<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>4096</ContextCount>
  <ElementCount>375</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>327</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>12</UnitCount>
  <MyReports>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0000003 - Statement - CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIES</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0000004 - Statement - CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIESParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0000005 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0000006 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINNETASSETS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0000007 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>0000008 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTS</Role>
      <ShortName>CONSOLIDATED SCHEDULE OF INVESTMENTS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>0000009 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS (Foreign currency forward contracts)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSForeigncurrencyforwardcontracts</Role>
      <ShortName>CONSOLIDATED SCHEDULE OF INVESTMENTS (Foreign currency forward contracts)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>0000010 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSParenthetical</Role>
      <ShortName>CONSOLIDATED SCHEDULE OF INVESTMENTS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>0000011 - Disclosure - Organization and Principal Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/OrganizationandPrincipalBusiness</Role>
      <ShortName>Organization and Principal Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>0000012 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>0000013 - Disclosure - Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Investments</Role>
      <ShortName>Investments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>0000014 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>0000015 - Disclosure - Transactions with Affiliate Companies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithAffiliateCompanies</Role>
      <ShortName>Transactions with Affiliate Companies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>0000016 - Disclosure - Transactions with Related Parties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithRelatedParties</Role>
      <ShortName>Transactions with Related Parties</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>0000017 - Disclosure - Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Borrowings</Role>
      <ShortName>Borrowings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>0000018 - Disclosure - Derivative Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/DerivativeInstruments</Role>
      <ShortName>Derivative Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>0000019 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>0000020 - Disclosure - Distributions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Distributions</Role>
      <ShortName>Distributions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>0000021 - Disclosure - Stock Issuances and Share Repurchase Program</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/StockIssuancesandShareRepurchaseProgram</Role>
      <ShortName>Stock Issuances and Share Repurchase Program</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>0000022 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>0000023 - Disclosure - Financial Highlights</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FinancialHighlights</Role>
      <ShortName>Financial Highlights</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>0000024 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>0000025 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.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>27</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.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>28</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/InvestmentsTables</Role>
      <ShortName>Investments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/Investments</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/FairValueMeasurements</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - Transactions with Affiliate Companies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithAffiliateCompaniesTables</Role>
      <ShortName>Transactions with Affiliate Companies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/TransactionswithAffiliateCompanies</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - Transactions with Related Parties (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithRelatedPartiesTables</Role>
      <ShortName>Transactions with Related Parties (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/TransactionswithRelatedParties</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - Borrowings (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsTables</Role>
      <ShortName>Borrowings (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/Borrowings</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - Derivative Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/DerivativeInstrumentsTables</Role>
      <ShortName>Derivative Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/DerivativeInstruments</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/IncomeTaxes</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - Distributions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/DistributionsTables</Role>
      <ShortName>Distributions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/Distributions</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - Stock Issuances and Share Repurchase Program (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/StockIssuancesandShareRepurchaseProgramTables</Role>
      <ShortName>Stock Issuances and Share Repurchase Program (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/StockIssuancesandShareRepurchaseProgram</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CommitmentsandContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/CommitmentsandContingencies</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - Financial Highlights (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FinancialHighlightsTables</Role>
      <ShortName>Financial Highlights (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/FinancialHighlights</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - Organization and Principal Business (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/OrganizationandPrincipalBusinessDetails</Role>
      <ShortName>Organization and Principal Business (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/OrganizationandPrincipalBusiness</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - Summary of Significant Accounting Policies - Revenue Recognition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPoliciesRevenueRecognitionDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Revenue Recognition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - Summary of Significant Accounting Policies - Schedule of Components of the Company's Investment Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPoliciesScheduleofComponentsoftheCompanysInvestmentIncomeDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Schedule of Components of the Company's Investment Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - Summary of Significant Accounting Policies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - Summary of Significant Accounting Policies - Schedule of Restricted Cash and Cash Equivalents (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SummaryofSignificantAccountingPoliciesScheduleofRestrictedCashandCashEquivalentsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Schedule of Restricted Cash and Cash Equivalents (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - Investments - Schedule of Composition of the Company's Investment Portfolio, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/InvestmentsScheduleofCompositionoftheCompanysInvestmentPortfolioatAmortizedCostandFairValuewithCorrespondingPercentageofTotalPortfolioInvestmentsDetails</Role>
