<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>460</ContextCount>
  <ElementCount>558</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>104</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - COVER</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/COVER</Role>
      <ShortName>COVER</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952151 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952152 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952153 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952154 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952155 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952156 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (DEFICIT)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINEQUITYDEFICIT</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (DEFICIT)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952157 - Disclosure - Description of Business, Basis of Preparation and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPolicies</Role>
      <ShortName>Description of Business, Basis of Preparation and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952158 - Disclosure - Revenue from Contracts with Customers</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomers</Role>
      <ShortName>Revenue from Contracts with Customers</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - Operating and Administrative Expenses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/OperatingandAdministrativeExpenses</Role>
      <ShortName>Operating and Administrative Expenses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/Acquisitions</Role>
      <ShortName>Acquisitions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - Inventories, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/InventoriesNet</Role>
      <ShortName>Inventories, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - Property, Plant and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PropertyPlantandEquipmentNet</Role>
      <ShortName>Property, Plant and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - Goodwill and Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssets</Role>
      <ShortName>Goodwill and Other Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - Prepaid and Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PrepaidandOtherCurrentAssets</Role>
      <ShortName>Prepaid and Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/OtherCurrentLiabilities</Role>
      <ShortName>Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - Taxes on Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLoss</Role>
      <ShortName>Taxes on Income (Loss)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - Employee Benefits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EmployeeBenefits</Role>
      <ShortName>Employee Benefits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9952170 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9952171 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9952172 - Disclosure - Stockholder's Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockholdersEquityDeficit</Role>
      <ShortName>Stockholder's Equity (Deficit)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9952173 - Disclosure - Accumulated Other Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/AccumulatedOtherComprehensiveIncomeLoss</Role>
      <ShortName>Accumulated Other Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9952174 - Disclosure - Earnings (Loss) per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EarningsLossperShare</Role>
      <ShortName>Earnings (Loss) per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9952175 - Disclosure - Management Fee</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ManagementFee</Role>
      <ShortName>Management Fee</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9952176 - Disclosure - Commitment and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CommitmentandContingencies</Role>
      <ShortName>Commitment and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9952177 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9952178 - Disclosure - Schedule I - PARENT COMPANY INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ScheduleIPARENTCOMPANYINFORMATION</Role>
      <ShortName>Schedule I - PARENT COMPANY INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9952179 - Disclosure - Schedule II - VALUATION AND QUALIFYING ACCOUNTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ScheduleIIVALUATIONANDQUALIFYINGACCOUNTS</Role>
      <ShortName>Schedule II - VALUATION AND QUALIFYING ACCOUNTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.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>32</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.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>33</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.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>34</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - Description of Business, Basis of Preparation and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Description of Business, Basis of Preparation and Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPolicies</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - Description of Business, Basis of Preparation and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>Description of Business, Basis of Preparation and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPolicies</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - Revenue from Contracts with Customers (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersTables</Role>
      <ShortName>Revenue from Contracts with Customers (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/RevenuefromContractswithCustomers</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Operating and Administrative Expenses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/OperatingandAdministrativeExpensesTables</Role>
      <ShortName>Operating and Administrative Expenses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/OperatingandAdministrativeExpenses</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - Property, Plant and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PropertyPlantandEquipmentNetTables</Role>
      <ShortName>Property, Plant and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/PropertyPlantandEquipmentNet</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - Goodwill and Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Other Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssets</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - Prepaid and Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PrepaidandOtherCurrentAssetsTables</Role>
