000153577812-312023Q1falseP3YP5YP3YP5Y00015357782023-01-012023-03-3100015357782023-05-12xbrli:shares0001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2023-03-31iso4217:USD0001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-12-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-12-310001535778us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2023-03-310001535778us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-12-3100015357782023-03-3100015357782022-12-310001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMember2023-03-310001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMember2022-12-310001535778msif:SeriesANotesDue2026Memberus-gaap:UnsecuredDebtMember2023-03-310001535778msif:SeriesANotesDue2026Memberus-gaap:UnsecuredDebtMember2022-12-31iso4217:USDxbrli:shares0001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2023-01-012023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-01-012022-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-01-012023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-01-012022-03-310001535778us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2023-01-012023-03-310001535778us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-01-012022-03-3100015357782022-01-012022-03-310001535778us-gaap:CommonStockMember2021-12-310001535778us-gaap:AdditionalPaidInCapitalMember2021-12-310001535778us-gaap:RetainedEarningsMember2021-12-3100015357782021-12-310001535778us-gaap:CommonStockMember2022-01-012022-03-310001535778us-gaap:AdditionalPaidInCapitalMember2022-01-012022-03-310001535778us-gaap:RetainedEarningsMember2022-01-012022-03-310001535778us-gaap:CommonStockMember2022-03-310001535778us-gaap:AdditionalPaidInCapitalMember2022-03-310001535778us-gaap:RetainedEarningsMember2022-03-3100015357782022-03-310001535778us-gaap:CommonStockMember2022-12-310001535778us-gaap:AdditionalPaidInCapitalMember2022-12-310001535778us-gaap:RetainedEarningsMember2022-12-310001535778us-gaap:CommonStockMember2023-01-012023-03-310001535778us-gaap:AdditionalPaidInCapitalMember2023-01-012023-03-310001535778us-gaap:RetainedEarningsMember2023-01-012023-03-310001535778us-gaap:CommonStockMember2023-03-310001535778us-gaap:AdditionalPaidInCapitalMember2023-03-310001535778us-gaap:RetainedEarningsMember2023-03-310001535778Copper Trail Fund Investments, LP Interests (CTMH, LP)2023-03-31xbrli:pure0001535778GRT Rubber Technologies LLC, Secured Debt 12023-03-310001535778GRT Rubber Technologies LLC, Secured Debt 22023-03-310001535778GRT Rubber Technologies LLC, Member Units2023-03-310001535778msif:GRTRubberTechnologiesLLCMember2023-03-310001535778Harris Preston Fund Investments, LP Interests (2717 MH, L.P.)2023-03-310001535778AFG Capital Group, LLC, Preferred Member Units2023-03-310001535778Analytical Systems Keco Holdings, LLC, Secured Debt 12023-03-310001535778Analytical Systems Keco Holdings, LLC, Secured Debt 22023-03-310001535778Analytical Systems Keco Holdings, LLC, Preferred Member Units 12023-03-310001535778Analytical Systems Keco Holdings, LLC, Preferred Member Units 22023-03-310001535778Analytical Systems Keco Holdings, LLC, Warrants2023-03-310001535778msif:AnalyticalSystemsKecoHoldingsLLCMember2023-03-310001535778Barfly Ventures, LLC, Member Units2023-03-310001535778Batjer TopCo, LLC, Secured Debt 12023-03-310001535778Batjer TopCo, LLC, Secured Debt 22023-03-310001535778Batjer TopCo, LLC, Preferred Stock2023-03-310001535778msif:BatjerTopCoLLCMember2023-03-310001535778Brewer Crane Holdings, LLC, Secured Debt2023-03-310001535778Brewer Crane Holdings, LLC, Preferred Member Units2023-03-310001535778msif:BrewerCraneHoldingsLLCMember2023-03-310001535778Centre Technologies Holdings, LLC, Secured Debt 12023-03-310001535778Centre Technologies Holdings, LLC, Secured Debt 22023-03-310001535778Centre Technologies Holdings, LLC, Preferred Member Units2023-03-310001535778msif:CentreTechnologiesHoldingsLLCMember2023-03-310001535778Chamberlin Holding LLC, Secured Debt 12023-03-310001535778Chamberlin Holding LLC, Secured Debt 22023-03-310001535778Chamberlin Holding LLC, Member Units 12023-03-310001535778Chamberlin Holding LLC, Member Units 22023-03-310001535778msif:ChamberlinHoldingLLCMember2023-03-310001535778Charps, LLC, Preferred Member Units2023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 12023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 22023-03-310001535778Clad-Rex Steel, LLC, Member Units 12023-03-310001535778Clad-Rex Steel, LLC, Member Units 22023-03-310001535778msif:CladRexSteelLLCMember2023-03-310001535778Cody Pools, Inc., Secured Debt 12023-03-310001535778Cody Pools, Inc., Secured Debt 22023-03-310001535778Cody Pools, Inc., Preferred Member Units2023-03-310001535778msif:CodyPoolsIncMember2023-03-310001535778Colonial Electric Company LLC, Secured Debt 12023-03-310001535778Colonial Electric Company LLC, Secured Debt 22023-03-310001535778Colonial Electric Company LLC, Preferred Member Units2023-03-310001535778msif:ColonialElectricCompanyLLCMember2023-03-310001535778Datacom, LLC, Secured