<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>73</ContextCount>
  <ElementCount>178</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>22</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>995200090 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995200100 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/StatementCondensedConsolidatedBalanceSheets</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>995200105 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>995200200 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/StatementCondensedConsolidatedStatementsOfOperations</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>995200300 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/StatementCondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>995200305 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995200400 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/StatementCondensedConsolidatedStatementsOfShareholdersEquity</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>995210101 - Disclosure - NATURE OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureNatureOfOperations</Role>
      <ShortName>NATURE OF OPERATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995210201 - Disclosure - BASIS OF ACCOUNTING AND PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureBasisOfAccountingAndPresentation</Role>
      <ShortName>BASIS OF ACCOUNTING AND PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995210301 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureFairValueOfFinancialInstruments</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995210401 - Disclosure - RELATED PARTY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureRelatedParty</Role>
      <ShortName>RELATED PARTY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995210501 - Disclosure - WYOMING ENERGY AUTHORITY GRANT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureWyomingEnergyAuthorityGrant</Role>
      <ShortName>WYOMING ENERGY AUTHORITY GRANT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995210601 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureLeases</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995210701 - Disclosure - SHAREHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureShareholdersEquity</Role>
      <ShortName>SHAREHOLDERS' EQUITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995210801 - Disclosure - COMMITMENTS AND CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995210901 - Disclosure - GEOGRAPHIC AND SEGMENT INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureGeographicAndSegmentInformation</Role>
      <ShortName>GEOGRAPHIC AND SEGMENT INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995211001 - Disclosure - SUBSEQUENT EVENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>SUBSEQUENT EVENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>99920202 - Disclosure - BASIS OF ACCOUNTING AND PRESENTATION (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureBasisOfAccountingAndPresentationPolicies</Role>
      <ShortName>BASIS OF ACCOUNTING AND PRESENTATION (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>99930303 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureFairValueOfFinancialInstrumentsTables</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureFairValueOfFinancialInstruments</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>99930403 - Disclosure - RELATED PARTY (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureRelatedPartyTables</Role>
      <ShortName>RELATED PARTY (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureRelatedParty</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>99930603 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureLeasesTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureLeases</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>99930703 - Disclosure - SHAREHOLDERS' EQUITY (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureShareholdersEquityTables</Role>
      <ShortName>SHAREHOLDERS' EQUITY (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureShareholdersEquity</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>99940101 - Disclosure - NATURE OF OPERATIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureNatureOfOperationsDetails</Role>
      <ShortName>NATURE OF OPERATIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureNatureOfOperations</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>99940201 - Disclosure - BASIS OF ACCOUNTING AND PRESENTATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureBasisOfAccountingAndPresentationDetails</Role>
      <ShortName>BASIS OF ACCOUNTING AND PRESENTATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureBasisOfAccountingAndPresentationPolicies</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>99940301 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureFairValueOfFinancialInstrumentsDetails</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureFairValueOfFinancialInstrumentsTables</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>99940401 - Disclosure - RELATED PARTY (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureRelatedPartyDetails</Role>
      <ShortName>RELATED PARTY (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureRelatedPartyTables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>99940402 - Disclosure - RELATED PARTY - Schedule of Related Party Receivables - General Atomics (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureRelatedPartyScheduleOfRelatedPartyReceivablesGeneralAtomicsDetails</Role>
      <ShortName>RELATED PARTY - Schedule of Related Party Receivables - General Atomics (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>99940501 - Disclosure - WYOMING ENERGY AUTHORITY GRANT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureWyomingEnergyAuthorityGrantDetails</Role>
      <ShortName>WYOMING ENERGY AUTHORITY GRANT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureWyomingEnergyAuthorityGrant</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>99940601 - Disclosure - LEASES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureLeasesDetails</Role>
      <ShortName>LEASES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureLeasesTables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>99940602 - Disclosure - LEASES - Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureLeasesLeasePaymentsDetails</Role>
      <ShortName>LEASES - Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>99940701 - Disclosure - SHAREHOLDERS' EQUITY (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureShareholdersEquityDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureShareholdersEquityTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>99940702 - Disclosure - SHAREHOLDERS' EQUITY - Stock option activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureShareholdersEquityStockOptionActivityDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Stock option activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>99940703 - Disclosure - SHAREHOLDERS' EQUITY - Intrinsic value and weighted average remaining life for stock (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureShareholdersEquityIntrinsicValueAndWeightedAverageRemainingLifeForStockDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - Intrinsic value and weighted average remaining life for stock (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>99940704 - Disclosure - SHAREHOLDERS' EQUITY - 2026 Rights Offering (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureShareholdersEquity2026RightsOfferingDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY - 2026 Rights Offering (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>99940801 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureCommitmentsAndContingenciesDetails</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="reemf-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>99940901 - Disclosure - GEOGRAPHIC AND SEGMENT INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://rarelelementresources.com/role/DisclosureGeographicAndSegmentInformationDetails</Role>
      <ShortName>GEOGRAPHIC AND SEGMENT INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://rarelelementresources.com/role/DisclosureGeographicAndSegmentInformation</ParentRole>
      <Position>38</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>reemf-20260331.xsd</File>
    <File>reemf-20260331_cal.xml</File>
    <File>reemf-20260331_def.xml</File>
    <File>reemf-20260331_lab.xml</File>
    <File>reemf-20260331_pre.xml</File>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="reemf-20260331x10q.htm">reemf-20260331x10q.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>reemf-20260331x10q001.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="242">http://fasb.org/us-gaap/2024</BaseTaxonomy>
    <BaseTaxonomy items="27">http://xbrl.sec.gov/dei/2024</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2024</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
