<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>255</ContextCount>
  <ElementCount>368</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>74</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>9</UnitCount>
  <MyReports>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00090 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00105 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00200 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/StatementConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00300 - Statement - Consolidated Statements of Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/StatementConsolidatedStatementsOfShareholdersEquity</Role>
      <ShortName>Consolidated Statements of Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00400 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>10101 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>10201 - Disclosure - LIQUIDITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLiquidity</Role>
      <ShortName>LIQUIDITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>10301 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeases</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10401 - Disclosure - LICENSE AGREEMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLicenseAgreements</Role>
      <ShortName>LICENSE AGREEMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10501 - Disclosure - LOAN AND SECURITY AGREEMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLoanAndSecurityAgreement</Role>
      <ShortName>LOAN AND SECURITY AGREEMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10601 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficiencies</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10701 - Disclosure - SHAREHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquity</Role>
      <ShortName>SHAREHOLDERS' EQUITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10801 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrants</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10901 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>11001 - Disclosure - COMMITMENTS AND CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>11101 - Disclosure - RELATED PARTY TRANSACTIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>RELATED PARTY TRANSACTIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>11201 - Disclosure - SUPPLEMENTAL FINANCIAL INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureSupplementalFinancialInformation</Role>
      <ShortName>SUPPLEMENTAL FINANCIAL INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11301 - Disclosure - NET LOSS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNetLossPerShare</Role>
      <ShortName>NET LOSS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11401 - Disclosure - FINANCIAL INSTRUMENTS AND SIGNIFICANT CONCENTRATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureFinancialInstrumentsAndSignificantConcentrations</Role>
      <ShortName>FINANCIAL INSTRUMENTS AND SIGNIFICANT CONCENTRATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11501 - Disclosure - SUBSEQUENT EVENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>SUBSEQUENT EVENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>20102 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>30303 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureLeases</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>30603 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficienciesTables</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficiencies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>30803 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsTables</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrants</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>30903 - Disclosure - INCOME TAXES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>INCOME TAXES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureIncomeTaxes</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>31203 - Disclosure - SUPPLEMENTAL FINANCIAL INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureSupplementalFinancialInformationTables</Role>
      <ShortName>SUPPLEMENTAL FINANCIAL INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureSupplementalFinancialInformation</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>31303 - Disclosure - NET LOSS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNetLossPerShareTables</Role>
      <ShortName>NET LOSS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureNetLossPerShare</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>31403 - Disclosure - FINANCIAL INSTRUMENTS AND SIGNIFICANT CONCENTRATIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureFinancialInstrumentsAndSignificantConcentrationsTables</Role>
      <ShortName>FINANCIAL INSTRUMENTS AND SIGNIFICANT CONCENTRATIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureFinancialInstrumentsAndSignificantConcentrations</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>40101 - Disclosure - NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureNatureOfOperationsAndSummaryOfSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>40201 - Disclosure - LIQUIDITY (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLiquidityDetails</Role>
      <ShortName>LIQUIDITY (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureLiquidity</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>40301 - Disclosure - LEASES - Office Space (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesOfficeSpaceDetails</Role>
      <ShortName>LEASES - Office Space (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>40302 - Disclosure - LEASES - Assets and operating lease liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesAssetsAndOperatingLeaseLiabilitiesDetails</Role>
      <ShortName>LEASES - Assets and operating lease liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>40303 - Disclosure - LEASES - Operating lease expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesOperatingLeaseExpenseDetails</Role>
      <ShortName>LEASES - Operating lease expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>40304 - Disclosure - LEASES - Future Operating Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesFutureOperatingLeasePaymentsDetails</Role>
