<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>484</ContextCount>
  <ElementCount>522</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>139</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>15</UnitCount>
  <MyReports>
    <Report instance="tmb-20251231x40f.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.fortunasilver.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - Consolidated Statements of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>Consolidated Statements of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00200 - Statement - Consolidated Statements of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00205 - Statement - Consolidated Statements of Comprehensive Income (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeParenthetical</Role>
      <ShortName>Consolidated Statements of Comprehensive Income (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00300 - Statement - Consolidated Statements of Financial Position</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/StatementConsolidatedStatementsOfFinancialPosition</Role>
      <ShortName>Consolidated Statements of Financial Position</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="tmb-20251231x40f.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.fortunasilver.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00405 - Statement - Consolidated Statements of Cash Flows - Cash and Cash Equivalents</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/StatementConsolidatedStatementsOfCashFlowsCashAndCashEquivalents</Role>
      <ShortName>Consolidated Statements of Cash Flows - Cash and Cash Equivalents</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00500 - Statement - Consolidated Statements of Changes in Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/StatementConsolidatedStatementsOfChangesInEquity</Role>
      <ShortName>Consolidated Statements of Changes in Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>10101 - Disclosure - NATURE OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureNatureOfOperations</Role>
      <ShortName>NATURE OF OPERATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10201 - Disclosure - BASIS OF PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureBasisOfPresentation</Role>
      <ShortName>BASIS OF PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10301 - Disclosure - MATERIAL ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPolicies</Role>
      <ShortName>MATERIAL ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10401 - Disclosure - USE OF ESTIMATES, ASSUMPTIONS, AND JUDGEMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureUseOfEstimatesAssumptionsAndJudgements</Role>
      <ShortName>USE OF ESTIMATES, ASSUMPTIONS, AND JUDGEMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10501 - Disclosure - TRADE AND OTHER RECEIVABLES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureTradeAndOtherReceivables</Role>
      <ShortName>TRADE AND OTHER RECEIVABLES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10601 - Disclosure - INVENTORIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureInventories</Role>
      <ShortName>INVENTORIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10701 - Disclosure - OTHER CURRENT ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherCurrentAssets</Role>
      <ShortName>OTHER CURRENT ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>10801 - Disclosure - MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipment</Role>
      <ShortName>MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>10901 - Disclosure - OTHER NON-CURRENT ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentAssets</Role>
      <ShortName>OTHER NON-CURRENT ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>11001 - Disclosure - TRADE AND OTHER PAYABLES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureTradeAndOtherPayables</Role>
      <ShortName>TRADE AND OTHER PAYABLES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11101 - Disclosure - RELATED PARTY TRANSACTIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>RELATED PARTY TRANSACTIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11201 - Disclosure - LEASE OBLIGATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureLeaseObligations</Role>
      <ShortName>LEASE OBLIGATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11301 - Disclosure - DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDebt</Role>
      <ShortName>DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>11401 - Disclosure - OTHER NON-CURRENT LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentLiabilities</Role>
      <ShortName>OTHER NON-CURRENT LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>11501 - Disclosure - CLOSURE AND RECLAMATION PROVISIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisions</Role>
      <ShortName>CLOSURE AND RECLAMATION PROVISIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>11601 - Disclosure - SHARE-BASED PAYMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureShareBasedPayments</Role>
      <ShortName>SHARE-BASED PAYMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>11701 - Disclosure - SHARE CAPITAL</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureShareCapital</Role>
      <ShortName>SHARE CAPITAL</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>11801 - Disclosure - EARNINGS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureEarningsPerShare</Role>
      <ShortName>EARNINGS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>11901 - Disclosure - SALES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSales</Role>