Debt 12023-03-310001535778Datacom, LLC, Secured Debt 22023-03-310001535778Datacom, LLC, Preferred Member Units2023-03-310001535778msif:DatacomLLCMember2023-03-310001535778Digital Products Holdings LLC, Secured Debt2023-03-310001535778Digital Products Holdings LLC, Preferred Member Units2023-03-310001535778msif:DigitalProductsHoldingsLLCMember2023-03-310001535778Direct Marketing Solutions, Inc., Secured Debt 12023-03-310001535778Direct Marketing Solutions, Inc., Secured Debt 22023-03-310001535778Direct Marketing Solutions, Inc., Preferred Stock2023-03-310001535778msif:DirectMarketingSolutionsIncMember2023-03-310001535778Flame King Holdings, LLC, Secured Debt 12023-03-310001535778Flame King Holdings, LLC, Secured Debt 22023-03-310001535778Flame King Holdings, LLC, Preferred Equity2023-03-310001535778msif:FlameKingHoldingsLLCMember2023-03-310001535778Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP)2023-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt 12023-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt 22023-03-310001535778Gamber-Johnson Holdings, LLC, Member Units2023-03-310001535778msif:GamberJohnsonHoldingsLLCMember2023-03-310001535778GFG Group, LLC., Secured Debt2023-03-310001535778GFG Group, LLC., Preferred Member Units2023-03-310001535778msif:GFGGroupLLCMember2023-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 12023-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 22023-03-310001535778Gulf Publishing Holdings, LLC, Preferred Equity2023-03-310001535778Gulf Publishing Holdings, LLC, Member Units2023-03-310001535778msif:GulfPublishingHoldingsLLCMember2023-03-310001535778Harris Preston Fund Investments, LP Interests (HPEP 3, L.P.)2023-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 12023-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 22023-03-310001535778Kickhaefer Manufacturing Company, LLC, Preferred Equity2023-03-310001535778Kickhaefer Manufacturing Company, LLC, Member Units2023-03-310001535778msif:KickhaeferManufacturingCompanyLLCMember2023-03-310001535778Market Force Information, LLC, Secured Debt2023-03-310001535778Market Force Information, LLC, Member Units2023-03-310001535778msif:MarketForceInformationLLCMember2023-03-310001535778MH Corbin Holding LLC, Secured Debt2023-03-310001535778MH Corbin Holding LLC, Preferred Member Units 12023-03-310001535778MH Corbin Holding LLC, Preferred Member Units 22023-03-310001535778msif:MHCorbinHoldingLLCMember2023-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt 12023-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt 22023-03-310001535778Mystic Logistics Holdings, LLC, Common Stock2023-03-310001535778msif:MysticLogisticsHoldingsLLCMember2023-03-310001535778NexRev LLC, Secured Debt 12023-03-310001535778NexRev LLC, Secured Debt 22023-03-310001535778NexRev LLC, Preferred Member Units2023-03-310001535778msif:NexRevLLCMember2023-03-310001535778NuStep, LLC, Secured Debt 12023-03-310001535778NuStep, LLC, Secured Debt 22023-03-310001535778NuStep, LLC, Preferred Member Units 12023-03-310001535778NuStep, LLC, Preferred Member Units 22023-03-310001535778msif:NuStepLLCMember2023-03-310001535778Oneliance, LLC, Secured Debt2023-03-310001535778Oneliance, LLC, Preferred Stock2023-03-310001535778msif:OnelianceLLCMember2023-03-310001535778Orttech Holdings, LLC, Secured Debt 12023-03-310001535778Orttech Holdings, LLC, Secured Debt 22023-03-310001535778Orttech Holdings, LLC, Preferred Stock2023-03-310001535778msif:OrttechHoldingsLLCMember2023-03-310001535778Robbins Bros. Jewelry, Inc., Secured Debt 12023-03-310001535778Robbins Bros. Jewelry, Inc., Secured Debt 22023-03-310001535778Robbins Bros. Jewelry, Inc., Preferred Equity2023-03-310001535778msif:RobbinsBrosJewelryIncMember2023-03-310001535778SI East, LLC, Secured Debt 12023-03-310001535778SI East, LLC, Secured Debt 22023-03-310001535778SI East, LLC, Preferred Member Units2023-03-310001535778msif:SIEastLLCMember2023-03-310001535778Sonic Systems International, LLC, Secured Debt2023-03-310001535778Sonic Systems International, LLC, Common Stock2023-03-310001535778msif:SonicSystemsInternationalLLCMember2023-03-310001535778Student Resource Center, LLC, Secured Debt2023-03-310001535778Student Resource Center, LLC, Preferred Equity2023-03-310001535778msif:StudentResourceCenterLLCMember2023-03-310001535778Tedder Industries, LLC, Secured Debt 12023-03-310001535778Tedder Industries, LLC, Secured Debt 22023-03-310001535778Tedder Industries, LLC, Preferred Member Units 12023-03-310001535778Tedder Industries, LLC, Preferred Member Units 22023-03-310001535778msif:TedderIndustriesLLCMember2023-03-310001535778Trantech Radiator Topco, LLC, Secured Debt 12023-03-310001535778Trantech Radiator Topco, LLC, Secured Debt 22023-03-310001535778Trantech Radiator Topco, LLC, Common Stock2023-03-310001535778msif:TrantechRadiatorTopcoLLCMember2023-03-310001535778Volusion, LLC, Secured Debt2023-03-310001535778Volusion, LLC, Preferred