<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>492</ContextCount>
  <ElementCount>539</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>173</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DocumentandEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952151 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952152 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952153 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952155 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952156 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952157 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952158 - Statement - CSC HOLDINGS - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CSCHOLDINGSCONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CSC HOLDINGS - CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952159 - Statement - CSC HOLDINGS - CONSOLIDATED BALANCE SHEETS (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CSCHOLDINGSCONSOLIDATEDBALANCESHEETSParentheticals</Role>
      <ShortName>CSC HOLDINGS - CONSOLIDATED BALANCE SHEETS (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952160 - Statement - CSC HOLDINGS - CONSOLIDATED STATEMENT OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CSCHOLDINGSCONSOLIDATEDSTATEMENTOFOPERATIONS</Role>
      <ShortName>CSC HOLDINGS - CONSOLIDATED STATEMENT OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952162 - Statement - CSC HOLDINGS - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CSCHOLDINGSCONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS</Role>
      <ShortName>CSC HOLDINGS - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952163 - Statement - CSC HOLDINGS - CONSOLIDATED STATEMENT OF MEMBER'S EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CSCHOLDINGSCONSOLIDATEDSTATEMENTOFMEMBERSEQUITY</Role>
      <ShortName>CSC HOLDINGS - CONSOLIDATED STATEMENT OF MEMBER'S EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952164 - Statement - CSC HOLDINGS - CONSOLIDATED STATEMENT OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CSCHOLDINGSCONSOLIDATEDSTATEMENTOFCASHFLOWS</Role>
      <ShortName>CSC HOLDINGS - CONSOLIDATED STATEMENT OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - DESCRIPTION OF BUSINESS AND RELATED MATTERS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DESCRIPTIONOFBUSINESSANDRELATEDMATTERS</Role>
      <ShortName>DESCRIPTION OF BUSINESS AND RELATED MATTERS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - CHANGE IN ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CHANGEINACCOUNTINGPOLICIES</Role>
      <ShortName>CHANGE IN ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - ACCOUNTING STANDARDS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/ACCOUNTINGSTANDARDS</Role>
      <ShortName>ACCOUNTING STANDARDS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952170 - Disclosure - ALLOWANCE FOR DOUBTFUL ACCOUNTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/ALLOWANCEFORDOUBTFULACCOUNTS</Role>
      <ShortName>ALLOWANCE FOR DOUBTFUL ACCOUNTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9952171 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUPPLEMENTALCASHFLOWINFORMATION</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9952172 - Disclosure - RESTRUCTURING AND OTHER EXPENSE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/RESTRUCTURINGANDOTHEREXPENSE</Role>
      <ShortName>RESTRUCTURING AND OTHER EXPENSE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9952173 - Disclosure - PROPERTY, PLANT AND EQUIPMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/PROPERTYPLANTANDEQUIPMENT</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9952174 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/LEASES</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9952175 - Disclosure - INTANGIBLE ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTANGIBLEASSETS</Role>
      <ShortName>INTANGIBLE ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9952176 - Disclosure - DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBT</Role>
      <ShortName>DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9952177 - Disclosure - DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESS</Role>
      <ShortName>DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9952178 - Disclosure - FAIR VALUE MEASUREMENT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/FAIRVALUEMEASUREMENT</Role>
      <ShortName>FAIR VALUE MEASUREMENT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9952179 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXES</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9952180 - Disclosure - SHARE-BASED COMPENSATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SHAREBASEDCOMPENSATION</Role>
      <ShortName>SHARE-BASED COMPENSATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9952181 - Disclosure - AFFILIATE AND RELATED PARTY TRANSACTIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/AFFILIATEANDRELATEDPARTYTRANSACTIONS</Role>
      <ShortName>AFFILIATE AND RELATED PARTY TRANSACTIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9952182 - Disclosure - COMMITMENTS AND CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/COMMITMENTSANDCONTINGENCIES</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9952183 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9952184 - Disclosure - SEC Schedule, Article 12-04, Condensed Financial Information of Registrant</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SECScheduleArticle1204CondensedFinancialInformationofRegistrant</Role>
      <ShortName>SEC Schedule, Article 12-04, Condensed Financial Information of Registrant</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9952185 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.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>36</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure</Role>
      <ShortName>Cybersecurity Risk Management and Strategy Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - CHANGE IN ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CHANGEINACCOUNTINGPOLICIESTables</Role>