      <ShortName>SALES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>12001 - Disclosure - COST OF SALES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureCostOfSales</Role>
      <ShortName>COST OF SALES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>12101 - Disclosure - GENERAL AND ADMINISTRATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureGeneralAndAdministration</Role>
      <ShortName>GENERAL AND ADMINISTRATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>12201 - Disclosure - OTHER EXPENSES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherExpenses</Role>
      <ShortName>OTHER EXPENSES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>12301 - Disclosure - INTEREST AND FINANCE COSTS, NET</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureInterestAndFinanceCostsNet</Role>
      <ShortName>INTEREST AND FINANCE COSTS, NET</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>12401 - Disclosure - INCOME TAX</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTax</Role>
      <ShortName>INCOME TAX</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>12501 - Disclosure - DISCONTINUED OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperations</Role>
      <ShortName>DISCONTINUED OPERATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>12601 - Disclosure - SEGMENTED INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSegmentedInformation</Role>
      <ShortName>SEGMENTED INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>12701 - Disclosure - FAIR VALUE MEASUREMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureFairValueMeasurements</Role>
      <ShortName>FAIR VALUE MEASUREMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>12801 - Disclosure - MANAGEMENT OF FINANCIAL RISK</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRisk</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>12901 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformation</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>13001 - Disclosure - NON-CONTROLLING INTERESTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureNonControllingInterests</Role>
      <ShortName>NON-CONTROLLING INTERESTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>13101 - Disclosure - CONTINGENCIES AND CAPITAL COMMITMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureContingenciesAndCapitalCommitments</Role>
      <ShortName>CONTINGENCIES AND CAPITAL COMMITMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>13201 - Disclosure - REVERSAL OF IMPAIRMENT CHARGE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureReversalOfImpairmentCharge</Role>
      <ShortName>REVERSAL OF IMPAIRMENT CHARGE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>20302 - Disclosure - MATERIAL ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesPolicies</Role>
      <ShortName>MATERIAL ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>20402 - Disclosure - USE OF ESTIMATES, ASSUMPTIONS, AND JUDGEMENTS (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureUseOfEstimatesAssumptionsAndJudgementsPolicies</Role>
      <ShortName>USE OF ESTIMATES, ASSUMPTIONS, AND JUDGEMENTS (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>30303 - Disclosure - MATERIAL ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesTables</Role>
      <ShortName>MATERIAL ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPolicies</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>30503 - Disclosure - TRADE AND OTHER RECEIVABLES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureTradeAndOtherReceivablesTables</Role>
      <ShortName>TRADE AND OTHER RECEIVABLES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureTradeAndOtherReceivables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>30603 - Disclosure - INVENTORIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureInventoriesTables</Role>
      <ShortName>INVENTORIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureInventories</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>30703 - Disclosure - OTHER CURRENT ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherCurrentAssetsTables</Role>
      <ShortName>OTHER CURRENT ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherCurrentAssets</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>30803 - Disclosure - MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipmentTables</Role>
      <ShortName>MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipment</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>30903 - Disclosure - OTHER NON-CURRENT ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentAssetsTables</Role>
      <ShortName>OTHER NON-CURRENT ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentAssets</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>31003 - Disclosure - TRADE AND OTHER PAYABLES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureTradeAndOtherPayablesTables</Role>
      <ShortName>TRADE AND OTHER PAYABLES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureTradeAndOtherPayables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>31103 - Disclosure - RELATED PARTY TRANSACTIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureRelatedPartyTransactionsTables</Role>
      <ShortName>RELATED PARTY TRANSACTIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureRelatedPartyTransactions</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>31203 - Disclosure - LEASE OBLIGATIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureLeaseObligationsTables</Role>