Member Units 12023-03-310001535778Volusion, LLC, Preferred Member Units 22023-03-310001535778Volusion, LLC, Preferred Member Units 32023-03-310001535778Volusion, LLC, Common Stock2023-03-310001535778msif:VolusionLLCMember2023-03-310001535778VVS Holdco LLC, Secured Debt 12023-03-310001535778VVS Holdco LLC, Secured Debt 22023-03-310001535778VVS Holdco LLC, Preferred Equity2023-03-310001535778msif:VVSHoldcoLLCMember2023-03-310001535778AAC Holdings, Inc., Secured Debt 12023-03-310001535778AAC Holdings, Inc., Secured Debt 22023-03-310001535778AAC Holdings, Inc., Common Stock2023-03-310001535778AAC Holdings, Inc., Warrants2023-03-310001535778msif:AACHoldingsIncMember2023-03-310001535778AB Centers Acquisition Corporation, Secured Debt 12023-03-310001535778AB Centers Acquisition Corporation, Secured Debt 22023-03-310001535778AB Centers Acquisition Corporation, Secured Debt 32023-03-310001535778msif:ABCentersAcquisitionCorporationMember2023-03-310001535778Acumera, Inc., Secured Debt 12023-03-310001535778Acumera, Inc., Secured Debt 22023-03-310001535778Acumera, Inc., Secured Debt 32023-03-310001535778Acumera, Inc., Warrants2023-03-310001535778msif:AcumeraIncMember2023-03-310001535778Adams Publishing Group, LLC, Secured Debt 12023-03-310001535778Adams Publishing Group, LLC, Secured Debt 22023-03-310001535778msif:AdamsPublishingGroupLLCMember2023-03-310001535778ADS Tactical, Inc., Secured Debt2023-03-310001535778AMEREQUIP LLC., Secured Debt 12023-03-310001535778AMEREQUIP LLC., Secured Debt 22023-03-310001535778AMEREQUIP LLC., Common Stock2023-03-310001535778msif:AMEREQUIPLLCMember2023-03-310001535778American Health Staffing Group, Inc., Secured Debt 12023-03-310001535778American Health Staffing Group, Inc., Secured Debt 22023-03-310001535778msif:AmericanHealthStaffingGroupIncMember2023-03-310001535778American Nuts, LLC, Secured Debt 12023-03-310001535778American Nuts, LLC, Secured Debt 22023-03-310001535778msif:AmericanNutsLLCMember2023-03-310001535778American Teleconferencing Services, Ltd., Secured Debt 12023-03-310001535778American Teleconferencing Services, Ltd., Secured Debt 22023-03-310001535778msif:AmericanTeleconferencingServicesLtdMember2023-03-310001535778ArborWorks, LLC, Secured Debt 12023-03-310001535778ArborWorks, LLC, Secured Debt 22023-03-310001535778ArborWorks, LLC, Common Equity2023-03-310001535778msif:ArborWorksLLCMember2023-03-310001535778Archer Systems, LLC, Secured Debt 12023-03-310001535778Archer Systems, LLC, Secured Debt 22023-03-310001535778Archer Systems, LLC, Common Stock2023-03-310001535778msif:ArcherSystemsLLCMember2023-03-310001535778ATS Operating, LLC, Secured Debt 12023-03-310001535778ATS Operating, LLC, Secured Debt 22023-03-310001535778ATS Operating, LLC, Secured Debt 32023-03-310001535778ATS Operating, LLC, Common Stock2023-03-310001535778msif:ATSOperatingLLCMember2023-03-310001535778AVEX Aviation Holdings, LLC, Secured Debt 12023-03-310001535778AVEX Aviation Holdings, LLC, Secured Debt 22023-03-310001535778AVEX Aviation Holdings, LLC, Common Equity2023-03-310001535778msif:AVEXAviationHoldingsLLCMember2023-03-310001535778BBB Tank Services, LLC, Unsecured Debt 12023-03-310001535778BBB Tank Services, LLC, Unsecured Debt 22023-03-310001535778BBB Tank Services, LLC, Member Units2023-03-310001535778BBB Tank Services, LLC, Preferred Stock (non-voting)2023-03-310001535778msif:BBBTankServicesLLCMember2023-03-310001535778Berry Aviation, Inc., Secured Debt2023-03-310001535778Berry Aviation, Inc., Preferred Member Units 12023-03-310001535778Berry Aviation, Inc., Preferred Member Units 22023-03-310001535778msif:BerryAviationIncMember2023-03-310001535778Bettercloud, Inc., Secured Debt 12023-03-310001535778Bettercloud, Inc., Secured Debt 22023-03-310001535778msif:BettercloudIncMember2023-03-310001535778Binswanger Enterprises, LLC, Member Units2023-03-310001535778Bluestem Brands, Inc., Secured Debt 12023-03-310001535778Bluestem Brands, Inc., Secured Debt 22023-03-310001535778Bluestem Brands, Inc., Common Stock2023-03-310001535778Bluestem Brands, Inc., Warrants2023-03-310001535778msif:BluestemBrandsIncMember2023-03-310001535778Boccella Precast Products LLC, Secured Debt2023-03-310001535778Boccella Precast Products LLC, Member Units2023-03-310001535778msif:BoccellaPrecastProductsLLCMember2023-03-310001535778Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund III, LP)2023-03-310001535778Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund IV, LP)2023-03-310001535778msif:BrightwoodCapitalFundInvestmentsMember2023-03-310001535778Buca C, LLC, Secured Debt2023-03-310001535778Buca C, LLC, Preferred Member Units2023-03-310001535778msif:BucaCLLCMember2023-03-310001535778Burning Glass Intermediate Holding Company, Inc., Secured Debt 12023-03-310001535778Burning Glass Intermediate Holding Company, Inc., Secured Debt 22023-03-310001535778msif:BurningGlassIntermediateHoldingCompanyIncMember2023-03-310001535778Cadence Aerospace LLC, Secured Debt 12023-03-310001535778Cadence Aerospace