail</Role>
      <ShortName>Income Tax Expense - Disclosure of Reconciliation of Income Tax Expense to Prima Facie Tax Payable (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>999082 - Disclosure - Income Tax Expense - Disclosure of Deferred Tax Assets Liability Adjustments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpenseDisclosureOfDeferredTaxAssetsLiabilityAdjustmentsDetail</Role>
      <ShortName>Income Tax Expense - Disclosure of Deferred Tax Assets Liability Adjustments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>999083 - Disclosure - Income Tax Expense - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/IncomeTaxExpenseAdditionalInformationDetail</Role>
      <ShortName>Income Tax Expense - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>999084 - Disclosure - Cash and Cash Equivalents - Disclosure of Cash and Cash Equivalents (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CashAndCashEquivalentsDisclosureOfCashAndCashEquivalentsDetail</Role>
      <ShortName>Cash and Cash Equivalents - Disclosure of Cash and Cash Equivalents (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>999085 - Disclosure - Cash and Cash Equivalents - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CashAndCashEquivalentsAdditionalInformationDetail</Role>
      <ShortName>Cash and Cash Equivalents - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>999086 - Disclosure - Current Receivables - Disclosure of Current Receivables (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentReceivablesDisclosureOfCurrentReceivablesDetail</Role>
      <ShortName>Current Receivables - Disclosure of Current Receivables (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>999087 - Disclosure - Short Term Investments - Summary of Short Term Investments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShortTermInvestmentsSummaryOfShortTermInvestmentsDetail</Role>
      <ShortName>Short Term Investments - Summary of Short Term Investments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>999088 - Disclosure - Short Term Investments - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShortTermInvestmentsAdditionalInformationDetail</Role>
      <ShortName>Short Term Investments - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>999089 - Disclosure - Other Current Assets - Disclosure of Other Current Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/OtherCurrentAssetsDisclosureOfOtherCurrentAssetsDetail</Role>
      <ShortName>Other Current Assets - Disclosure of Other Current Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>999090 - Disclosure - Derivative Financial Asset - Summary of Derivative Financial Asset (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DerivativeFinancialAssetSummaryOfDerivativeFinancialAssetDetail</Role>
      <ShortName>Derivative Financial Asset - Summary of Derivative Financial Asset (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>999091 - Disclosure - Derivative Financial Asset - Summary of detailed information about derivative financial asset explanatory (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DerivativeFinancialAssetSummaryOfDetailedInformationAboutDerivativeFinancialAssetExplanatoryDetail</Role>
      <ShortName>Derivative Financial Asset - Summary of detailed information about derivative financial asset explanatory (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>999092 - Disclosure - Derivative Financial Asset - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DerivativeFinancialAssetAdditionalInformationDetail</Role>
      <ShortName>Derivative Financial Asset - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>999093 - Disclosure - Other Non-Current Assets - Disclosure of Other Noncurrent Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/OtherNonCurrentAssetsDisclosureOfOtherNoncurrentAssetsDetail</Role>
      <ShortName>Other Non-Current Assets - Disclosure of Other Noncurrent Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>999094 - Disclosure - Non-Current Assets - Plant and Equipment - Disclosure of Non-Current Assets - Plant and Equipment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsPlantAndEquipmentDisclosureOfNonCurrentAssetsPlantAndEquipmentDetail</Role>
      <ShortName>Non-Current Assets - Plant and Equipment - Disclosure of Non-Current Assets - Plant and Equipment (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>999095 - Disclosure - Non-Current Assets - Intangibles - Disclosure of Non-Current Assets - Intangibles (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsIntangiblesDisclosureOfNonCurrentAssetsIntangiblesDetail</Role>
      <ShortName>Non-Current Assets - Intangibles - Disclosure of Non-Current Assets - Intangibles (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>999096 - Disclosure - Non-Current Assets - Intangibles - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentAssetsIntangiblesAdditionalInformationDetail</Role>
      <ShortName>Non-Current Assets - Intangibles - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>999097 - Disclosure - Deferred Tax Balances - Deferred Tax Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DeferredTaxBalancesDeferredTaxAssetsDetail</Role>
      <ShortName>Deferred Tax Balances - Deferred Tax Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>999098 - Disclosure - Deferred Tax Balances - Deferred Tax Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DeferredTaxBalancesDeferredTaxLiabilitiesDetail</Role>
      <ShortName>Deferred Tax Balances - Deferred Tax Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>999099 - Disclosure - Deferred Tax Balances - Movements in Deferred Tax Balances (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/DeferredTaxBalancesMovementsInDeferredTaxBalancesDetail</Role>
