<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>169</ContextCount>
  <ElementCount>268</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>60</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>8</UnitCount>
  <MyReports>
    <Report instance="gnk-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://gencoshipping.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="gnk-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://gencoshipping.com/role/StatementCondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="gnk-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://gencoshipping.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="gnk-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://gencoshipping.com/role/StatementCondensedConsolidatedStatementsOfOperations</Role>
      <ShortName>Condensed Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>995200205 - Statement - Condensed Consolidated Statements of Operations (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/StatementCondensedConsolidatedStatementsOfOperationsParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>995200300 - Statement - Condensed Consolidated Statements of Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995200400 - Statement - Condensed Consolidated Statements of Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/StatementCondensedConsolidatedStatementsOfEquity</Role>
      <ShortName>Condensed Consolidated Statements of Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>995200405 - Statement - Condensed Consolidated Statements of Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/StatementCondensedConsolidatedStatementsOfEquityParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Equity (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995200500 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/StatementCondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995210101 - Disclosure - GENERAL INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureGeneralInformation</Role>
      <ShortName>GENERAL INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995210201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995210301 - Disclosure - SEGMENT REPORTING</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSegmentReporting</Role>
      <ShortName>SEGMENT REPORTING</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995210401 - Disclosure - CASH FLOW INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureCashFlowInformation</Role>
      <ShortName>CASH FLOW INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995210501 - Disclosure - VESSEL ACQUISITIONS AND DISPOSITIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureVesselAcquisitionsAndDispositions</Role>
      <ShortName>VESSEL ACQUISITIONS AND DISPOSITIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995210601 - Disclosure - NET EARNINGS (LOSS) PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureNetEarningsLossPerShare</Role>
      <ShortName>NET EARNINGS (LOSS) PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995210701 - Disclosure - RELATED PARTY TRANSACTIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>RELATED PARTY TRANSACTIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995210801 - Disclosure - DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebt</Role>
      <ShortName>DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995210901 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureFairValueOfFinancialInstruments</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995211001 - Disclosure - ACCOUNTS PAYABLE AND ACCRUED EXPENSES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureAccountsPayableAndAccruedExpenses</Role>
      <ShortName>ACCOUNTS PAYABLE AND ACCRUED EXPENSES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995211101 - Disclosure - VOYAGE REVENUES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureVoyageRevenues</Role>
      <ShortName>VOYAGE REVENUES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995211201 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureLeases</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995211301 - Disclosure - STOCK-BASED COMPENSATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureStockBasedCompensation</Role>
      <ShortName>STOCK-BASED COMPENSATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995211401 - Disclosure - LEGAL PROCEEDINGS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureLegalProceedings</Role>
      <ShortName>LEGAL PROCEEDINGS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995211501 - Disclosure - SUBSEQUENT EVENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>SUBSEQUENT EVENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.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>25</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.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>26</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>99920202 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>99930303 - Disclosure - SEGMENT REPORTING (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSegmentReportingTables</Role>
      <ShortName>SEGMENT REPORTING (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureSegmentReporting</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>99930403 - Disclosure - CASH FLOW INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureCashFlowInformationTables</Role>
      <ShortName>CASH FLOW INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureCashFlowInformation</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>99930603 - Disclosure - NET EARNINGS (LOSS) PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureNetEarningsLossPerShareTables</Role>
      <ShortName>NET EARNINGS (LOSS) PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureNetEarningsLossPerShare</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>99930803 - Disclosure - DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebtTables</Role>
      <ShortName>DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureDebt</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>99930903 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureFairValueOfFinancialInstrumentsTables</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureFairValueOfFinancialInstruments</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>99931003 - Disclosure - ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureAccountsPayableAndAccruedExpensesTables</Role>
      <ShortName>ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureAccountsPayableAndAccruedExpenses</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>99931103 - Disclosure - VOYAGE REVENUES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureVoyageRevenuesTables</Role>
      <ShortName>VOYAGE REVENUES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureVoyageRevenues</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>99931303 - Disclosure - STOCK-BASED COMPENSATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureStockBasedCompensationTables</Role>
      <ShortName>STOCK-BASED COMPENSATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureStockBasedCompensation</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>99940101 - Disclosure - GENERAL INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureGeneralInformationDetails</Role>