      <ShortName>LEASE OBLIGATIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureLeaseObligations</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>31303 - Disclosure - DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDebtTables</Role>
      <ShortName>DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureDebt</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>31403 - Disclosure - OTHER NON-CURRENT LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentLiabilitiesTables</Role>
      <ShortName>OTHER NON-CURRENT LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentLiabilities</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>31503 - Disclosure - CLOSURE AND RECLAMATION PROVISIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisionsTables</Role>
      <ShortName>CLOSURE AND RECLAMATION PROVISIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisions</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>31603 - Disclosure - SHARE-BASED PAYMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureShareBasedPaymentsTables</Role>
      <ShortName>SHARE-BASED PAYMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureShareBasedPayments</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>31803 - Disclosure - EARNINGS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureEarningsPerShareTables</Role>
      <ShortName>EARNINGS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureEarningsPerShare</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>31903 - Disclosure - SALES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSalesTables</Role>
      <ShortName>SALES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSales</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>32003 - Disclosure - COST OF SALES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureCostOfSalesTables</Role>
      <ShortName>COST OF SALES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureCostOfSales</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>32103 - Disclosure - GENERAL AND ADMINISTRATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureGeneralAndAdministrationTables</Role>
      <ShortName>GENERAL AND ADMINISTRATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureGeneralAndAdministration</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>32203 - Disclosure - OTHER EXPENSES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherExpensesTables</Role>
      <ShortName>OTHER EXPENSES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherExpenses</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>32303 - Disclosure - INTEREST AND FINANCE COSTS, NET (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureInterestAndFinanceCostsNetTables</Role>
      <ShortName>INTEREST AND FINANCE COSTS, NET (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureInterestAndFinanceCostsNet</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>32403 - Disclosure - INCOME TAX (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</Role>
      <ShortName>INCOME TAX (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTax</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>32503 - Disclosure - DISCONTINUED OPERATIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperationsTables</Role>
      <ShortName>DISCONTINUED OPERATIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperations</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>32603 - Disclosure - SEGMENTED INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSegmentedInformationTables</Role>
      <ShortName>SEGMENTED INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSegmentedInformation</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>32703 - Disclosure - FAIR VALUE MEASUREMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>FAIR VALUE MEASUREMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureFairValueMeasurements</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>32803 - Disclosure - MANAGEMENT OF FINANCIAL RISK (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskTables</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRisk</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>32903 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationTables</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformation</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>33003 - Disclosure - NON-CONTROLLING INTERESTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureNonControllingInterestsTables</Role>
      <ShortName>NON-CONTROLLING INTERESTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureNonControllingInterests</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>40101 - Disclosure - NATURE OF OPERATIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureNatureOfOperationsDetails</Role>
      <ShortName>NATURE OF OPERATIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureNatureOfOperations</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>40301 - Disclosure - MATERIAL ACCOUNTING POLICIES (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesNarrativeDetails</Role>
      <ShortName>MATERIAL ACCOUNTING POLICIES (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesTables</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>40302 - Disclosure - MATERIAL ACCOUNTING POLICIES (Disclosure of subsidiaries) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesDisclosureOfSubsidiariesDetails</Role>