LLC, Secured Debt 22023-03-310001535778Cadence Aerospace LLC, Secured Debt 32023-03-310001535778Cadence Aerospace LLC, Secured Debt 42023-03-310001535778Cadence Aerospace LLC, Secured Debt 52023-03-310001535778msif:CadenceAerospaceLLCMember2023-03-310001535778CAI Software LLC, Preferred Equity 12023-03-310001535778CAI Software LLC, Preferred Equity 22023-03-310001535778msif:CAISoftwareLLCMember2023-03-310001535778Camin Cargo Control, Inc., Secured Debt2023-03-310001535778Career Team Holdings, LLC, Secured Debt 12023-03-310001535778Career Team Holdings, LLC, Secured Debt 22023-03-310001535778Career Team Holdings, LLC, Common Stock2023-03-310001535778msif:CareerTeamHoldingsLLCMember2023-03-310001535778CaseWorthy, Inc., Secured Debt 12023-03-310001535778CaseWorthy, Inc., Secured Debt 22023-03-310001535778CaseWorthy, Inc., Secured Debt 32023-03-310001535778CaseWorthy, Inc., Common Equity2023-03-310001535778msif:CaseWorthyIncMember2023-03-310001535778Channel Partners Intermediateco, LLC, Secured Debt 12023-03-310001535778Channel Partners Intermediateco, LLC, Secured Debt 22023-03-310001535778Channel Partners Intermediateco, LLC, Secured Debt 32023-03-310001535778msif:ChannelPartnersIntermediatecoLLCMember2023-03-310001535778Clarius BIGS, LLC, Secured Debt2023-03-310001535778Classic H&G Holdings, LLC, Secured Debt 12023-03-310001535778Classic H&G Holdings, LLC, Secured Debt 22023-03-310001535778Classic H&G Holdings, LLC, Preferred Member Units2023-03-310001535778msif:ClassicHGHoldingsLLCMember2023-03-310001535778Computer Data Source, LLC, Secured Debt 12023-03-310001535778Computer Data Source, LLC, Secured Debt 22023-03-310001535778msif:ComputerDataSourceLLCMember2023-03-310001535778Construction Supply Investments, LLC, Member Units2023-03-310001535778Dalton US Inc., Secured Debt 12023-03-310001535778Dalton US Inc., Secured Debt 22023-03-310001535778Dalton US Inc., Secured Debt 32023-03-310001535778Dalton US Inc., Common Stock2023-03-310001535778msif:DaltonUSIncMember2023-03-310001535778DMA Industries, LLC, Secured Debt2023-03-310001535778DMA Industries, LLC, Preferred Equity2023-03-310001535778msif:DMAIndustriesLLCMember2023-03-310001535778DTE Enterprises, LLC, Secured Debt 12023-03-310001535778DTE Enterprises, LLC, Secured Debt 22023-03-310001535778DTE Enterprises, LLC, Class A Preferred Member Units2023-03-310001535778DTE Enterprises, LLC, Class AA Preferred Member Units (non-voting)2023-03-310001535778msif:DTEEnterprisesLLCMember2023-03-310001535778Dynamic Communities, LLC, Secured Debt 12023-03-310001535778Dynamic Communities, LLC, Secured Debt 22023-03-310001535778Dynamic Communities, LLC, Preferred Equity 12023-03-310001535778Dynamic Communities, LLC, Preferred Equity 22023-03-310001535778Dynamic Communities, LLC, Common Equity2023-03-310001535778msif:DynamicCommunitiesLLCMember2023-03-310001535778Elgin AcquireCo, LLC, Secured Debt 12023-03-310001535778Elgin AcquireCo, LLC, Secured Debt 22023-03-310001535778Elgin AcquireCo, LLC, Secured Debt 32023-03-310001535778Elgin AcquireCo, LLC, Common Stock 12023-03-310001535778Elgin AcquireCo, LLC, Common Stock 22023-03-310001535778msif:ElginAcquireCoLLCMember2023-03-310001535778Emerald Technologies Acquisition Co, Inc., Secured Debt2023-03-310001535778Engineering Research & Consulting, LLC, Secured Debt 12023-03-310001535778Engineering Research & Consulting, LLC, Secured Debt 22023-03-310001535778msif:EngineeringResearchConsultingLLCMember2023-03-310001535778EPIC Y-Grade Services, LP, Secured Debt2023-03-310001535778Event Holdco, LLC, Secured Debt 12023-03-310001535778Event Holdco, LLC, Secured Debt 22023-03-310001535778msif:EventHoldcoLLCMember2023-03-310001535778Flip Electronics LLC, Secured Debt 12023-03-310001535778Flip Electronics LLC, Secured Debt 22023-03-310001535778msif:FlipElectronicsLLCMember2023-03-310001535778Hawk Ridge Systems, LLC, Secured Debt 12023-03-310001535778Hawk Ridge Systems, LLC, Secured Debt 22023-03-310001535778Hawk Ridge Systems, LLC, Preferred Member Units 12023-03-310001535778Hawk Ridge Systems, LLC, Preferred Member Units 22023-03-310001535778msif:HawkRidgeSystemsLLCMember2023-03-310001535778HDC/HW Intermediate Holdings, Secured Debt 12023-03-310001535778HDC/HW Intermediate Holdings, Secured Debt 22023-03-310001535778msif:HDCHWIntermediateHoldingsMember2023-03-310001535778HEADLANDS OP-CO LLC, Secured Debt 12023-03-310001535778HEADLANDS OP-CO LLC, Secured Debt 22023-03-310001535778HEADLANDS OP-CO LLC, Secured Debt 32023-03-310001535778msif:HEADLANDSOPCOLLCMember2023-03-310001535778Hybrid Promotions, LLC, Secured Debt2023-03-310001535778IG Parent Corporation, Secured Debt 12023-03-310001535778IG Parent Corporation, Secured Debt 22023-03-310001535778msif:IGParentCorporationMember2023-03-310001535778Implus Footcare, LLC, Secured Debt2023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Secured Debt 12023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Secured Debt 22023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Secured