      <ShortName>GENERAL INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureGeneralInformation</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>99940201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Bunker swaps and Forward Purchase Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPoliciesBunkerSwapsAndForwardPurchaseAgreementsDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Bunker swaps and Forward Purchase Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>99940202 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Voyage expense recognition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPoliciesVoyageExpenseRecognitionDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Voyage expense recognition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>99940203 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Impairment of vessel assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPoliciesImpairmentOfVesselAssetsDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Impairment of vessel assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>99940204 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Net gain on sale of vessels (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPoliciesNetGainOnSaleOfVesselsDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Net gain on sale of vessels (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>99940205 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Other Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSummaryOfSignificantAccountingPoliciesOtherExpenseDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Other Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>99940301 - Disclosure - SEGMENT REPORTING (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSegmentReportingDetails</Role>
      <ShortName>SEGMENT REPORTING (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureSegmentReportingTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>99940401 - Disclosure - CASH FLOW INFORMATION - Non-cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureCashFlowInformationNonCashDetails</Role>
      <ShortName>CASH FLOW INFORMATION - Non-cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>99940402 - Disclosure - CASH FLOW INFORMATION - Stock-Based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureCashFlowInformationStockBasedCompensationDetails</Role>
      <ShortName>CASH FLOW INFORMATION - Stock-Based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>99940403 - Disclosure - CASH FLOW INFORMATION - Lease payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureCashFlowInformationLeasePaymentsDetails</Role>
      <ShortName>CASH FLOW INFORMATION - Lease payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>99940501 - Disclosure - VESSEL ACQUISITIONS AND DISPOSITIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureVesselAcquisitionsAndDispositionsDetails</Role>
      <ShortName>VESSEL ACQUISITIONS AND DISPOSITIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureVesselAcquisitionsAndDispositions</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>99940601 - Disclosure - NET EARNINGS (LOSS) PER SHARE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureNetEarningsLossPerShareDetails</Role>
      <ShortName>NET EARNINGS (LOSS) PER SHARE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureNetEarningsLossPerShareTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>99940701 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureRelatedPartyTransactionsDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureRelatedPartyTransactions</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>99940801 - Disclosure - DEBT - Components of Long-term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebtComponentsOfLongTermDebtDetails</Role>
      <ShortName>DEBT - Components of Long-term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>99940802 - Disclosure - Debt - 680 Revolver (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebt680RevolverDetails</Role>
      <ShortName>Debt - 680 Revolver (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>99940803 - Disclosure - DEBT - 600 Revolver (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebt600RevolverDetails</Role>
      <ShortName>DEBT - 600 Revolver (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>99940805 - Disclosure - DEBT - 500 Revolver (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebt500RevolverDetails</Role>
      <ShortName>DEBT - 500 Revolver (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>99940807 - Disclosure - DEBT - Interest Rates (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureDebtInterestRatesDetails</Role>
      <ShortName>DEBT - Interest Rates (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>99940901 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS - RECURRING (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureFairValueOfFinancialInstrumentsRecurringDetails</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS - RECURRING (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>99940902 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS - NONRECURRING (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureFairValueOfFinancialInstrumentsNonrecurringDetails</Role>
      <ShortName>FAIR VALUE OF FINANCIAL INSTRUMENTS - NONRECURRING (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>99941001 - Disclosure - ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureAccountsPayableAndAccruedExpensesDetails</Role>
      <ShortName>ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureAccountsPayableAndAccruedExpensesTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>99941101 - Disclosure - VOYAGE REVENUES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureVoyageRevenuesDetails</Role>
      <ShortName>VOYAGE REVENUES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureVoyageRevenuesTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>99941201 - Disclosure - LEASES - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureLeasesNarrativeDetails</Role>
      <ShortName>LEASES - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>99941301 - Disclosure - STOCK-BASED COMPENSATION - 2015 EIP Stock Options and Other (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureStockBasedCompensation2015EipStockOptionsAndOtherDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - 2015 EIP Stock Options and Other (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>99941302 - Disclosure - STOCK-BASED COMPENSATION - 2015 EIP Restricted Stock Units (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureStockBasedCompensation2015EipRestrictedStockUnitsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - 2015 EIP Restricted Stock Units (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>99941303 - Disclosure - STOCK-BASED COMPENSATION - 2015 EIP Performance-Based Restricted Stock Units (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureStockBasedCompensation2015EipPerformanceBasedRestrictedStockUnitsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - 2015 EIP Performance-Based Restricted Stock Units (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="gnk-20260331x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>99941501 - Disclosure - SUBSEQUENT EVENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://gencoshipping.com/role/DisclosureSubsequentEventsDetails</Role>
      <ShortName>SUBSEQUENT EVENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://gencoshipping.com/role/DisclosureSubsequentEvents</ParentRole>
      <Position>62</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>gnk-20260331.xsd</File>
    <File>gnk-20260331_cal.xml</File>
    <File>gnk-20260331_def.xml</File>
    <File>gnk-20260331_lab.xml</File>
    <File>gnk-20260331_pre.xml</File>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="gnk-20260331x10q.htm">gnk-20260331x10q.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="443">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="33">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