      <ShortName>MATERIAL ACCOUNTING POLICIES (Disclosure of subsidiaries) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>40303 - Disclosure - MATERIAL ACCOUNTING POLICIES (Schedule related to property, plant and equipment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesScheduleRelatedToPropertyPlantAndEquipmentDetails</Role>
      <ShortName>MATERIAL ACCOUNTING POLICIES (Schedule related to property, plant and equipment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMaterialAccountingPoliciesTables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>40401 - Disclosure - USE OF ESTIMATES, ASSUMPTIONS, AND JUDGEMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureUseOfEstimatesAssumptionsAndJudgementsDetails</Role>
      <ShortName>USE OF ESTIMATES, ASSUMPTIONS, AND JUDGEMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureUseOfEstimatesAssumptionsAndJudgementsPolicies</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>40501 - Disclosure - TRADE AND OTHER RECEIVABLES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureTradeAndOtherReceivablesDetails</Role>
      <ShortName>TRADE AND OTHER RECEIVABLES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureTradeAndOtherReceivablesTables</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>40601 - Disclosure - INVENTORIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureInventoriesDetails</Role>
      <ShortName>INVENTORIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureInventoriesTables</ParentRole>
      <Position>75</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>40701 - Disclosure - OTHER CURRENT ASSETS - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherCurrentAssetsTabularDisclosureDetails</Role>
      <ShortName>OTHER CURRENT ASSETS - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>40702 - Disclosure - OTHER CURRENT ASSETS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherCurrentAssetsAdditionalInformationDetails</Role>
      <ShortName>OTHER CURRENT ASSETS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>40703 - Disclosure - OTHER CURRENT ASSETS - Investments in Equity Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherCurrentAssetsInvestmentsInEquitySecuritiesDetails</Role>
      <ShortName>OTHER CURRENT ASSETS - Investments in Equity Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>40801 - Disclosure - MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipmentNarrativeDetails</Role>
      <ShortName>MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipmentTables</ParentRole>
      <Position>79</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>40802 - Disclosure - MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT (Schedule Related to Property, Plant and Equipment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipmentScheduleRelatedToPropertyPlantAndEquipmentDetails</Role>
      <ShortName>MINERAL PROPERTIES AND PROPERTY, PLANT AND EQUIPMENT (Schedule Related to Property, Plant and Equipment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureMineralPropertiesAndPropertyPlantAndEquipmentTables</ParentRole>
      <Position>80</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>40901 - Disclosure - OTHER NON-CURRENT ASSETS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentAssetsDetails</Role>
      <ShortName>OTHER NON-CURRENT ASSETS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentAssetsTables</ParentRole>
      <Position>81</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>41001 - Disclosure - TRADE AND OTHER PAYABLES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureTradeAndOtherPayablesDetails</Role>
      <ShortName>TRADE AND OTHER PAYABLES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureTradeAndOtherPayablesTables</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>41101 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureRelatedPartyTransactionsDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureRelatedPartyTransactionsTables</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>41201 - Disclosure - LEASE OBLIGATIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureLeaseObligationsDetails</Role>
      <ShortName>LEASE OBLIGATIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureLeaseObligationsTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>41301 - Disclosure - DEBT - Movement in debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDebtMovementInDebtDetails</Role>
      <ShortName>DEBT - Movement in debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>41302 - Disclosure - DEBT - 2024 Convertible Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDebt2024ConvertibleNotesDetails</Role>
      <ShortName>DEBT - 2024 Convertible Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>41303 - Disclosure - DEBT - 2019 Convertible Debentures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDebt2019ConvertibleDebenturesDetails</Role>
      <ShortName>DEBT - 2019 Convertible Debentures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>41304 - Disclosure - DEBT - Credit Facilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDebtCreditFacilitiesDetails</Role>
      <ShortName>DEBT - Credit Facilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>41401 - Disclosure - OTHER NON-CURRENT LIABILITIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentLiabilitiesDetails</Role>
      <ShortName>OTHER NON-CURRENT LIABILITIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherNonCurrentLiabilitiesTables</ParentRole>
      <Position>89</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>41501 - Disclosure - CLOSURE AND RECLAMATION PROVISIONS (Schedule of Closure and Rehabilitation Provisions) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisionsScheduleOfClosureAndRehabilitationProvisionsDetails</Role>