Debt 32023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) 12023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) 22023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Member Units2023-03-310001535778Independent Pet Partners Intermediate Holdings, LLC, Warrants2023-03-310001535778msif:IndependentPetPartnersIntermediateHoldingsLLCMember2023-03-310001535778Industrial Services Acquisition, LLC, Secured Debt 12023-03-310001535778Industrial Services Acquisition, LLC, Secured Debt 22023-03-310001535778Industrial Services Acquisition, LLC, Preferred Member Units 12023-03-310001535778Industrial Services Acquisition, LLC, Preferred Member Units 22023-03-310001535778Industrial Services Acquisition, LLC, Member Units2023-03-310001535778msif:IndustrialServicesAcquisitionLLCMember2023-03-310001535778Infinity X1 Holdings, LLC, Secured Debt2023-03-310001535778Infinity X1 Holdings, LLC, Preferred Equity2023-03-310001535778msif:InfinityX1HoldingsLLCMember2023-03-310001535778Infolinks Media Buyco, LLC, Secured Debt 12023-03-310001535778Infolinks Media Buyco, LLC, Secured Debt 22023-03-310001535778msif:InfolinksMediaBuycoLLCMember2023-03-310001535778Interface Security Systems, L.L.C, Secured Debt 22023-03-310001535778Interface Security Systems, L.L.C, Secured Debt 32023-03-310001535778Interface Security Systems, L.L.C, Common Stock2023-03-310001535778msif:InterfaceSecuritySystemsLLCMember2023-03-310001535778Intermedia Holdings, Inc., Secured Debt2023-03-310001535778Invincible Boat Company, LLC., Secured Debt 12023-03-310001535778Invincible Boat Company, LLC., Secured Debt 22023-03-310001535778msif:InvincibleBoatCompanyLLCMember2023-03-310001535778INW Manufacturing, LLC, Secured Debt2023-03-310001535778Iron-Main Investments, LLC, Secured Debt 12023-03-310001535778Iron-Main Investments, LLC, Secured Debt 22023-03-310001535778Iron-Main Investments, LLC, Secured Debt 32023-03-310001535778Iron-Main Investments, LLC, Secured Debt 42023-03-310001535778Iron-Main Investments, LLC, Secured Debt 52023-03-310001535778Iron-Main Investments, LLC, Common Stock2023-03-310001535778msif:IronMainInvestmentsLLCMember2023-03-310001535778Isagenix International, LLC, Secured Debt2023-03-310001535778Jackmont Hospitality, Inc., Secured Debt 12023-03-310001535778Jackmont Hospitality, Inc., Secured Debt 22023-03-310001535778Jackmont Hospitality, Inc., Preferred Equity2023-03-310001535778msif:JackmontHospitalityIncMember2023-03-310001535778Joerns Healthcare, LLC, Secured Debt 12023-03-310001535778Joerns Healthcare, LLC, Secured Debt 22023-03-310001535778Joerns Healthcare, LLC, Common Stock2023-03-310001535778msif:JoernsHealthcareLLCMember2023-03-310001535778Johnson Downie Opco, LLC, Secured Debt 12023-03-310001535778Johnson Downie Opco, LLC, Secured Debt 22023-03-310001535778Johnson Downie Opco, LLC, Preferred Equity2023-03-310001535778msif:JohnsonDownieOpcoLLCMember2023-03-310001535778JorVet Holdings, LLC, Secured Debt2023-03-310001535778JorVet Holdings, LLC, Preferred Equity2023-03-310001535778msif:JorVetHoldingsLLCMember2023-03-310001535778JTI Electrical & Mechanical, LLC, Secured Debt 12023-03-310001535778JTI Electrical & Mechanical, LLC, Secured Debt 22023-03-310001535778JTI Electrical & Mechanical, LLC, Common Equity2023-03-310001535778msif:JTIElectricalMechanicalLLCMember2023-03-310001535778KMS, LLC, Secured Debt 12023-03-310001535778KMS, LLC, Secured Debt 22023-03-310001535778msif:KMSLLCMember2023-03-310001535778Lightbox Holdings, L.P., Secured Debt2023-03-310001535778LL Management, Inc., Secured Debt 12023-03-310001535778LL Management, Inc., Secured Debt 22023-03-310001535778LL Management, Inc., Secured Debt 32023-03-310001535778msif:LLManagementIncMember2023-03-310001535778LLFlex, LLC, Secured Debt2023-03-310001535778Logix Acquisition Company, LLC, Secured Debt2023-03-310001535778Mako Steel, LP, Secured Debt 12023-03-310001535778Mako Steel, LP, Secured Debt 22023-03-310001535778msif:MakoSteelLPMember2023-03-310001535778MB2 Dental Solutions, LLC, Secured Debt 12023-03-310001535778MB2 Dental Solutions, LLC, Secured Debt 22023-03-310001535778msif:MB2DentalSolutionsLLCMember2023-03-310001535778MetalForming AcquireCo, LLC, Secured Debt 12023-03-310001535778MetalForming AcquireCo, LLC, Secured Debt 22023-03-310001535778MetalForming AcquireCo, LLC, Preferred Equity2023-03-310001535778MetalForming AcquireCo, LLC, Common Stock2023-03-310001535778msif:MetalFormingAcquireCoLLCMember2023-03-310001535778Microbe Formulas, LLC, Secured Debt 12023-03-310001535778Microbe Formulas, LLC, Secured Debt 22023-03-310001535778msif:MicrobeFormulasLLCMember2023-03-310001535778Mills Fleet Farm Group, LLC, Secured Debt2023-03-310001535778MonitorUS Holding, LLC, Secured Debt 12023-03-310001535778MonitorUS Holding, LLC, Secured Debt 22023-03-310001535778MonitorUS Holding, LLC, Secured Debt 32023-03-310001535778MonitorUS Holding, LLC, Common Stock2023-03-310001535778msif:MonitorUSHoldingLLCMember2023-03-310001535778NinjaTrader, LLC, Secured