      <ShortName>Investments - Schedule of Composition of the Company's Investment Portfolio, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - Investments - Schedule of Composition of the Company's Investment Portfolio by Geographic Region, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/InvestmentsScheduleofCompositionoftheCompanysInvestmentPortfoliobyGeographicRegionatAmortizedCostandFairValuewithCorrespondingPercentageofTotalPortfolioInvestmentsDetails</Role>
      <ShortName>Investments - Schedule of Composition of the Company's Investment Portfolio by Geographic Region, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - Investments - Schedule of Composition of the Company's Investment Portfolio by Industry, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/InvestmentsScheduleofCompositionoftheCompanysInvestmentPortfoliobyIndustryatAmortizedCostandFairValuewithCorrespondingPercentageofTotalPortfolioInvestmentsDetails</Role>
      <ShortName>Investments - Schedule of Composition of the Company's Investment Portfolio by Industry, at Amortized Cost and Fair Value (with Corresponding Percentage of Total Portfolio Investments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - Fair Value Measurements - Schedule of Fair Value Measurements of Investments and Foreign Currency Forward Contracts, by Major Class According to the Fair Value Hierarchy (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsScheduleofFairValueMeasurementsofInvestmentsandForeignCurrencyForwardContractsbyMajorClassAccordingtotheFairValueHierarchyDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Fair Value Measurements of Investments and Foreign Currency Forward Contracts, by Major Class According to the Fair Value Hierarchy (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - Fair Value Measurements - Contractual Interest Rates (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsContractualInterestRatesDetails</Role>
      <ShortName>Fair Value Measurements - Contractual Interest Rates (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - Fair Value Measurements - Schedule of Reconciliation of the Beginning and Ending Balances for Investments at Fair Value that use Level 3 Inputs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsScheduleofReconciliationoftheBeginningandEndingBalancesforInvestmentsatFairValuethatuseLevel3InputsDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Reconciliation of the Beginning and Ending Balances for Investments at Fair Value that use Level 3 Inputs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - Fair Value Measurements - Schedule of Valuation Techniques and Significant Unobservable Inputs used in Recurring Level 3 Fair Value Measurements of Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsScheduleofValuationTechniquesandSignificantUnobservableInputsusedinRecurringLevel3FairValueMeasurementsofAssetsandLiabilitiesDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Valuation Techniques and Significant Unobservable Inputs used in Recurring Level 3 Fair Value Measurements of Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - Fair Value Measurements - Schedule of Carrying Values and Fair Values of Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsScheduleofCarryingValuesandFairValuesofDebtDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Carrying Values and Fair Values of Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - Fair Value Measurements - Schedule of Fair value measurements of the Company???s debt obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FairValueMeasurementsScheduleofFairvaluemeasurementsoftheCompanysdebtobligationsDetails</Role>
      <ShortName>Fair Value Measurements - Schedule of Fair value measurements of the Company???s debt obligations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - Transactions with Affiliate Companies - Schedule of Fair Value Roll Forward (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithAffiliateCompaniesScheduleofFairValueRollForwardDetails</Role>
      <ShortName>Transactions with Affiliate Companies - Schedule of Fair Value Roll Forward (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - Transactions with Affiliate Companies - Schedule of Income Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithAffiliateCompaniesScheduleofIncomeInformationDetails</Role>
      <ShortName>Transactions with Affiliate Companies - Schedule of Income Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - Transactions with Related Parties - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithRelatedPartiesNarrativeDetails</Role>
      <ShortName>Transactions with Related Parties - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - Transactions with Related Parties - Schedule of Composition of the Company's Incentive Fees (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/TransactionswithRelatedPartiesScheduleofCompositionoftheCompanysIncentiveFeesDetails</Role>
      <ShortName>Transactions with Related Parties - Schedule of Composition of the Company's Incentive Fees (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - Borrowings - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsNarrativeDetails</Role>
      <ShortName>Borrowings - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - Borrowings - Schedule of Company's Outstanding Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsScheduleofCompanysOutstandingDebtDetails</Role>
      <ShortName>Borrowings - Schedule of Company's Outstanding Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - Borrowings - Revolving Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsRevolvingCreditFacilityDetails</Role>
      <ShortName>Borrowings - Revolving Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - Borrowings - SPV Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsSPVCreditFacilityDetails</Role>
      <ShortName>Borrowings - SPV Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - Borrowings - SPV II Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsSPVIICreditFacilityDetails</Role>
      <ShortName>Borrowings - SPV II Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - Borrowings - SPV III Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsSPVIIICreditFacilityDetails</Role>
      <ShortName>Borrowings - SPV III Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - Borrowings - SPV IV Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsSPVIVCreditFacilityDetails</Role>
      <ShortName>Borrowings - SPV IV Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - Borrowings - SPV V Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsSPVVCreditFacilityDetails</Role>
      <ShortName>Borrowings - SPV V Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - Borrowings - 2022 Asset-Backed Securitization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Borrowings2022AssetBackedSecuritizationDetails</Role>
      <ShortName>Borrowings - 2022 Asset-Backed Securitization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - Borrowings - 2023 Asset-Backed Securitization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Borrowings2023AssetBackedSecuritizationDetails</Role>