      <ShortName>CLOSURE AND RECLAMATION PROVISIONS (Schedule of Closure and Rehabilitation Provisions) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisionsTables</ParentRole>
      <Position>90</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>41502 - Disclosure - CLOSURE AND RECLAMATION PROVISIONS (Schedule of Estimates Used in Closure and Rehabilitation Provisions) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisionsScheduleOfEstimatesUsedInClosureAndRehabilitationProvisionsDetails</Role>
      <ShortName>CLOSURE AND RECLAMATION PROVISIONS (Schedule of Estimates Used in Closure and Rehabilitation Provisions) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureClosureAndReclamationProvisionsTables</ParentRole>
      <Position>91</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>41601 - Disclosure - SHARE-BASED PAYMENTS (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureShareBasedPaymentsNarrativeDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureShareBasedPaymentsTables</ParentRole>
      <Position>92</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>41602 - Disclosure - SHARE-BASED PAYMENTS (Schedule of Outstanding Units Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureShareBasedPaymentsScheduleOfOutstandingUnitsActivityDetails</Role>
      <ShortName>SHARE-BASED PAYMENTS (Schedule of Outstanding Units Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureShareBasedPaymentsTables</ParentRole>
      <Position>93</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>41701 - Disclosure - SHARE CAPITAL (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureShareCapitalDetails</Role>
      <ShortName>SHARE CAPITAL (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureShareCapital</ParentRole>
      <Position>94</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>41801 - Disclosure - EARNINGS PER SHARE - Basic (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureEarningsPerShareBasicDetails</Role>
      <ShortName>EARNINGS PER SHARE - Basic (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>41802 - Disclosure - EARNINGS PER SHARE - Diluted (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureEarningsPerShareDilutedDetails</Role>
      <ShortName>EARNINGS PER SHARE - Diluted (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>41803 - Disclosure - EARNINGS PER SHARE - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureEarningsPerShareAdditionalInformationDetails</Role>
      <ShortName>EARNINGS PER SHARE - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>41804 - Disclosure - EARNINGS PER SHARE - Antidilutive Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureEarningsPerShareAntidilutiveInstrumentsDetails</Role>
      <ShortName>EARNINGS PER SHARE - Antidilutive Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>41901 - Disclosure - SALES (Schedule of Sales by Product and Geographical Area) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSalesScheduleOfSalesByProductAndGeographicalAreaDetails</Role>
      <ShortName>SALES (Schedule of Sales by Product and Geographical Area) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSalesTables</ParentRole>
      <Position>99</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>41902 - Disclosure - SALES (Schedule of Sales by Major Customer) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSalesScheduleOfSalesByMajorCustomerDetails</Role>
      <ShortName>SALES (Schedule of Sales by Major Customer) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSalesTables</ParentRole>
      <Position>100</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>42001 - Disclosure - COST OF SALES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureCostOfSalesDetails</Role>
      <ShortName>COST OF SALES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureCostOfSalesTables</ParentRole>
      <Position>101</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>42101 - Disclosure - GENERAL AND ADMINISTRATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureGeneralAndAdministrationDetails</Role>
      <ShortName>GENERAL AND ADMINISTRATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureGeneralAndAdministrationTables</ParentRole>
      <Position>102</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>42201 - Disclosure - OTHER EXPENSES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureOtherExpensesDetails</Role>
      <ShortName>OTHER EXPENSES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureOtherExpensesTables</ParentRole>
      <Position>103</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>42301 - Disclosure - INTEREST AND FINANCE COSTS, NET (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureInterestAndFinanceCostsNetDetails</Role>
      <ShortName>INTEREST AND FINANCE COSTS, NET (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureInterestAndFinanceCostsNetTables</ParentRole>
      <Position>104</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>42401 - Disclosure - INCOME TAX (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxNarrativeDetails</Role>
      <ShortName>INCOME TAX (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</ParentRole>
      <Position>105</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>42402 - Disclosure - INCOME TAX (Schedule of Income Tax Reconciliation) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxScheduleOfIncomeTaxReconciliationDetails</Role>