      <ShortName>Prepaid and Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/PrepaidandOtherCurrentAssets</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/OtherCurrentLiabilitiesTables</Role>
      <ShortName>Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/OtherCurrentLiabilities</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/Debt</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/SegmentReporting</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - Taxes on Income (Loss) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossTables</Role>
      <ShortName>Taxes on Income (Loss) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLoss</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/StockBasedCompensation</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/Leases</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/AccumulatedOtherComprehensiveIncomeLossTables</Role>
      <ShortName>Accumulated Other Comprehensive Income (Loss) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/AccumulatedOtherComprehensiveIncomeLoss</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - Earnings (Loss) per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EarningsLossperShareTables</Role>
      <ShortName>Earnings (Loss) per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/EarningsLossperShare</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - Description of Business, Basis of Preparation and Summary of Significant Accounting Policies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Description of Business, Basis of Preparation and Summary of Significant Accounting Policies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPoliciesTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - Description of Business, Basis of Preparation and Summary of Significant Accounting Policies - Carrying Amounts and Estimated Fair Market Values of Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DescriptionofBusinessBasisofPreparationandSummaryofSignificantAccountingPoliciesCarryingAmountsandEstimatedFairMarketValuesofDebtDetails</Role>
      <ShortName>Description of Business, Basis of Preparation and Summary of Significant Accounting Policies - Carrying Amounts and Estimated Fair Market Values of Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - Revenue from Contracts with Customers - Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersDisaggregationofRevenueDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - Revenue from Contracts with Customers - Deferred Commission Costs and Deferred Royalties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersDeferredCommissionCostsandDeferredRoyaltiesDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Deferred Commission Costs and Deferred Royalties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - Revenue from Contracts with Customers - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersNarrativeDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - Revenue from Contracts with Customers - Contract Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Contract Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - Revenue from Contracts with Customers - Contract Liabilities by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersContractLiabilitiesbySegmentDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Contract Liabilities by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - Revenue from Contracts with Customers - Estimated Revenue Expected to be Recognized (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/RevenuefromContractswithCustomersEstimatedRevenueExpectedtobeRecognizedDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Estimated Revenue Expected to be Recognized (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - Operating and Administrative Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/OperatingandAdministrativeExpensesDetails</Role>
      <ShortName>Operating and Administrative Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/OperatingandAdministrativeExpensesTables</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - Acquisitions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/AcquisitionsDetails</Role>
      <ShortName>Acquisitions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/Acquisitions</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - Inventories, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/InventoriesNetDetails</Role>
      <ShortName>Inventories, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/InventoriesNet</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - Property, Plant and Equipment, Net - Schedule of Property, Plant and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PropertyPlantandEquipmentNetScheduleofPropertyPlantandEquipmentNetDetails</Role>
      <ShortName>Property, Plant and Equipment, Net - Schedule of Property, Plant and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - Property, Plant and Equipment, Net - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PropertyPlantandEquipmentNetNarrativeDetails</Role>
      <ShortName>Property, Plant and Equipment, Net - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - Goodwill and Other Intangible Assets - Changes in Carrying Value of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssetsChangesinCarryingValueofGoodwillDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Changes in Carrying Value of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - Goodwill and Other Intangible Assets - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssetsSummaryofOtherIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - Goodwill and Other Intangible Assets - Expected Aggregate Annual Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/GoodwillandOtherIntangibleAssetsExpectedAggregateAnnualAmortizationExpenseDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Expected Aggregate Annual Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - Prepaid and Other Current Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/PrepaidandOtherCurrentAssetsDetails</Role>
      <ShortName>Prepaid and Other Current Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/PrepaidandOtherCurrentAssetsTables</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/OtherCurrentLiabilitiesDetails</Role>
      <ShortName>Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/OtherCurrentLiabilitiesTables</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - Debt - Summary of Long-Term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtSummaryofLongTermDebtDetails</Role>
      <ShortName>Debt - Summary of Long-Term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - Debt - A&amp;E Cash Flow Credit Facilities, Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtAECashFlowCreditFacilitiesNarrativeDetails</Role>