      <ShortName>Borrowings - 2023 Asset-Backed Securitization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - Borrowings - 2025 Asset-Backed Securitization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/Borrowings2025AssetBackedSecuritizationDetails</Role>
      <ShortName>Borrowings - 2025 Asset-Backed Securitization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - Borrowings - July 2028 Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsJuly2028NotesDetails</Role>
      <ShortName>Borrowings - July 2028 Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>9955554 - Disclosure - Borrowings - November 2028 Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsNovember2028NotesDetails</Role>
      <ShortName>Borrowings - November 2028 Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>9955555 - Disclosure - Borrowings - December 2028 Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsDecember2028NotesDetails</Role>
      <ShortName>Borrowings - December 2028 Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>9955556 - Disclosure - Borrowings - July 2029 Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsJuly2029NotesDetails</Role>
      <ShortName>Borrowings - July 2029 Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>9955557 - Disclosure - Borrowings - September 2029 Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsSeptember2029NotesDetails</Role>
      <ShortName>Borrowings - September 2029 Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>9955558 - Disclosure - Borrowings - July 2030 Notes (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsJuly2030NotesDetails</Role>
      <ShortName>Borrowings - July 2030 Notes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>9955559 - Disclosure - Borrowings - Schedule of Components of the Company's Interest Expense and Other Debt Financing Expenses, Average Debt Outstanding Balances and Average Stated Interest Rates (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/BorrowingsScheduleofComponentsoftheCompanysInterestExpenseandOtherDebtFinancingExpensesAverageDebtOutstandingBalancesandAverageStatedInterestRatesDetails</Role>
      <ShortName>Borrowings - Schedule of Components of the Company's Interest Expense and Other Debt Financing Expenses, Average Debt Outstanding Balances and Average Stated Interest Rates (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>9955560 - Disclosure - Derivative Instruments - Schedule of Information Related to Foreign Currency Forward Contracts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/DerivativeInstrumentsScheduleofInformationRelatedtoForeignCurrencyForwardContractsDetails</Role>
      <ShortName>Derivative Instruments - Schedule of Information Related to Foreign Currency Forward Contracts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>9955561 - Disclosure - Derivative Instruments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/DerivativeInstrumentsNarrativeDetails</Role>
      <ShortName>Derivative Instruments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>9955562 - Disclosure - Income Taxes - Schedule of Permanent Differences Reclassified for Tax Purposes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/IncomeTaxesScheduleofPermanentDifferencesReclassifiedforTaxPurposesDetails</Role>
      <ShortName>Income Taxes - Schedule of Permanent Differences Reclassified for Tax Purposes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>9955563 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>9955564 - Disclosure - Income Taxes - Schedule of Net Increase in Net Assets Resulting from Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/IncomeTaxesScheduleofNetIncreaseinNetAssetsResultingfromOperationsDetails</Role>
      <ShortName>Income Taxes - Schedule of Net Increase in Net Assets Resulting from Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>9955565 - Disclosure - Income Taxes - Schedule of Distributions Paid (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/IncomeTaxesScheduleofDistributionsPaidDetails</Role>
      <ShortName>Income Taxes - Schedule of Distributions Paid (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>9955566 - Disclosure - Distributions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/DistributionsDetails</Role>
      <ShortName>Distributions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/DistributionsTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>9955567 - Disclosure - Stock Issuances and Share Repurchase Program - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/StockIssuancesandShareRepurchaseProgramNarrativeDetails</Role>
      <ShortName>Stock Issuances and Share Repurchase Program - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>9955568 - Disclosure - Stock Issuances and Share Repurchase Program - Schedule of Stock Issuances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/StockIssuancesandShareRepurchaseProgramScheduleofStockIssuancesDetails</Role>
      <ShortName>Stock Issuances and Share Repurchase Program - Schedule of Stock Issuances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>9955569 - Disclosure - Stock Issuances and Share Repurchase Program - Schedule of Share Repurchase Program (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/StockIssuancesandShareRepurchaseProgramScheduleofShareRepurchaseProgramDetails</Role>
      <ShortName>Stock Issuances and Share Repurchase Program - Schedule of Share Repurchase Program (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>9955570 - Disclosure - Commitments and Contingencies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CommitmentsandContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>9955571 - Disclosure - Commitments and Contingencies - Schedule Of Committed Capital (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/CommitmentsandContingenciesScheduleOfCommittedCapitalDetails</Role>
      <ShortName>Commitments and Contingencies - Schedule Of Committed Capital (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>9955572 - Disclosure - Financial Highlights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/FinancialHighlightsDetails</Role>
      <ShortName>Financial Highlights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/FinancialHighlightsTables</ParentRole>
      <Position>90</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>9955573 - Disclosure - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SegmentReportingDetails</Role>
      <ShortName>Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/SegmentReporting</ParentRole>
      <Position>91</Position>
    </Report>
    <Report instance="mcip-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>9955574 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.monroebdc.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.monroebdc.com/role/SubsequentEvents</ParentRole>
      <Position>92</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="mcip-20251231.htm">mcip-20251231.htm</File>
    <File>mcip-20251231.xsd</File>
    <File>mcip-20251231_cal.xml</File>
    <File>mcip-20251231_def.xml</File>
    <File>mcip-20251231_lab.xml</File>
    <File>mcip-20251231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>mcip-20251231_g1.jpg</File>
    <File>mcip-20251231_g2.jpg</File>
    <File>mcip-20251231_g3.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="1">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="14243">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="44">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="6">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