      <ShortName>INCOME TAX (Schedule of Income Tax Reconciliation) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</ParentRole>
      <Position>106</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>42403 - Disclosure - INCOME TAX (Schedule of Current and Deferred Taxes) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxScheduleOfCurrentAndDeferredTaxesDetails</Role>
      <ShortName>INCOME TAX (Schedule of Current and Deferred Taxes) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</ParentRole>
      <Position>107</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>42404 - Disclosure - INCOME TAX (Schedule of Deferred Tax Assets and Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxScheduleOfDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>INCOME TAX (Schedule of Deferred Tax Assets and Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</ParentRole>
      <Position>108</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>42405 - Disclosure - INCOME TAX (Schedule of Unrecognized Deductible Temporary Difference and Unused Tax Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxScheduleOfUnrecognizedDeductibleTemporaryDifferenceAndUnusedTaxLossesDetails</Role>
      <ShortName>INCOME TAX (Schedule of Unrecognized Deductible Temporary Difference and Unused Tax Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</ParentRole>
      <Position>109</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>42406 - Disclosure - INCOME TAX (Schedule of Tax Losses Expiry Dates) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureIncomeTaxScheduleOfTaxLossesExpiryDatesDetails</Role>
      <ShortName>INCOME TAX (Schedule of Tax Losses Expiry Dates) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureIncomeTaxTables</ParentRole>
      <Position>110</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>42501 - Disclosure - DISCONTINUED OPERATIONS - Results (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperationsResultsDetails</Role>
      <ShortName>DISCONTINUED OPERATIONS - Results (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>42502 - Disclosure - DISCONTINUED OPERATIONS - Effect of Disposal (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperationsEffectOfDisposalDetails</Role>
      <ShortName>DISCONTINUED OPERATIONS - Effect of Disposal (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>42503 - Disclosure - DISCONTINUED OPERATIONS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperationsAdditionalInformationDetails</Role>
      <ShortName>DISCONTINUED OPERATIONS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>42504 - Disclosure - DISCONTINUED OPERATIONS - Cash Flows (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureDiscontinuedOperationsCashFlowsDetails</Role>
      <ShortName>DISCONTINUED OPERATIONS - Cash Flows (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>42601 - Disclosure - SEGMENTED INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSegmentedInformationDetails</Role>
      <ShortName>SEGMENTED INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSegmentedInformationTables</ParentRole>
      <Position>115</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>42701 - Disclosure - FAIR VALUE MEASUREMENTS (Schedule of financial assets and financial liabilities by category) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsScheduleOfFinancialAssetsAndFinancialLiabilitiesByCategoryDetails</Role>
      <ShortName>FAIR VALUE MEASUREMENTS (Schedule of financial assets and financial liabilities by category) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsTables</ParentRole>
      <Position>116</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>42702 - Disclosure - FAIR VALUE MEASUREMENTS (Schedule of fair values of financial assets and financial liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsScheduleOfFairValuesOfFinancialAssetsAndFinancialLiabilitiesDetails</Role>
      <ShortName>FAIR VALUE MEASUREMENTS (Schedule of fair values of financial assets and financial liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsTables</ParentRole>
      <Position>117</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>42703 - Disclosure - FAIR VALUE MEASUREMENTS (Schedule of financial assets and financial liabilities not already measured at fair value) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsScheduleOfFinancialAssetsAndFinancialLiabilitiesNotAlreadyMeasuredAtFairValueDetails</Role>
      <ShortName>FAIR VALUE MEASUREMENTS (Schedule of financial assets and financial liabilities not already measured at fair value) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureFairValueMeasurementsTables</ParentRole>
      <Position>118</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>42801 - Disclosure - MANAGEMENT OF FINANCIAL RISK (Schedule of Company's Maximum Exposure to Credit Risk) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskScheduleOfCompanySMaximumExposureToCreditRiskDetails</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK (Schedule of Company's Maximum Exposure to Credit Risk) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskTables</ParentRole>
      <Position>119</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>42802 - Disclosure - MANAGEMENT OF FINANCIAL RISK (Schedule of Company's Liquidity Risk) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskScheduleOfCompanySLiquidityRiskDetails</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK (Schedule of Company's Liquidity Risk) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskTables</ParentRole>