Debt 12023-03-310001535778NinjaTrader, LLC, Secured Debt 22023-03-310001535778NinjaTrader, LLC, Secured Debt 32023-03-310001535778msif:NinjaTraderLLCMember2023-03-310001535778NTM Acquisition Corp., Secured Debt2023-03-310001535778NWN Corporation, Secured Debt 12023-03-310001535778NWN Corporation, Secured Debt 22023-03-310001535778NWN Corporation, Secured Debt 32023-03-310001535778msif:NWNCorporationMember2023-03-310001535778OVG Business Services, LLC, Secured Debt2023-03-310001535778Paragon Healthcare, Inc., Secured Debt 12023-03-310001535778Paragon Healthcare, Inc., Secured Debt 22023-03-310001535778Paragon Healthcare, Inc., Secured Debt 32023-03-310001535778msif:ParagonHealthcareIncMember2023-03-310001535778PTL US Bidco, Inc, Secured Debt 12023-03-310001535778PTL US Bidco, Inc, Secured Debt 22023-03-310001535778msif:PTLUSBidcoIncMember2023-03-310001535778RA Outdoors LLC, Secured Debt 12023-03-310001535778RA Outdoors LLC, Secured Debt 22023-03-310001535778msif:RAOutdoorsLLCMember2023-03-310001535778Research Now Group, Inc. and Survey Sampling International, LLC, Secured Debt2023-03-310001535778RM Bidder, LLC, Member Units2023-03-310001535778RM Bidder, LLC, Warrants2023-03-310001535778msif:RMBidderLLCMember2023-03-310001535778Roof Opco, LLC, Secured Debt 12023-03-310001535778Roof Opco, LLC, Secured Debt 22023-03-310001535778Roof Opco, LLC, Secured Debt 32023-03-310001535778msif:RoofOpcoLLCMember2023-03-310001535778Rug Doctor, LLC., Secured Debt 12023-03-310001535778Rug Doctor, LLC., Secured Debt 22023-03-310001535778msif:RugDoctorLLCMember2023-03-310001535778Savers, Inc., Secured Debt2023-03-310001535778SIB Holdings, LLC, Secured Debt 12023-03-310001535778SIB Holdings, LLC, Secured Debt 22023-03-310001535778SIB Holdings, LLC, Secured Debt 32023-03-310001535778SIB Holdings, LLC, Common Equity2023-03-310001535778msif:SIBHoldingsLLCMember2023-03-310001535778Slick Innovations, LLC, Secured Debt2023-03-310001535778Slick Innovations, LLC, Common Stock2023-03-310001535778msif:SlickInnovationsLLCMember2023-03-310001535778South Coast Terminals Holdings, LLC, Secured Debt 12023-03-310001535778South Coast Terminals Holdings, LLC, Secured Debt 22023-03-310001535778South Coast Terminals Holdings, LLC, Common Equity2023-03-310001535778msif:SouthCoastTerminalsHoldingsLLCMember2023-03-310001535778SPAU Holdings, LLC, Secured Debt 12023-03-310001535778SPAU Holdings, LLC, Secured Debt 22023-03-310001535778SPAU Holdings, LLC, Common Stock2023-03-310001535778msif:SPAUHoldingsLLCMember2023-03-310001535778Tex Tech Tennis, LLC, Preferred Equity2023-03-310001535778The Affiliati Network, LLC, Secured Debt 12023-03-310001535778The Affiliati Network, LLC, Secured Debt 22023-03-310001535778The Affiliati Network, LLC, Preferred Stock2023-03-310001535778msif:TheAffiliatiNetworkLLCMember2023-03-310001535778U.S. TelePacific Corp., Secured Debt2023-03-310001535778USA DeBusk LLC, Secured Debt2023-03-310001535778UserZoom Technologies, Inc., Secured Debt2023-03-310001535778Vida Capital, Inc, Secured Debt2023-03-310001535778Vistar Media, Inc., Preferred Stock2023-03-310001535778VORTEQ Coil Finishers, LLC, Common Equity2023-03-310001535778Wall Street Prep, Inc., Secured Debt 12023-03-310001535778Wall Street Prep, Inc., Secured Debt 22023-03-310001535778Wall Street Prep, Inc., Common Stock2023-03-310001535778msif:WallStreetPrepIncMember2023-03-310001535778Watterson Brands, LLC, Secured Debt 12023-03-310001535778Watterson Brands, LLC, Secured Debt 22023-03-310001535778Watterson Brands, LLC, Secured Debt 32023-03-310001535778msif:WattersonBrandsLLCMember2023-03-310001535778West Star Aviation Acquisition, LLC, Secured Debt 12023-03-310001535778West Star Aviation Acquisition, LLC, Secured Debt 22023-03-310001535778West Star Aviation Acquisition, LLC, Common Stock2023-03-310001535778msif:WestStarAviationAcquisitionLLCMember2023-03-310001535778Winter Services LLC, Secured Debt 12023-03-310001535778Winter Services LLC, Secured Debt 22023-03-310001535778Winter Services LLC, Secured Debt 32023-03-310001535778msif:WinterServicesLLCMember2023-03-310001535778World Micro Holdings, LLC, Secured Debt2023-03-310001535778World Micro Holdings, LLC, Preferred Equity2023-03-310001535778msif:WorldMicroHoldingsLLCMember2023-03-310001535778Xenon Arc, Inc., Secured Debt 12023-03-310001535778Xenon Arc, Inc., Secured Debt 22023-03-310001535778Xenon Arc, Inc., Secured Debt2023-03-310001535778msif:XenonArcIncMember2023-03-310001535778YS Garments, LLC, Secured Debt2023-03-310001535778Zips Car Wash, LLC, Secured Debt 12023-03-310001535778Zips Car Wash, LLC, Secured Debt 22023-03-310001535778msif:ZipsCarWashLLCMember2023-03-310001535778First American Treasury Obligations Fund Class Z2023-03-310001535778US Bank Money