      <ShortName>Deferred Tax Balances - Movements in Deferred Tax Balances (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>999100 - Disclosure - Current Liabilites - Trade and Other Payables - Summary of Current Liabilities Trade and Other Payables (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitesTradeAndOtherPayablesSummaryOfCurrentLiabilitiesTradeAndOtherPayablesDetail</Role>
      <ShortName>Current Liabilites - Trade and Other Payables - Summary of Current Liabilities Trade and Other Payables (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>999101 - Disclosure - Non-Current Liabilities - Other - Summary of Other Non-Current Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesOtherSummaryOfOtherNonCurrentLiabilitiesDetail</Role>
      <ShortName>Non-Current Liabilities - Other - Summary of Other Non-Current Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>999102 - Disclosure - Non-Current Liabilities - Other - Summary of Other Non-Current Liabilities (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesOtherSummaryOfOtherNonCurrentLiabilitiesParentheticalDetail</Role>
      <ShortName>Non-Current Liabilities - Other - Summary of Other Non-Current Liabilities (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>999103 - Disclosure - Current Liabilities - Convertible note - Summary of convertible note explanatory (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNoteSummaryOfConvertibleNoteExplanatoryDetail</Role>
      <ShortName>Current Liabilities - Convertible note - Summary of convertible note explanatory (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>999104 - Disclosure - Current Liabilities - Convertible Note - Summary of convertible note at fair value (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNoteSummaryOfConvertibleNoteAtFairValueDetail</Role>
      <ShortName>Current Liabilities - Convertible Note - Summary of convertible note at fair value (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>999105 - Disclosure - Current Liabilities - Convertible Note - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNoteAdditionalInformationDetail</Role>
      <ShortName>Current Liabilities - Convertible Note - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>999106 - Disclosure - Current Liabilities - Convertible Note - Summary of Assumptions Which were Based on Market Conditions that Existed at Grant Date (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNoteSummaryOfAssumptionsWhichWereBasedOnMarketConditionsThatExistedAtGrantDateDetail</Role>
      <ShortName>Current Liabilities - Convertible Note - Summary of Assumptions Which were Based on Market Conditions that Existed at Grant Date (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>999107 - Disclosure -  Current Liabilities - Convertible Note - Summary of Fair Value of Convertible Notes (Detail)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesConvertibleNoteSummaryOfFairValueOfConvertibleNotesDetail</Role>
      <ShortName> Current Liabilities - Convertible Note - Summary of Fair Value of Convertible Notes (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>999108 - Disclosure - Current Liabilities - Employee Benefits - Summary of Detailed Information of Employee Benefits Current Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CurrentLiabilitiesEmployeeBenefitsSummaryOfDetailedInformationOfEmployeeBenefitsCurrentLiabilitiesDetail</Role>
      <ShortName>Current Liabilities - Employee Benefits - Summary of Detailed Information of Employee Benefits Current Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>999109 - Disclosure - Non Current Liabilities - Employee Benefits - Summary of Detailed Information of Employee Benefits Non Current Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/NonCurrentLiabilitiesEmployeeBenefitsSummaryOfDetailedInformationOfEmployeeBenefitsNonCurrentLiabilitiesDetail</Role>
      <ShortName>Non Current Liabilities - Employee Benefits - Summary of Detailed Information of Employee Benefits Non Current Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>116</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>999110 - Disclosure - Leases - Summary of Lease Asset and Liability (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/LeasesSummaryOfLeaseAssetAndLiabilityDetail</Role>
      <ShortName>Leases - Summary of Lease Asset and Liability (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>999111 - Disclosure - Leases - Summary of Aging of Lease Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/LeasesSummaryOfAgingOfLeaseLiabilitiesDetail</Role>
      <ShortName>Leases - Summary of Aging of Lease Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>118</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>999112 - Disclosure - Leases - Summary of Recognised ROU Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/LeasesSummaryOfRecognisedRouAssetsDetail</Role>
      <ShortName>Leases - Summary of Recognised ROU Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>119</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>999113 - Disclosure - Leases - Summary of Movement of Lease Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/LeasesSummaryOfMovementOfLeaseLiabilitiesDetail</Role>
      <ShortName>Leases - Summary of Movement of Lease Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>120</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>999114 - Disclosure - Leases - Summary of Maturity Analysis of Lease Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/LeasesSummaryOfMaturityAnalysisOfLeaseLiabilitiesDetail</Role>
      <ShortName>Leases - Summary of Maturity Analysis of Lease Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>121</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>999115 - Disclosure - Contributed Equity - Summary of Contributed Equity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContributedEquitySummaryOfContributedEquityDetail</Role>