      <Position>120</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>42803 - Disclosure - MANAGEMENT OF FINANCIAL RISK (Disclosure of Nature and Extent Arising from Financial Instruments - Currency Risk) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskDisclosureOfNatureAndExtentArisingFromFinancialInstrumentsCurrencyRiskDetails</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK (Disclosure of Nature and Extent Arising from Financial Instruments - Currency Risk) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskTables</ParentRole>
      <Position>121</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>42804 - Disclosure - MANAGEMENT OF FINANCIAL RISK (Disclosure of Nature and Extent Arising from Financial Instruments - Commodity Price Risk) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskDisclosureOfNatureAndExtentArisingFromFinancialInstrumentsCommodityPriceRiskDetails</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK (Disclosure of Nature and Extent Arising from Financial Instruments - Commodity Price Risk) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskTables</ParentRole>
      <Position>122</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>42805 - Disclosure - MANAGEMENT OF FINANCIAL RISK (Capital Management) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskCapitalManagementDetails</Role>
      <ShortName>MANAGEMENT OF FINANCIAL RISK (Capital Management) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureManagementOfFinancialRiskTables</ParentRole>
      <Position>123</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>42901 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION (Schedule of changes in working capital) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationScheduleOfChangesInWorkingCapitalDetails</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION (Schedule of changes in working capital) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationTables</ParentRole>
      <Position>124</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>42902 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION (Schedule of changes in liabilities arising from financing activities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationScheduleOfChangesInLiabilitiesArisingFromFinancingActivitiesDetails</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION (Schedule of changes in liabilities arising from financing activities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationTables</ParentRole>
      <Position>125</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>42903 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION (Schedule of significant non-cash financing and investing transactions) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationScheduleOfSignificantNonCashFinancingAndInvestingTransactionsDetails</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION (Schedule of significant non-cash financing and investing transactions) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureSupplementalCashFlowInformationTables</ParentRole>
      <Position>126</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R127.htm</HtmlFileName>
      <LongName>43001 - Disclosure - NON-CONTROLLING INTERESTS - General Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureNonControllingInterestsGeneralInformationDetails</Role>
      <ShortName>NON-CONTROLLING INTERESTS - General Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>127</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R128.htm</HtmlFileName>
      <LongName>43002 - Disclosure - NON-CONTROLLING INTERESTS - Summarized Financial Statements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureNonControllingInterestsSummarizedFinancialStatementsDetails</Role>
      <ShortName>NON-CONTROLLING INTERESTS - Summarized Financial Statements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>128</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R129.htm</HtmlFileName>
      <LongName>43101 - Disclosure - CONTINGENCIES AND CAPITAL COMMITMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureContingenciesAndCapitalCommitmentsDetails</Role>
      <ShortName>CONTINGENCIES AND CAPITAL COMMITMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureContingenciesAndCapitalCommitments</ParentRole>
      <Position>129</Position>
    </Report>
    <Report instance="tmb-20251231x40f.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R130.htm</HtmlFileName>
      <LongName>43201 - Disclosure - REVERSAL OF IMPAIRMENT CHARGE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fortunasilver.com/role/DisclosureReversalOfImpairmentChargeDetails</Role>
      <ShortName>REVERSAL OF IMPAIRMENT CHARGE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fortunasilver.com/role/DisclosureReversalOfImpairmentCharge</ParentRole>
      <Position>130</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>tmb-20251231.xsd</File>
    <File>tmb-20251231_cal.xml</File>
    <File>tmb-20251231_def.xml</File>
    <File>tmb-20251231_lab.xml</File>
    <File>tmb-20251231_pre.xml</File>
    <File doctype="40-F" isDefinitelyFs="true" isIfrs="true" original="tmb-20251231x40f.htm">tmb-20251231x40f.htm</File>
    <File doctype="40-F" isDefinitelyFs="true" isIfrs="true" original="tmb-20251231xex99d2.htm">tmb-20251231xex99d2.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>tmb-20251231xex99d2001.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="44">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="1166">https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