      <ShortName>CHANGE IN ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/CHANGEINACCOUNTINGPOLICIES</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/EarningsPerShare</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - ALLOWANCE FOR DOUBTFUL ACCOUNTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/ALLOWANCEFORDOUBTFULACCOUNTSTables</Role>
      <ShortName>ALLOWANCE FOR DOUBTFUL ACCOUNTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/ALLOWANCEFORDOUBTFULACCOUNTS</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUPPLEMENTALCASHFLOWINFORMATIONTables</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SUPPLEMENTALCASHFLOWINFORMATION</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - RESTRUCTURING AND OTHER EXPENSE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/RESTRUCTURINGANDOTHEREXPENSETables</Role>
      <ShortName>RESTRUCTURING AND OTHER EXPENSE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/RESTRUCTURINGANDOTHEREXPENSE</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/PROPERTYPLANTANDEQUIPMENTTables</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/PROPERTYPLANTANDEQUIPMENT</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/LEASESTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/LEASES</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - INTANGIBLE ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTANGIBLEASSETSTables</Role>
      <ShortName>INTANGIBLE ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/INTANGIBLEASSETS</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTTables</Role>
      <ShortName>DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/DEBT</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESSTables</Role>
      <ShortName>DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESS</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - FAIR VALUE MEASUREMENT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/FAIRVALUEMEASUREMENTTables</Role>
      <ShortName>FAIR VALUE MEASUREMENT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/FAIRVALUEMEASUREMENT</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - INCOME TAXES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESTables</Role>
      <ShortName>INCOME TAXES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/INCOMETAXES</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - SHARE-BASED COMPENSATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SHAREBASEDCOMPENSATIONTables</Role>
      <ShortName>SHARE-BASED COMPENSATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SHAREBASEDCOMPENSATION</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - AFFILIATE AND RELATED PARTY TRANSACTIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/AFFILIATEANDRELATEDPARTYTRANSACTIONSTables</Role>
      <ShortName>AFFILIATE AND RELATED PARTY TRANSACTIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/AFFILIATEANDRELATEDPARTYTRANSACTIONS</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/COMMITMENTSANDCONTINGENCIESTables</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/COMMITMENTSANDCONTINGENCIES</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SegmentReporting</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - SEC Schedule, Article 12-04, Condensed Financial Information of Registrant (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SECScheduleArticle1204CondensedFinancialInformationofRegistrantTables</Role>
      <ShortName>SEC Schedule, Article 12-04, Condensed Financial Information of Registrant (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SECScheduleArticle1204CondensedFinancialInformationofRegistrant</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - DESCRIPTION OF BUSINESS AND RELATED MATTERS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DESCRIPTIONOFBUSINESSANDRELATEDMATTERSDetails</Role>
      <ShortName>DESCRIPTION OF BUSINESS AND RELATED MATTERS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/DESCRIPTIONOFBUSINESSANDRELATEDMATTERS</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Contract Asset and Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESContractAssetandLiabilityDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Contract Asset and Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDisaggregationofRevenueDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Stock by Class (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofStockbyClassDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Stock by Class (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - CHANGE IN ACCOUNTING POLICIES - Balance Sheet (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/CHANGEINACCOUNTINGPOLICIESBalanceSheetDetails</Role>
      <ShortName>CHANGE IN ACCOUNTING POLICIES - Balance Sheet (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/EarningsPerShareDetails</Role>
      <ShortName>Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/EarningsPerShareTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - ALLOWANCE FOR DOUBTFUL ACCOUNTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/ALLOWANCEFORDOUBTFULACCOUNTSDetails</Role>
      <ShortName>ALLOWANCE FOR DOUBTFUL ACCOUNTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/ALLOWANCEFORDOUBTFULACCOUNTSTables</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUPPLEMENTALCASHFLOWINFORMATIONDetails</Role>
      <ShortName>SUPPLEMENTAL CASH FLOW INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SUPPLEMENTALCASHFLOWINFORMATIONTables</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - RESTRUCTURING AND OTHER EXPENSE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/RESTRUCTURINGANDOTHEREXPENSEDetails</Role>
      <ShortName>RESTRUCTURING AND OTHER EXPENSE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/RESTRUCTURINGANDOTHEREXPENSETables</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/PROPERTYPLANTANDEQUIPMENTNarrativeDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/PROPERTYPLANTANDEQUIPMENTSummaryDetails</Role>
      <ShortName>PROPERTY, PLANT AND EQUIPMENT - Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - LEASES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/LEASESDetails</Role>