      <ShortName>Contributed Equity - Summary of Contributed Equity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>122</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>999116 - Disclosure - Contributed Equity - Summary of Ordinary Shares (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContributedEquitySummaryOfOrdinarySharesDetail</Role>
      <ShortName>Contributed Equity - Summary of Ordinary Shares (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>123</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>999117 - Disclosure - Contributed Equity - Summary of Shares Issued (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContributedEquitySummaryOfSharesIssuedDetail</Role>
      <ShortName>Contributed Equity - Summary of Shares Issued (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>124</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>999118 - Disclosure - Contributed Equity - Summary of Unlisted Options (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContributedEquitySummaryOfUnlistedOptionsDetail</Role>
      <ShortName>Contributed Equity - Summary of Unlisted Options (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>125</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>999119 - Disclosure - Equity - Reserves and Retained Earnings - Summary of Equity Reserves and Retained Earnings (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EquityReservesAndRetainedEarningsSummaryOfEquityReservesAndRetainedEarningsDetail</Role>
      <ShortName>Equity - Reserves and Retained Earnings - Summary of Equity Reserves and Retained Earnings (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>126</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R127.htm</HtmlFileName>
      <LongName>999120 - Disclosure - Equity &amp;#8211; Dividends - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EquityDividendsAdditionalInformationDetail</Role>
      <ShortName>Equity &amp;#8211; Dividends - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>127</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R128.htm</HtmlFileName>
      <LongName>999121 - Disclosure - Key Management Personnel Disclosures - Summary of Directors and Key Management Personnel Compensation (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/KeyManagementPersonnelDisclosuresSummaryOfDirectorsAndKeyManagementPersonnelCompensationDetail</Role>
      <ShortName>Key Management Personnel Disclosures - Summary of Directors and Key Management Personnel Compensation (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>128</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R129.htm</HtmlFileName>
      <LongName>999122 - Disclosure - Key Management Personnel Disclosures - Summary of Number of Shares Held in Company (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/KeyManagementPersonnelDisclosuresSummaryOfNumberOfSharesHeldInCompanyDetail</Role>
      <ShortName>Key Management Personnel Disclosures - Summary of Number of Shares Held in Company (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>129</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R130.htm</HtmlFileName>
      <LongName>999123 - Disclosure - Key Management Personnel Disclosures - Summary of Number of Performance Rights Over Ordinary Shares in Parent Entity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/KeyManagementPersonnelDisclosuresSummaryOfNumberOfPerformanceRightsOverOrdinarySharesInParentEntityDetail</Role>
      <ShortName>Key Management Personnel Disclosures - Summary of Number of Performance Rights Over Ordinary Shares in Parent Entity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>130</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R131.htm</HtmlFileName>
      <LongName>999124 - Disclosure - Remuneration of Auditors - Summary of Detailed Information About Auditors Remuneration (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RemunerationOfAuditorsSummaryOfDetailedInformationAboutAuditorsRemunerationDetail</Role>
      <ShortName>Remuneration of Auditors - Summary of Detailed Information About Auditors Remuneration (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>131</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R132.htm</HtmlFileName>
      <LongName>999125 - Disclosure - Contingent Liabilities - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ContingentLiabilitiesAdditionalInformationDetail</Role>
      <ShortName>Contingent Liabilities - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>132</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R133.htm</HtmlFileName>
      <LongName>999126 - Disclosure - Commitments for Expenditure - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/CommitmentsForExpenditureAdditionalInformationDetail</Role>
      <ShortName>Commitments for Expenditure - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>133</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R134.htm</HtmlFileName>
      <LongName>999127 - Disclosure - Related Party Transactions - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/RelatedPartyTransactionsAdditionalInformationDetail</Role>
      <ShortName>Related Party Transactions - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>134</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R135.htm</HtmlFileName>
      <LongName>999128 - Disclosure - Subsidiaries - Summary of Subsidiaries (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/SubsidiariesSummaryOfSubsidiariesDetail</Role>
      <ShortName>Subsidiaries - Summary of Subsidiaries (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>135</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R136.htm</HtmlFileName>
      <LongName>999129 - Disclosure - Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities - Summary of Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ReconciliationOfLossAfterIncomeTaxToNetCashUsedInOperatingActivitiesSummaryOfReconciliationOfLossAfterIncomeTaxToNetCashUsedInOperatingActivitiesDetail</Role>
