3.25.0.1 html 3046 470 1 true 236 0 false 10 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedStatementsOfAssetsAndLiabilities CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES Statements 2 false false R3.htm 100030 - Statement - CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES (Parenthetical) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedStatementsOfAssetsAndLiabilitiesParenthetical CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES (Parenthetical) Statements 3 false false R4.htm 100040 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedStatementsOfOperations CONSOLIDATED STATEMENTS OF OPERATIONS Statements 4 false false R5.htm 100050 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedStatementsOfChangesInNetAssets CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS Statements 5 false false R6.htm 100060 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 6 false false R7.htm 100070 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestments2 CONSOLIDATED SCHEDULE OF INVESTMENTS Statements 7 false false R8.htm 100080 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS (Parenthetical) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsParenthetical CONSOLIDATED SCHEDULE OF INVESTMENTS (Parenthetical) Statements 8 false false R9.htm 100090 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Fair Value along with Transactions in Affiliated Investments Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsFairValueAlongWithTransactionsInAffiliatedInvestments CONSOLIDATED SCHEDULE OF INVESTMENTS - Fair Value along with Transactions in Affiliated Investments Statements 9 false false R10.htm 100100 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Fair Value along with Transactions in Controlled Investments Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsFairValueAlongWithTransactionsInControlledInvestments CONSOLIDATED SCHEDULE OF INVESTMENTS - Fair Value along with Transactions in Controlled Investments Statements 10 false false R11.htm 100110 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Commitments to Funds Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsCommitmentsToFunds CONSOLIDATED SCHEDULE OF INVESTMENTS - Commitments to Funds Statements 11 false false R12.htm 100120 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Commitments to Funds (Parenthetical) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsCommitmentsToFundsParenthetical CONSOLIDATED SCHEDULE OF INVESTMENTS - Commitments to Funds (Parenthetical) Statements 12 false false R13.htm 100130 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Acquisition Dates of Restricted Securities Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsAcquisitionDatesOfRestrictedSecurities CONSOLIDATED SCHEDULE OF INVESTMENTS - Acquisition Dates of Restricted Securities Statements 13 false false R14.htm 100140 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Composition of Portfolio at Cost by Control Designation, Investment Type and Industry Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsCompositionOfPortfolioAtCostByControlDesignationInvestmentTypeAndIndustry CONSOLIDATED SCHEDULE OF INVESTMENTS - Composition of Portfolio at Cost by Control Designation, Investment Type and Industry Statements 14 false false R15.htm 100150 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Composition of Portfolio at Fair Value by Control Designation, Investment Type and Industry Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsCompositionOfPortfolioAtFairValueByControlDesignationInvestmentTypeAndIndustry CONSOLIDATED SCHEDULE OF INVESTMENTS - Composition of Portfolio at Fair Value by Control Designation, Investment Type and Industry Statements 15 false false R16.htm 100160 - Statement - CONSOLIDATED SCHEDULE OF INVESTMENTS - Summary of Percentage of Total Investment Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsSummaryOfPercentageOfTotalInvestment CONSOLIDATED SCHEDULE OF INVESTMENTS - Summary of Percentage of Total Investment Statements 16 false false R17.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 17 false false R18.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 18 false false R19.htm 995455 - Disclosure - Cybersecurity Risk Management, Strategy, and Governance Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance Cybersecurity Risk Management, Strategy, and Governance Notes 19 false false R20.htm 995465 - Disclosure - Organization Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureOrganization Organization Notes 20 false false R21.htm 995470 - Disclosure - N-2 Sheet http://xbrl.sec.gov/cef/role/N2 N-2 Notes 21 false false R22.htm 995475 - Disclosure - Significant Accounting Policies Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureSignificantAccountingPolicies Significant Accounting Policies Notes 22 false false R23.htm 995485 - Disclosure - Change in Year End Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureChangeInYearEnd Change in Year End Notes 23 false false R24.htm 995495 - Disclosure - Related Party Agreements and Transactions Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureRelatedPartyAgreementsAndTransactions Related Party Agreements and Transactions Notes 24 false false R25.htm 995505 - Disclosure - Earnings Per Share Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureEarningsPerShare Earnings Per Share Notes 25 false false R26.htm 995515 - Disclosure - Investments Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestments Investments Notes 26 false false R27.htm 995525 - Disclosure - Debt and Foreign Currency Transactions and Translations Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslations Debt and Foreign Currency Transactions and Translations Notes 27 false false R28.htm 995535 - Disclosure - Stockholders' Equity Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureStockholdersEquity Stockholders' Equity Notes 28 false false R29.htm 995545 - Disclosure - Commitments and Contingencies Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureCommitmentsAndContingencies Commitments and Contingencies Notes 29 false false R30.htm 995555 - Disclosure - Income Taxes Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxes Income Taxes Notes 30 false false R31.htm 995565 - Disclosure - Financial Highlights Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureFinancialHighlights Financial Highlights Notes 31 false false R32.htm 995585 - Disclosure - Senior Securities Table Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureSeniorSecuritiesTable Senior Securities Table Notes 32 false false R33.htm 995595 - Disclosure - Mergers with AFT and AIF Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureMergersWithAftAndAif Mergers with AFT and AIF Notes 33 false false R34.htm 995615 - Disclosure - Subsequent Events Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureSubsequentEvents Subsequent Events Notes 34 false false R35.htm 995625 - Disclosure - Significant Accounting Policies (Policies) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureSignificantAccountingPoliciesPolicies Significant Accounting Policies (Policies) Policies http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureSignificantAccountingPolicies 35 false false R36.htm 995635 - Disclosure - Earnings Per Share (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureEarningsPerShareTables Earnings Per Share (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureEarningsPerShare 36 false false R37.htm 995645 - Disclosure - Investments (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsTables Investments (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestments 37 false false R38.htm 995655 - Disclosure - Debt and Foreign Currency Transactions and Translations (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsTables Debt and Foreign Currency Transactions and Translations (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslations 38 false false R39.htm 995665 - Disclosure - Stockholders' Equity (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureStockholdersEquityTables Stockholders' Equity (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureStockholdersEquity 39 false false R40.htm 995675 - Disclosure - Commitments and Contingencies (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesTables Commitments and Contingencies (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureCommitmentsAndContingencies 40 false false R41.htm 995685 - Disclosure - Income Taxes (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxesTables Income Taxes (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxes 41 false false R42.htm 995695 - Disclosure - Financial Highlights (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureFinancialHighlightsTables Financial Highlights (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureFinancialHighlights 42 false false R43.htm 995715 - Disclosure - Senior Securities Table (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureSeniorSecuritiesTableTables Senior Securities Table (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureSeniorSecuritiesTable 43 false false R44.htm 995725 - Disclosure - Mergers with AFT and AIF (Tables) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureMergersWithAftAndAifTables Mergers with AFT and AIF (Tables) Tables http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureMergersWithAftAndAif 44 false false R45.htm 995735 - Disclosure - Organization - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureOrganizationAdditionalInformationDetails Organization - Additional Information (Details) Details 45 false false R46.htm 995745 - Disclosure - Significant Accounting Policies - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureSignificantAccountingPoliciesAdditionalInformationDetails Significant Accounting Policies - Additional Information (Details) Details 46 false false R47.htm 995755 - Disclosure - Related Party Agreements and Transactions - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureRelatedPartyAgreementsAndTransactionsAdditionalInformationDetails Related Party Agreements and Transactions - Additional Information (Details) Details 47 false false R48.htm 995765 - Disclosure - Earnings Per Share - Schedule of Computation of Earnings (Loss) Per Share (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureEarningsPerShareScheduleOfComputationOfEarningsLossPerShareDetails Earnings Per Share - Schedule of Computation of Earnings (Loss) Per Share (Details) Details 48 false false R49.htm 995775 - Disclosure - Investments - Schedule of Composition of Investment Portfolio (Detail) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsScheduleOfCompositionOfInvestmentPortfolioDetail Investments - Schedule of Composition of Investment Portfolio (Detail) Details 49 false false R50.htm 995785 - Disclosure - Investments - Schedule of Changes in Fair Value of Investments (Detail) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsScheduleOfChangesInFairValueOfInvestmentsDetail Investments - Schedule of Changes in Fair Value of Investments (Detail) Details 50 false false R51.htm 995795 - Disclosure - Investments - Schedule of Changes in Fair Value of Investments (Parenthetical) (Detail) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsScheduleOfChangesInFairValueOfInvestmentsParentheticalDetail Investments - Schedule of Changes in Fair Value of Investments (Parenthetical) (Detail) Details 51 false false R52.htm 995805 - Disclosure - Investments - Summary of Unobservable Inputs Used in Fair Value Measurements of Level 3 Investments (Detail) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsSummaryOfUnobservableInputsUsedInFairValueMeasurementsOfLevel3InvestmentsDetail Investments - Summary of Unobservable Inputs Used in Fair Value Measurements of Level 3 Investments (Detail) Details 52 false false R53.htm 995815 - Disclosure - Investments - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsAdditionalInformationDetails Investments - Additional Information (Details) Details 53 false false R54.htm 995825 - Disclosure - Investments - Summary of Change in Capitalized PIK balance (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureInvestmentsSummaryOfChangeInCapitalizedPIKBalanceDetails Investments - Summary of Change in Capitalized PIK balance (Details) Details 54 false false R55.htm 995835 - Disclosure - Investments - Summarized Financial Information of Subsidiary (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureInvestmentsSummarizedFinancialInformationOfSubsidiaryDetails Investments - Summarized Financial Information of Subsidiary (Details) Details 55 false false R56.htm 995845 - Disclosure - Debt and Foreign Currency Transactions and Translations - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsAdditionalInformationDetails Debt and Foreign Currency Transactions and Translations - Additional Information (Details) Details 56 false false R57.htm 995855 - Disclosure - Debt and Foreign Currency Transactions and Translations - Schedule of Outstanding Debt Obligations (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsScheduleOfOutstandingDebtObligationsDetails Debt and Foreign Currency Transactions and Translations - Schedule of Outstanding Debt Obligations (Details) Details 57 false false R58.htm 995865 - Disclosure - Debt and Foreign Currency Transactions and Translations - Schedule of Outstanding Debt Obligations (Parenthetical) (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsScheduleOfOutstandingDebtObligationsParentheticalDetails Debt and Foreign Currency Transactions and Translations - Schedule of Outstanding Debt Obligations (Parenthetical) (Details) Details 58 false false R59.htm 995875 - Disclosure - Debt and Foreign Currency Transactions and Translations - Summary of Secured and Unsecured Notes Issued (Details) Notes http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsSummaryOfSecuredAndUnsecuredNotesIssuedDetails Debt and Foreign Currency Transactions and Translations - Summary of Secured and Unsecured Notes Issued (Details) Details 59 false false R60.htm 995885 - Disclosure - Debt and Foreign Currency Transactions and Translations - Summarizes Average and Maximum Debt Outstanding and Interest and Debt Issuance Cost (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsSummarizesAverageAndMaximumDebtOutstandingAndInterestAndDebtIssuanceCostDetails Debt and Foreign Currency Transactions and Translations - Summarizes Average and Maximum Debt Outstanding and Interest and Debt Issuance Cost (Details) Details 60 false false R61.htm 995895 - Disclosure - Debt and Foreign Currency Transactions and Translations - Summarizes Average and Maximum Debt Outstanding and Interest and Debt Issuance Cost (Parenthetical) (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsSummarizesAverageAndMaximumDebtOutstandingAndInterestAndDebtIssuanceCostParentheticalDetails Debt and Foreign Currency Transactions and Translations - Summarizes Average and Maximum Debt Outstanding and Interest and Debt Issuance Cost (Parenthetical) (Details) Details 61 false false R62.htm 995905 - Disclosure - Debt and Foreign Currency Transactions and Translations - Summary of Foreign Denominated Debt Outstanding on Senior Secured Facility (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureDebtAndForeignCurrencyTransactionsAndTranslationsSummaryOfForeignDenominatedDebtOutstandingOnSeniorSecuredFacilityDetails Debt and Foreign Currency Transactions and Translations - Summary of Foreign Denominated Debt Outstanding on Senior Secured Facility (Details) Details 62 false false R63.htm 995915 - Disclosure - Stockholders' Equity - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureStockholdersEquityAdditionalInformationDetails Stockholders' Equity - Additional Information (Details) Details 63 false false R64.htm 995925 - Disclosure - Stockholders' Equity - Schedule of Repurchase Plans (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureStockholdersEquityScheduleOfRepurchasePlansDetails Stockholders' Equity - Schedule of Repurchase Plans (Details) Details 64 false false R65.htm 995935 - Disclosure - Stockholders' Equity - Summary of Allocated Amounts to be Repurchased (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureStockholdersEquitySummaryOfAllocatedAmountsToBeRepurchasedDetails