      <ShortName>Debt - A&amp;E Cash Flow Credit Facilities, Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - Debt - A&amp;E ABL Revolving Credit Facilities, Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtAEABLRevolvingCreditFacilitiesNarrativeDetails</Role>
      <ShortName>Debt - A&amp;E ABL Revolving Credit Facilities, Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - Debt - Secured and Unsecured Notes, Narrative (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.mheducation.com/role/DebtSecuredandUnsecuredNotesNarrativeDetails</Role>
      <ShortName>Debt - Secured and Unsecured Notes, Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - Debt - Unamortized Debt Discount and Deferred Financing Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtUnamortizedDebtDiscountandDeferredFinancingCostsDetails</Role>
      <ShortName>Debt - Unamortized Debt Discount and Deferred Financing Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - Debt - Debt Issuance Costs, Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtDebtIssuanceCostsNarrativeDetails</Role>
      <ShortName>Debt - Debt Issuance Costs, Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - Debt - Principal Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/DebtPrincipalPaymentsDetails</Role>
      <ShortName>Debt - Principal Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - Segment Reporting - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SegmentReportingNarrativeDetails</Role>
      <ShortName>Segment Reporting - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - Segment Reporting - Adjusted EBITDA by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SegmentReportingAdjustedEBITDAbySegmentDetails</Role>
      <ShortName>Segment Reporting - Adjusted EBITDA by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>9955554 - Disclosure - Segment Reporting - Reconciliation of Adjusted EBITDA to Net Income (Loss) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SegmentReportingReconciliationofAdjustedEBITDAtoNetIncomeLossDetails</Role>
      <ShortName>Segment Reporting - Reconciliation of Adjusted EBITDA to Net Income (Loss) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>9955555 - Disclosure - Segment Reporting - Revenue and Long-lived Assets by Geographic Region (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SegmentReportingRevenueandLonglivedAssetsbyGeographicRegionDetails</Role>
      <ShortName>Segment Reporting - Revenue and Long-lived Assets by Geographic Region (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>9955556 - Disclosure - Taxes on Income (Loss) - Income (Loss) Before Taxes on Income from Domestic and Foreign Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossIncomeLossBeforeTaxesonIncomefromDomesticandForeignOperationsDetails</Role>
      <ShortName>Taxes on Income (Loss) - Income (Loss) Before Taxes on Income from Domestic and Foreign Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>80</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>9955557 - Disclosure - Taxes on Income (Loss) - Provision (Benefit) for Taxes on Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossProvisionBenefitforTaxesonIncomeDetails</Role>
      <ShortName>Taxes on Income (Loss) - Provision (Benefit) for Taxes on Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>81</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>9955558 - Disclosure - Taxes on Income (Loss) - Effective Income Tax Rate Reconciliation (After ASU Adoption) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossEffectiveIncomeTaxRateReconciliationAfterASUAdoptionDetails</Role>
      <ShortName>Taxes on Income (Loss) - Effective Income Tax Rate Reconciliation (After ASU Adoption) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>9955559 - Disclosure - Taxes on Income (Loss) - Effective Income Tax Rate Reconciliation (Before ASU Adoption) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossEffectiveIncomeTaxRateReconciliationBeforeASUAdoptionDetails</Role>
      <ShortName>Taxes on Income (Loss) - Effective Income Tax Rate Reconciliation (Before ASU Adoption) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>9955560 - Disclosure - Taxes on Income (Loss) - Temporary Differences (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossTemporaryDifferencesDetails</Role>
      <ShortName>Taxes on Income (Loss) - Temporary Differences (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>9955561 - Disclosure - Taxes on Income (Loss) - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossNarrativeDetails</Role>
      <ShortName>Taxes on Income (Loss) - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>9955562 - Disclosure - Taxes on Income (Loss) - Cash Paid For Income Taxes, Net of Refunds (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossCashPaidForIncomeTaxesNetofRefundsDetails</Role>
      <ShortName>Taxes on Income (Loss) - Cash Paid For Income Taxes, Net of Refunds (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>86</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>9955563 - Disclosure - Taxes on Income (Loss) - Reconciliation of Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/TaxesonIncomeLossReconciliationofUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>Taxes on Income (Loss) - Reconciliation of Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/TaxesonIncomeLossTables</ParentRole>
      <Position>87</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>9955564 - Disclosure - Employee Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EmployeeBenefitsDetails</Role>
      <ShortName>Employee Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/EmployeeBenefits</ParentRole>
      <Position>88</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>9955565 - Disclosure - Stock-Based Compensation - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>9955566 - Disclosure - Stock-Based Compensation - Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationOptionActivityDetails</Role>
      <ShortName>Stock-Based Compensation - Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>9955567 - Disclosure - Stock-Based Compensation - Valuation Assumptions for Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationValuationAssumptionsforStockOptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Valuation Assumptions for Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>9955568 - Disclosure - Stock-Based Compensation - RSU and PSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationRSUandPSUActivityDetails</Role>
      <ShortName>Stock-Based Compensation - RSU and PSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>9955569 - Disclosure - Stock-Based Compensation - Valuation Assumptions for PSU's (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationValuationAssumptionsforPSUsDetails</Role>