      <ShortName>LEASES - Future Operating Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>40305 - Disclosure - LEASES - Headquarters Lease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesHeadquartersLeaseDetails</Role>
      <ShortName>LEASES - Headquarters Lease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>40306 - Disclosure - LEASES - Future Payments of Lease Yet to Commence (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLeasesFuturePaymentsOfLeaseYetToCommenceDetails</Role>
      <ShortName>LEASES - Future Payments of Lease Yet to Commence (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>40401 - Disclosure - LICENSE AGREEMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLicenseAgreementsDetails</Role>
      <ShortName>LICENSE AGREEMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureLicenseAgreements</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>40501 - Disclosure - LOAN AND SECURITY AGREEMENT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureLoanAndSecurityAgreementDetails</Role>
      <ShortName>LOAN AND SECURITY AGREEMENT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureLoanAndSecurityAgreement</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>40601 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Deficiency Triggered by Issuance of Class B Pre-Funded Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficienciesDeficiencyTriggeredByIssuanceOfClassBPreFundedWarrantsDetails</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Deficiency Triggered by Issuance of Class B Pre-Funded Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>40602 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Weighted-Average Assumption for Valuations of Class B Pre-Funded Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficienciesWeightedAverageAssumptionForValuationsOfClassBPreFundedWarrantsDetails</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Weighted-Average Assumption for Valuations of Class B Pre-Funded Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>40603 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Deficiency Triggered by Charter Revision (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficienciesDeficiencyTriggeredByCharterRevisionDetails</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Deficiency Triggered by Charter Revision (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>40604 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Derivative Liability Associated with Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficienciesDerivativeLiabilityAssociatedWithStockOptionsDetails</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Derivative Liability Associated with Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>40605 - Disclosure - DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Weighted-Average Assumption for Valuations by Charter Revision (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureDerivativeLiabilitiesForAuthorizedShareDeficienciesWeightedAverageAssumptionForValuationsByCharterRevisionDetails</Role>
      <ShortName>DERIVATIVE LIABILITIES FOR AUTHORIZED SHARE DEFICIENCIES - Weighted-Average Assumption for Valuations by Charter Revision (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>40701 - Disclosure - SHAREHOLDERS' EQUITY - Changes in Authorized Capital Stock (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityChangesInAuthorizedCapitalStockDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Changes in Authorized Capital Stock (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>40702 - Disclosure - SHAREHOLDERS' EQUITY - May 2022 Registered Direct Offering (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityMay2022RegisteredDirectOfferingDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - May 2022 Registered Direct Offering (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>40703 - Disclosure - SHAREHOLDERS' EQUITY - 2022 Pre-Funded Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquity2022PreFundedWarrantsDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - 2022 Pre-Funded Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>40704 - Disclosure - SHAREHOLDERS' EQUITY - Required Shareholder Approval (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityRequiredShareholderApprovalDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Required Shareholder Approval (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>40705 - Disclosure - SHAREHOLDERS' EQUITY - Registration Rights Agreement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityRegistrationRightsAgreementDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Registration Rights Agreement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>40706 - Disclosure - SHAREHOLDERS' EQUITY - 2021 Underwritten Public Offering (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquity2021UnderwrittenPublicOfferingDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - 2021 Underwritten Public Offering (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>40707 - Disclosure - SHAREHOLDERS' EQUITY - 2021 Pre-Funded Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquity2021PreFundedWarrantsDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - 2021 Pre-Funded Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>40708 - Disclosure - SHAREHOLDERS' EQUITY - 2021 Registered Direct Offering (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquity2021RegisteredDirectOfferingDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - 2021 Registered Direct Offering (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>40709 - Disclosure - SHAREHOLDERS' EQUITY - Equity Distribution Agreement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityEquityDistributionAgreementDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Equity Distribution Agreement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>40710 - Disclosure - SHAREHOLDERS' EQUITY - LPC Purchase Agreement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityLpcPurchaseAgreementDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - LPC Purchase Agreement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>40711 - Disclosure - SHAREHOLDERS' EQUITY - Fiscal 2021 Equity Financing (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareholdersEquityFiscal2021EquityFinancingDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Fiscal 2021 Equity Financing (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>40801 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS - Stock Option Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsStockOptionPlansDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS - Stock Option Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>40802 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS - Stock Options Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsStockOptionsOutstandingDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS - Stock Options Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>40803 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS - Weighted Average Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsWeightedAverageAssumptionsDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS - Weighted Average Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>40804 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS - Share Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsShareBasedCompensationExpenseDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS - Share Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>40805 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS - Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsWarrantsDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS - Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>40806 - Disclosure - SHARE-BASED COMPENSATION AND WARRANTS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureShareBasedCompensationAndWarrantsAdditionalInformationDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION AND WARRANTS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>40901 - Disclosure - INCOME TAXES - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>INCOME TAXES - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>40902 - Disclosure - INCOME TAXES - Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureIncomeTaxesIncomeTaxExpenseDetails</Role>
      <ShortName>INCOME TAXES - Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>40903 - Disclosure - INCOME TAXES - Deferred Income Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureIncomeTaxesDeferredIncomeTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>INCOME TAXES - Deferred Income Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>41001 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureCommitmentsAndContingenciesDetails</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>41101 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureRelatedPartyTransactionsDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.rezolutebio.com/role/DisclosureRelatedPartyTransactions</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>41201 - Disclosure - SUPPLEMENTAL FINANCIAL INFORMATION - Property and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureSupplementalFinancialInformationPropertyAndEquipmentDetails</Role>
      <ShortName>SUPPLEMENTAL FINANCIAL INFORMATION - Property and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>41301 - Disclosure - NET LOSS PER SHARE - Schedule of basic and diluted net loss per share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNetLossPerShareScheduleOfBasicAndDilutedNetLossPerShareDetails</Role>
      <ShortName>NET LOSS PER SHARE - Schedule of basic and diluted net loss per share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>41302 - Disclosure - NET LOSS PER SHARE - Anti-dilutive (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureNetLossPerShareAntiDilutiveDetails</Role>
      <ShortName>NET LOSS PER SHARE - Anti-dilutive (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>41401 - Disclosure - FINANCIAL INSTRUMENTS AND SIGNIFICANT CONCENTRATIONS - Summary of Changes in the Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureFinancialInstrumentsAndSignificantConcentrationsSummaryOfChangesInFairValueDetails</Role>
      <ShortName>FINANCIAL INSTRUMENTS AND SIGNIFICANT CONCENTRATIONS - Summary of Changes in the Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="rzlt-20220630x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>41501 - Disclosure - SUBSEQUENT EVENTS - July 2022 Financing (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.rezolutebio.com/role/DisclosureSubsequentEventsJuly2022FinancingDetails</Role>
      <ShortName>SUBSEQUENT EVENTS - July 2022 Financing (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 16 fact(s) appearing in ix:hidden were eligible for transformation: dei:CurrentFiscalYearEndDate, rzlt:NumberOfConsecutiveBusinessDaysForSelectingThreeLowestClosingSalePrices, rzlt:NumberOfEmployees, rzlt:UnderwritersOptionPeriod, us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1, us-gaap:CommonStockSharesOutstanding, us-gaap:LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1, us-gaap:OperatingLeaseLiability, us-gaap:OperatingLeaseRightOfUseAsset, us-gaap:PreferredStockSharesOutstanding, us-gaap:PropertyPlantAndEquipmentUsefulLife, us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 -  rzlt-20220630x10k.htm 9</Log>
    <Log type="Warning">[ix-0514-Hidden-Fact-Not-Referenced] WARN: 5 fact(s) appearing in ix:hidden were not referenced by any -sec-ix-hidden style property: us-gaap:CommitmentsAndContingencies, us-gaap:DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration, us-gaap:FairValueRecurringBasisUnobservableInputReconciliationLiabilityGainLossStatementOfIncomeExtensibleList -  rzlt-20220630x10k.htm 9</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-K" original="rzlt-20220630x10k.htm">rzlt-20220630x10k.htm</File>
    <File>rzlt-20220630.xsd</File>
    <File>rzlt-20220630_cal.xml</File>
    <File>rzlt-20220630_def.xml</File>
    <File>rzlt-20220630_lab.xml</File>
    <File>rzlt-20220630_pre.xml</File>
    <File>rzlt-20220630xex10d22.htm</File>
    <File>rzlt-20220630xex10d23.htm</File>
    <File>rzlt-20220630xex21d1.htm</File>
    <File>rzlt-20220630xex23d1.htm</File>
    <File>rzlt-20220630xex31d1.htm</File>
    <File>rzlt-20220630xex32d1.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="624">http://fasb.org/us-gaap/2022</BaseTaxonomy>
    <BaseTaxonomy items="36">http://xbrl.sec.gov/dei/2022</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