Market2023-03-310001535778us-gaap:MoneyMarketFundsMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFROvernightIndexSwapRateOrLondonInterbankOfferedRateLIBORMembersrt:MinimumMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFROvernightIndexSwapRateOrLondonInterbankOfferedRateLIBORMembersrt:MaximumMember2023-03-310001535778srt:WeightedAverageMembermsif:SecuredOvernightFinancingRateSOFROvernightIndexSwapRateOrLondonInterbankOfferedRateLIBORMember2023-03-310001535778srt:MinimumMember2023-03-310001535778srt:MaximumMember2023-03-310001535778RM Bidder, LLC, Warrants2023-01-012023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:MB2DentalSolutionsLLCMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ABCentersAcquisitionCorporationMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ChannelPartnersIntermediatecoLLCMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ParagonHealthcareIncMember2023-03-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembermsif:CadenceAerospaceLLCMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:MakoSteelLPMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:DaltonUSIncMember2023-03-310001535778msif:InvincibleBoatCompanyLLCMemberus-gaap:LondonInterbankOfferedRateLIBORMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ZipsCarWashLLCMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:LLManagementIncMember2023-03-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:NWNCorporationMember2023-03-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembermsif:WattersonBrandsLLCMember2023-03-310001535778Copper Trail Fund Investments, LP Interests (CTMH, LP)2022-12-310001535778GRT Rubber Technologies LLC, Secured Debt 12022-12-310001535778GRT Rubber Technologies LLC, Secured Debt 22022-12-310001535778GRT Rubber Technologies LLC, Member Units2022-12-310001535778msif:GRTRubberTechnologiesLLCMember2022-12-310001535778Harris Preston Fund Investments, LP Interests (2717 MH, L.P.)2022-12-310001535778AFG Capital Group, LLC, Preferred Member Units2022-12-310001535778Analytical Systems Keco Holdings, LLC, Secured Debt 12022-12-310001535778Analytical Systems Keco Holdings, LLC, Secured Debt 22022-12-310001535778Analytical Systems Keco Holdings, LLC, Preferred Member Units 12022-12-310001535778Analytical Systems Keco Holdings, LLC, Preferred Member Units 22022-12-310001535778Analytical Systems Keco Holdings, LLC, Warrants2022-12-310001535778msif:AnalyticalSystemsKecoHoldingsLLCMember2022-12-310001535778ATX Networks Corp., Secured Debt2022-12-310001535778ATX Networks Corp., Unsecured Debt2022-12-310001535778ATX Networks Corp., Common Stock2022-12-310001535778msif:ATXNetworksCorpMember2022-12-310001535778Barfly Ventures, LLC, Member Units2022-12-310001535778Batjer TopCo, LLC, Secured Debt 12022-12-310001535778Batjer TopCo, LLC, Secured Debt 22022-12-310001535778Batjer TopCo, LLC, Preferred Stock2022-12-310001535778msif:BatjerTopCoLLCMember2022-12-310001535778Brewer Crane Holdings, LLC, Secured Debt2022-12-310001535778Brewer Crane Holdings, LLC, Preferred Member Units2022-12-310001535778msif:BrewerCraneHoldingsLLCMember2022-12-310001535778Centre Technologies Holdings, LLC, Secured Debt 12022-12-310001535778Centre Technologies Holdings, LLC, Secured Debt 22022-12-310001535778Centre Technologies Holdings, LLC, Preferred Member Units2022-12-310001535778msif:CentreTechnologiesHoldingsLLCMember2022-12-310001535778Chamberlin Holding LLC, Secured Debt 12022-12-310001535778Chamberlin Holding LLC, Secured Debt 22022-12-310001535778Chamberlin Holding LLC, Member Units 12022-12-310001535778Chamberlin Holding LLC, Member Units 22022-12-310001535778msif:ChamberlinHoldingLLCMember2022-12-310001535778Charps, LLC, Preferred Member Units2022-12-310001535778Clad-Rex Steel, LLC, Secured Debt 12022-12-310001535778Clad-Rex Steel, LLC, Secured Debt 22022-12-310001535778Clad-Rex Steel, LLC, Member Units 12022-12-310001535778Clad-Rex Steel, LLC, Member Units 22022-12-310001535778msif:CladRexSteelLLCMember2022-12-310001535778Cody Pools, Inc., Secured Debt 12022-12-310001535778Cody Pools, Inc., Secured Debt 22022-12-310001535778Cody Pools, Inc., Preferred Member Units2022-12-310001535778msif:CodyPoolsIncMember2022-12-310001535778Colonial Electric Company LLC, Secured Debt 12022-12-310001535778Colonial Electric Company LLC, Secured Debt 22022-12-310001535778Colonial Electric Company LLC, Preferred Member Units2022-12-310001535778msif:ColonialElectricCompanyLLCMember2022-12-310001535778Datacom, LLC, Secured Debt 12022-12-310001535778Datacom, LLC, Secured Debt 22022-12-310001535778Datacom, LLC, Preferred Member Units2022-12-310001535778msif:DatacomLLCMember2022-12-310001535778Digital Products Holdings LLC, Secured Debt2022-12-310001535778Digital Products Holdings LLC, Preferred Member Units2022-12-310001535778msif:DigitalProductsHoldingsLLCMember2022-12-310001535778Direct Marketing Solutions, Inc., Secured Debt 12022-12-310001535778Direct Marketing Solutions, Inc., Secured Debt 22022-12-310001535778Direct Marketing Solutions, Inc., Preferred Stock2022-12-310001535778msif:DirectMarketingSolutionsIncMember2022-12-310001535778Flame King Holdings, LLC, Secured Debt 12022-12-310001535778Flame King