      <ShortName>Stock-Based Compensation - Valuation Assumptions for PSU's (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>9955570 - Disclosure - Stock-Based Compensation - Stock Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockBasedCompensationStockBasedCompensationExpenseDetails</Role>
      <ShortName>Stock-Based Compensation - Stock Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>9955571 - Disclosure - Leases - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/LeasesNarrativeDetails</Role>
      <ShortName>Leases - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>9955572 - Disclosure - Leases - Balance Sheet Classification of Lease Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/LeasesBalanceSheetClassificationofLeaseAssetsandLiabilitiesDetails</Role>
      <ShortName>Leases - Balance Sheet Classification of Lease Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>9955573 - Disclosure - Leases - Lease Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/LeasesLeaseCostsDetails</Role>
      <ShortName>Leases - Lease Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>9955574 - Disclosure - Leases - Supplemental Cash Flow Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/LeasesSupplementalCashFlowInformationDetails</Role>
      <ShortName>Leases - Supplemental Cash Flow Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>9955575 - Disclosure - Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/LeasesScheduleofMaturitiesofOperatingandFinanceLeaseLiabilitiesDetails</Role>
      <ShortName>Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>9955576 - Disclosure - Stockholder's Equity (Deficit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/StockholdersEquityDeficitDetails</Role>
      <ShortName>Stockholder's Equity (Deficit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/StockholdersEquityDeficit</ParentRole>
      <Position>100</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>9955577 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/AccumulatedOtherComprehensiveIncomeLossDetails</Role>
      <ShortName>Accumulated Other Comprehensive Income (Loss) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/AccumulatedOtherComprehensiveIncomeLossTables</ParentRole>
      <Position>101</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>9955578 - Disclosure - Earnings (Loss) per Share - Computation of Basic and Diluted Earnings (Loss) per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EarningsLossperShareComputationofBasicandDilutedEarningsLossperShareDetails</Role>
      <ShortName>Earnings (Loss) per Share - Computation of Basic and Diluted Earnings (Loss) per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/EarningsLossperShareTables</ParentRole>
      <Position>102</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>9955579 - Disclosure - Earnings (Loss) per Share - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EarningsLossperShareNarrativeDetails</Role>
      <ShortName>Earnings (Loss) per Share - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/EarningsLossperShareTables</ParentRole>
      <Position>103</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>9955580 - Disclosure - Earnings (Loss) per Share - Common Stock Equivalents Excluded from Computation of Diluted Earnings (Loss) per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/EarningsLossperShareCommonStockEquivalentsExcludedfromComputationofDilutedEarningsLossperShareDetails</Role>
      <ShortName>Earnings (Loss) per Share - Common Stock Equivalents Excluded from Computation of Diluted Earnings (Loss) per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/EarningsLossperShareTables</ParentRole>
      <Position>104</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>9955581 - Disclosure - Management Fee (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ManagementFeeDetails</Role>
      <ShortName>Management Fee (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/ManagementFee</ParentRole>
      <Position>105</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>9955582 - Disclosure - Commitment and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/CommitmentandContingenciesDetails</Role>
      <ShortName>Commitment and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/CommitmentandContingencies</ParentRole>
      <Position>106</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>9955583 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/SubsequentEvents</ParentRole>
      <Position>107</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>9955584 - Disclosure - Schedule I - PARENT COMPANY INFORMATION - Condensed Consolidated Income Statement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ScheduleIPARENTCOMPANYINFORMATIONCondensedConsolidatedIncomeStatementDetails</Role>
      <ShortName>Schedule I - PARENT COMPANY INFORMATION - Condensed Consolidated Income Statement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>9955585 - Disclosure - Schedule I - PARENT COMPANY INFORMATION - Condensed Consolidated Balance Sheet (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ScheduleIPARENTCOMPANYINFORMATIONCondensedConsolidatedBalanceSheetDetails</Role>
      <ShortName>Schedule I - PARENT COMPANY INFORMATION - Condensed Consolidated Balance Sheet (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>9955586 - Disclosure - Schedule I - PARENT COMPANY INFORMATION - Condensed Consolidated Cash Flow (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ScheduleIPARENTCOMPANYINFORMATIONCondensedConsolidatedCashFlowDetails</Role>
      <ShortName>Schedule I - PARENT COMPANY INFORMATION - Condensed Consolidated Cash Flow (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="mh-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>9955587 - Disclosure - Schedule II - VALUATION AND QUALIFYING ACCOUNTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.mheducation.com/role/ScheduleIIVALUATIONANDQUALIFYINGACCOUNTSDetails</Role>
      <ShortName>Schedule II - VALUATION AND QUALIFYING ACCOUNTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.mheducation.com/role/ScheduleIIVALUATIONANDQUALIFYINGACCOUNTS</ParentRole>
      <Position>111</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="mh-20260331.htm">mh-20260331.htm</File>
    <File>mh-20260331.xsd</File>
    <File>mh-20260331_cal.xml</File>
    <File>mh-20260331_def.xml</File>
    <File>mh-20260331_lab.xml</File>
    <File>mh-20260331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>mh-20260331_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="2">http://fasb.org/srt/2026</BaseTaxonomy>
    <BaseTaxonomy items="1521">http://fasb.org/us-gaap/2026</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/cyd/2026</BaseTaxonomy>
    <BaseTaxonomy items="37">http://xbrl.sec.gov/dei/2026</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2026</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