      <ShortName>Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities - Summary of Reconciliation of Loss After Income Tax to Net Cash Used in Operating Activities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>136</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R137.htm</HtmlFileName>
      <LongName>999130 - Disclosure - Earnings Per Share - Summary of Earnings Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EarningsPerShareSummaryOfEarningsPerShareDetail</Role>
      <ShortName>Earnings Per Share - Summary of Earnings Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>137</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R138.htm</HtmlFileName>
      <LongName>999131 - Disclosure - Earnings Per Share - Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/EarningsPerShareSummaryOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetail</Role>
      <ShortName>Earnings Per Share - Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>138</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R139.htm</HtmlFileName>
      <LongName>999132 - Disclosure - Share-Based Payments - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsAdditionalInformationDetail</Role>
      <ShortName>Share-Based Payments - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>139</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R140.htm</HtmlFileName>
      <LongName>999133 - Disclosure - Share-Based Payments - Summaries of All STI and LTI Performance Rights Granted (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsSummariesOfAllStiAndLtiPerformanceRightsGrantedDetail</Role>
      <ShortName>Share-Based Payments - Summaries of All STI and LTI Performance Rights Granted (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>140</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R141.htm</HtmlFileName>
      <LongName>999134 - Disclosure - Share-Based Payments - Model Inputs for STI Performance Rights Granted (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsModelInputsForStiPerformanceRightsGrantedDetail</Role>
      <ShortName>Share-Based Payments - Model Inputs for STI Performance Rights Granted (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>141</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R142.htm</HtmlFileName>
      <LongName>999135 - Disclosure - Share-Based Payments - Model Inputs for STI Performance Rights Granted (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsModelInputsForStiPerformanceRightsGrantedParentheticalDetail</Role>
      <ShortName>Share-Based Payments - Model Inputs for STI Performance Rights Granted (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>142</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R143.htm</HtmlFileName>
      <LongName>999136 - Disclosure - Share-Based Payments - Summary of Performance Rights Granted (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsSummaryOfPerformanceRightsGrantedDetail</Role>
      <ShortName>Share-Based Payments - Summary of Performance Rights Granted (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>143</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R144.htm</HtmlFileName>
      <LongName>999137 - Disclosure - Share-Based Payments - Summary of Options Granted (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsSummaryOfOptionsGrantedDetail</Role>
      <ShortName>Share-Based Payments - Summary of Options Granted (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>144</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R145.htm</HtmlFileName>
      <LongName>999138 - Disclosure - Share-Based Payments - Total Expenses Arising from Share-Based Payment Transactions (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ShareBasedPaymentsTotalExpensesArisingFromShareBasedPaymentTransactionsDetail</Role>
      <ShortName>Share-Based Payments - Total Expenses Arising from Share-Based Payment Transactions (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>145</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R146.htm</HtmlFileName>
      <LongName>999139 - Disclosure - Parent Entity Information - Statement of Comprehensive Income (Loss) of Parent Entity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ParentEntityInformationStatementOfComprehensiveIncomeLossOfParentEntityDetail</Role>
      <ShortName>Parent Entity Information - Statement of Comprehensive Income (Loss) of Parent Entity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>146</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R147.htm</HtmlFileName>
      <LongName>999140 - Disclosure - Parent Entity Information - Statement of Financial Position of Parent Entity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ParentEntityInformationStatementOfFinancialPositionOfParentEntityDetail</Role>
      <ShortName>Parent Entity Information - Statement of Financial Position of Parent Entity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>147</Position>
    </Report>
    <Report instance="d109552d20f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R148.htm</HtmlFileName>
      <LongName>999141 - Disclosure - Parent Entity Information - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.immutep.com/role/ParentEntityInformationAdditionalInformationDetail</Role>
      <ShortName>Parent Entity Information - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>148</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="20-F" isDefinitelyFs="true" isIfrs="true" isUsgaap="true" original="d109552d20f.htm">d109552d20f.htm</File>
    <File>immp-20260630.xsd</File>
  </InputFiles>
  <SupplementalFiles>
    <File>g109552g1013033749974.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="11">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="46">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="1">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
    <BaseTaxonomy items="1436">https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