      <ShortName>LEASES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/LEASESTables</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - LEASES - Future Minimum Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/LEASESFutureMinimumLeasePaymentsDetails</Role>
      <ShortName>LEASES - Future Minimum Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - INTANGIBLE ASSETS - Summary of Acquired Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTANGIBLEASSETSSummaryofAcquiredIntangibleAssetsDetails</Role>
      <ShortName>INTANGIBLE ASSETS - Summary of Acquired Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - INTANGIBLE ASSETS - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTANGIBLEASSETSNarrativeDetails</Role>
      <ShortName>INTANGIBLE ASSETS - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - INTANGIBLE ASSETS - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTANGIBLEASSETSScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseDetails</Role>
      <ShortName>INTANGIBLE ASSETS - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - INTANGIBLE ASSETS - Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTANGIBLEASSETSGoodwillDetails</Role>
      <ShortName>INTANGIBLE ASSETS - Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - DEBT - Outstanding Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTOutstandingDebtDetails</Role>
      <ShortName>DEBT - Outstanding Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - DEBT - CSC Holdings Credit Facilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTCSCHoldingsCreditFacilitiesDetails</Role>
      <ShortName>DEBT - CSC Holdings Credit Facilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>9955554 - Disclosure - DEBT - Senior Guaranteed Notes and Senior Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.optimum.com/role/DEBTSeniorGuaranteedNotesandSeniorNotesDetails</Role>
      <ShortName>DEBT - Senior Guaranteed Notes and Senior Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>9955555 - Disclosure - DEBT - ABS Loan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTABSLoanDetails</Role>
      <ShortName>DEBT - ABS Loan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>9955556 - Disclosure - DEBT - Unsub Loan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTUnsubLoanDetails</Role>
      <ShortName>DEBT - Unsub Loan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>9955557 - Disclosure - DEBT - Lightpath (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTLightpathDetails</Role>
      <ShortName>DEBT - Lightpath (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>9955558 - Disclosure - DEBT - Schedule of Gain (Loss) on Debt Extinguishment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTScheduleofGainLossonDebtExtinguishmentDetails</Role>
      <ShortName>DEBT - Schedule of Gain (Loss) on Debt Extinguishment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>9955559 - Disclosure - DEBT - Supply Chain Financing Arrangement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTSupplyChainFinancingArrangementDetails</Role>
      <ShortName>DEBT - Supply Chain Financing Arrangement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>9955560 - Disclosure - DEBT - Summary of Debt Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DEBTSummaryofDebtMaturitiesDetails</Role>
      <ShortName>DEBT - Summary of Debt Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>9955561 - Disclosure - DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESSNarrativeDetails</Role>
      <ShortName>DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESSTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>9955562 - Disclosure - DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Schedule of Interest Rate Derivatives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESSScheduleofInterestRateDerivativesDetails</Role>
      <ShortName>DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Schedule of Interest Rate Derivatives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>9955563 - Disclosure - DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Location of Assets and Liabilities Within the Consolidated Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESSLocationofAssetsandLiabilitiesWithintheConsolidatedBalanceSheetsDetails</Role>
      <ShortName>DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Location of Assets and Liabilities Within the Consolidated Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>9955564 - Disclosure - DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Settlements of Collateralized Indebtedness (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/DERIVATIVECONTRACTSANDCOLLATERALIZEDINDEBTEDNESSSettlementsofCollateralizedIndebtednessDetails</Role>
      <ShortName>DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Settlements of Collateralized Indebtedness (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>9955565 - Disclosure - FAIR VALUE MEASUREMENT - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/FAIRVALUEMEASUREMENTAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails</Role>
      <ShortName>FAIR VALUE MEASUREMENT - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>9955567 - Disclosure - FAIR VALUE MEASUREMENT - Fair Value of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/FAIRVALUEMEASUREMENTFairValueofFinancialInstrumentsDetails</Role>
      <ShortName>FAIR VALUE MEASUREMENT - Fair Value of Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>9955568 - Disclosure - INCOME TAXES - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESNarrativeDetails</Role>
      <ShortName>INCOME TAXES - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>9955569 - Disclosure - INCOME TAXES - Pre tax income loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESPretaxincomelossDetails</Role>
      <ShortName>INCOME TAXES - Pre tax income loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>9955570 - Disclosure - INCOME TAXES - Income Tax Expense (Benefit) Continuing Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESIncomeTaxExpenseBenefitContinuingOperationsDetails</Role>
      <ShortName>INCOME TAXES - Income Tax Expense (Benefit) Continuing Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>9955571 - Disclosure - INCOME TAXES - Effective Tax Rate Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESEffectiveTaxRateReconciliationDetails</Role>