Stockholders' Equity - Summary of Allocated Amounts to be Repurchased (Details) Details 65 false false R66.htm 995945 - Disclosure - Commitments and Contingencies - Summary of Unfunded Commitments (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesSummaryOfUnfundedCommitmentsDetails Commitments and Contingencies - Summary of Unfunded Commitments (Details) Details 66 false false R67.htm 995955 - Disclosure - Commitments and Contingencies - Summary of Unfunded Commitments (Parenthetical) (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesSummaryOfUnfundedCommitmentsParentheticalDetails Commitments and Contingencies - Summary of Unfunded Commitments (Parenthetical) (Details) Details 67 false false R68.htm 995965 - Disclosure - Income Taxes - Summary of Tax Character of Distributions Paid to Stockholders (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxesSummaryOfTaxCharacterOfDistributionsPaidToStockholdersDetails Income Taxes - Summary of Tax Character of Distributions Paid to Stockholders (Details) Details 68 false false R69.htm 995975 - Disclosure - Income Taxes - Summary of Reconciliation of Net Increase in Net Assets Resulting from Operations to Taxable Income (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxesSummaryOfReconciliationOfNetIncreaseInNetAssetsResultingFromOperationsToTaxableIncomeDetails Income Taxes - Summary of Reconciliation of Net Increase in Net Assets Resulting from Operations to Taxable Income (Details) Details 69 false false R70.htm 995985 - Disclosure - Income Taxes - Components of Accumulated Losses on Tax Basis (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxesComponentsOfAccumulatedLossesOnTaxBasisDetails Income Taxes - Components of Accumulated Losses on Tax Basis (Details) Details 70 false false R71.htm 995995 - Disclosure - Income Taxes - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails Income Taxes - Additional Information (Details) Details 71 false false R72.htm 996005 - Disclosure - Financial Highlights - Schedule of Financial Highlights (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureFinancialHighlightsScheduleOfFinancialHighlightsDetails Financial Highlights - Schedule of Financial Highlights (Details) Details 72 false false R73.htm 996015 - Disclosure - Financial Highlights - Schedule of Financial Highlights (Parenthetical) (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureFinancialHighlightsScheduleOfFinancialHighlightsParentheticalDetails Financial Highlights - Schedule of Financial Highlights (Parenthetical) (Details) Details 73 false false R74.htm 996025 - Disclosure - Selected Quarterly Financial Data (Unaudited) - Schedule of Selected Quarterly Financial Data (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureSelectedQuarterlyFinancialDataUnauditedScheduleOfSelectedQuarterlyFinancialDataDetails Selected Quarterly Financial Data (Unaudited) - Schedule of Selected Quarterly Financial Data (Details) Details 74 false false R75.htm 996035 - Disclosure - Senior Securities Table - Schedule of Information About Senior Securities (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureSeniorSecuritiesTableScheduleOfInformationAboutSeniorSecuritiesDetails Senior Securities Table - Schedule of Information About Senior Securities (Details) Details 75 false false R76.htm 996045 - Disclosure - Senior Securities Table - Schedule of Information About Senior Securities (Parenthetical) (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureSeniorSecuritiesTableScheduleOfInformationAboutSeniorSecuritiesParentheticalDetails Senior Securities Table - Schedule of Information About Senior Securities (Parenthetical) (Details) Details 76 false false R77.htm 996055 - Disclosure - Mergers with AFT and AIF - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureMergersWithAftAndAifAdditionalInformationDetails Mergers with AFT and AIF - Additional Information (Details) Details 77 false false R78.htm 996065 - Disclosure - Mergers with AFT and AIF - Summary of Allocation of Purchase Price to Assets Acquired and Liabilities Assumed (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureMergersWithAftAndAifSummaryOfAllocationOfPurchasePriceToAssetsAcquiredAndLiabilitiesAssumedDetails Mergers with AFT and AIF - Summary of Allocation of Purchase Price to Assets Acquired and Liabilities Assumed (Details) Details 78 false false R79.htm 996075 - Disclosure - Mergers with AFT and AIF - Summary of Allocation of Purchase Price to Assets Acquired and Liabilities Assumed (Parenthetical) (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/DisclosureMergersWithAftAndAifSummaryOfAllocationOfPurchasePriceToAssetsAcquiredAndLiabilitiesAssumedParentheticalDetails Mergers with AFT and AIF - Summary of Allocation of Purchase Price to Assets Acquired and Liabilities Assumed (Parenthetical) (Details) Details 79 false false R80.htm 996085 - Disclosure - Subsequent Events - Additional Information (Details) Sheet http://www.midcapfinancialic.com/20241231/taxonomy/role/Role_DisclosureSubsequentEventsAdditionalInformationDetails Subsequent Events - Additional Information (Details) Details 80 false false All Reports Book All Reports mfic-20241231.htm mfic-20241231.xsd img104413529_0.jpg http://fasb.org/srt/2024 http://fasb.org/us-gaap/2024 http://xbrl.sec.gov/cef/2024 http://xbrl.sec.gov/cyd/2024 http://xbrl.sec.gov/dei/2024 http://xbrl.sec.gov/ecd/2024 false false