      <ShortName>INCOME TAXES - Effective Tax Rate Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>9955572 - Disclosure - INCOME TAXES - Deferred Tax Assets (Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESDeferredTaxAssetsLiabilitiesDetails</Role>
      <ShortName>INCOME TAXES - Deferred Tax Assets (Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>9955573 - Disclosure - INCOME TAXES - Income Taxes Paid (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESIncomeTaxesPaidDetails</Role>
      <ShortName>INCOME TAXES - Income Taxes Paid (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>9955574 - Disclosure - INCOME TAXES - Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INCOMETAXESUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>INCOME TAXES - Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>9955575 - Disclosure - SHARE-BASED COMPENSATION - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SHAREBASEDCOMPENSATIONNarrativeDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>9955577 - Disclosure - SHARE-BASED COMPENSATION - Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SHAREBASEDCOMPENSATIONStockOptionActivityDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION - Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>9955578 - Disclosure - SHARE-BASED COMPENSATION - Fair Value Assumptions For Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SHAREBASEDCOMPENSATIONFairValueAssumptionsForStockOptionsDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION - Fair Value Assumptions For Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>9955579 - Disclosure - SHARE-BASED COMPENSATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SHAREBASEDCOMPENSATIONDetails</Role>
      <ShortName>SHARE-BASED COMPENSATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SHAREBASEDCOMPENSATIONTables</ParentRole>
      <Position>101</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>9955580 - Disclosure - Performance based awards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/PerformancebasedawardsDetails</Role>
      <ShortName>Performance based awards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>9955581 - Disclosure - Restricted stock units (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/RestrictedstockunitsDetails</Role>
      <ShortName>Restricted stock units (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>9955582 - Disclosure - AFFILIATE AND RELATED PARTY TRANSACTIONS - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/AFFILIATEANDRELATEDPARTYTRANSACTIONSNarrativeDetails</Role>
      <ShortName>AFFILIATE AND RELATED PARTY TRANSACTIONS - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>9955583 - Disclosure - AFFILIATE AND RELATED PARTY TRANSACTIONS - Revenue and Related Charges (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/AFFILIATEANDRELATEDPARTYTRANSACTIONSRevenueandRelatedChargesDetails</Role>
      <ShortName>AFFILIATE AND RELATED PARTY TRANSACTIONS - Revenue and Related Charges (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>9955584 - Disclosure - AFFILIATE AND RELATED PARTY TRANSACTIONS - Amounts Due From and Due to Related Parties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/AFFILIATEANDRELATEDPARTYTRANSACTIONSAmountsDueFromandDuetoRelatedPartiesDetails</Role>
      <ShortName>AFFILIATE AND RELATED PARTY TRANSACTIONS - Amounts Due From and Due to Related Parties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>9955585 - Disclosure - COMMITMENTS AND CONTINGENCIES - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/COMMITMENTSANDCONTINGENCIESNarrativeDetails</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>9955586 - Disclosure - COMMITMENTS AND CONTINGENCIES - Future Cash Payments and Commitments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/COMMITMENTSANDCONTINGENCIESFutureCashPaymentsandCommitmentsDetails</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES - Future Cash Payments and Commitments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>9955587 - Disclosure - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SegmentReportingDetails</Role>
      <ShortName>Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.optimum.com/role/SegmentReportingTables</ParentRole>
      <Position>109</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>9955589 - Disclosure - Restricted Group Condensed Balance Sheet (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/RestrictedGroupCondensedBalanceSheetDetails</Role>
      <ShortName>Restricted Group Condensed Balance Sheet (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>9955590 - Disclosure - Restricted Group Condensed Income Statement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/RestrictedGroupCondensedIncomeStatementDetails</Role>
      <ShortName>Restricted Group Condensed Income Statement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>9955591 - Disclosure - SUBSEQUENT EVENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/SUBSEQUENTEVENTSDetails</Role>
      <ShortName>SUBSEQUENT EVENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="optu-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>9955600 - Disclosure - INTERIM FINANCIAL INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.optimum.com/role/INTERIMFINANCIALINFORMATIONDetails</Role>
      <ShortName>INTERIM FINANCIAL INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-K" isDefinitelyFs="true" isUsgaap="true" original="optu-20251231.htm">optu-20251231.htm</File>
    <File>optu-20251231.xsd</File>
    <File>optu-20251231_cal.xml</File>
    <File>optu-20251231_def.xml</File>
    <File>optu-20251231_lab.xml</File>
    <File>optu-20251231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>optu-20251231_g1.jpg</File>
    <File>optu-20251231_g2.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="4">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="2016">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="6">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="38">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="10">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