Holdings, LLC, Secured Debt 22022-12-310001535778Flame King Holdings, LLC, Preferred Equity2022-12-310001535778msif:FlameKingHoldingsLLCMember2022-12-310001535778Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP)2022-12-310001535778Gamber-Johnson Holdings, LLC, Secured Debt 12022-12-310001535778Gamber-Johnson Holdings, LLC, Secured Debt 22022-12-310001535778Gamber-Johnson Holdings, LLC, Member Units2022-12-310001535778msif:GamberJohnsonHoldingsLLCMember2022-12-310001535778GFG Group, LLC., Secured Debt2022-12-310001535778GFG Group, LLC., Preferred Member Units2022-12-310001535778msif:GFGGroupLLCMember2022-12-310001535778Gulf Publishing Holdings, LLC, Secured Debt 12022-12-310001535778Gulf Publishing Holdings, LLC, Secured Debt 22022-12-310001535778Gulf Publishing Holdings, LLC, Preferred Equity2022-12-310001535778Gulf Publishing Holdings, LLC, Member Units2022-12-310001535778msif:GulfPublishingHoldingsLLCMember2022-12-310001535778Harris Preston Fund Investments, LP Interests (HPEP 3, L.P.)2022-12-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 12022-12-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 22022-12-310001535778Kickhaefer Manufacturing Company, LLC, Preferred Equity2022-12-310001535778Kickhaefer Manufacturing Company, LLC, Member Units2022-12-310001535778msif:KickhaeferManufacturingCompanyLLCMember2022-12-310001535778Market Force Information, LLC, Secured Debt2022-12-310001535778Market Force Information, LLC, Member Units2022-12-310001535778msif:MarketForceInformationLLCMember2022-12-310001535778MH Corbin Holding LLC, Secured Debt2022-12-310001535778MH Corbin Holding LLC, Preferred Member Units 12022-12-310001535778MH Corbin Holding LLC, Preferred Member Units 22022-12-310001535778msif:MHCorbinHoldingLLCMember2022-12-310001535778Mystic Logistics Holdings, LLC, Secured Debt 12022-12-310001535778Mystic Logistics Holdings, LLC, Secured Debt 22022-12-310001535778Mystic Logistics Holdings, LLC, Common Stock2022-12-310001535778msif:MysticLogisticsHoldingsLLCMember2022-12-310001535778NexRev LLC, Secured Debt 12022-12-310001535778NexRev LLC, Secured Debt 22022-12-310001535778NexRev LLC, Preferred Member Units2022-12-310001535778msif:NexRevLLCMember2022-12-310001535778NuStep, LLC, Secured Debt 12022-12-310001535778NuStep, LLC, Secured Debt 22022-12-310001535778NuStep, LLC, Preferred Member Units 12022-12-310001535778NuStep, LLC, Preferred Member Units 22022-12-310001535778msif:NuStepLLCMember2022-12-310001535778Oneliance, LLC, Secured Debt2022-12-310001535778Oneliance, LLC, Preferred Stock2022-12-310001535778msif:OnelianceLLCMember2022-12-310001535778Orttech Holdings, LLC, Secured Debt 12022-12-310001535778Orttech Holdings, LLC, Secured Debt 22022-12-310001535778Orttech Holdings, LLC, Preferred Stock2022-12-310001535778msif:OrttechHoldingsLLCMember2022-12-310001535778Robbins Bros. Jewelry, Inc., Secured Debt 12022-12-310001535778Robbins Bros. Jewelry, Inc., Secured Debt 22022-12-310001535778Robbins Bros. Jewelry, Inc., Preferred Equity2022-12-310001535778msif:RobbinsBrosJewelryIncMember2022-12-310001535778SI East, LLC, Secured Debt 12022-12-310001535778SI East, LLC, Secured Debt 22022-12-310001535778SI East, LLC, Preferred Member Units2022-12-310001535778msif:SIEastLLCMember2022-12-310001535778Sonic Systems International, LLC, Secured Debt2022-12-310001535778Sonic Systems International, LLC, Common Stock2022-12-310001535778msif:SonicSystemsInternationalLLCMember2022-12-310001535778Student Resource Center, LLC, Secured Debt2022-12-310001535778Student Resource Center, LLC, Preferred Equity2022-12-310001535778msif:StudentResourceCenterLLCMember2022-12-310001535778Tedder Industries, LLC, Secured Debt 12022-12-310001535778Tedder Industries, LLC, Secured Debt 22022-12-310001535778Tedder Industries, LLC, Preferred Member Units2022-12-310001535778msif:TedderIndustriesLLCMember2022-12-310001535778Trantech Radiator Topco, LLC, Secured Debt 12022-12-310001535778Trantech Radiator Topco, LLC, Secured Debt 22022-12-310001535778Trantech Radiator Topco, LLC, Common Stock2022-12-310001535778msif:TrantechRadiatorTopcoLLCMember2022-12-310001535778VVS Holdco LLC, Secured Debt 12022-12-310001535778VVS Holdco LLC, Secured Debt 22022-12-310001535778VVS Holdco LLC, Preferred Equity2022-12-310001535778msif:VVSHoldcoLLCMember2022-12-310001535778AAC Holdings, Inc., Secured Debt2022-12-310001535778AAC Holdings, Inc., Common Stock2022-12-310001535778AAC Holdings, Inc., Warrants2022-12-310001535778msif:AACHoldingsIncMember2022-12-310001535778AB Centers Acquisition Corporation, Secured Debt 12022-12-310001535778AB Centers Acquisition Corporation, Secured Debt 22022-12-310001535778AB Centers Acquisition Corporation, Secured Debt 32022-12-310001535778msif:ABCentersAcquisitionCorporationMember2022-12-310001535778Acumera, Inc., Secured Debt 12022-12-310001535778Acumera, Inc., Secured Debt 22022-12-310001535778msif:AcumeraIncMember2022-12-310001535778Adams Publishing Group, LLC, Secured Debt 12022-12-310001535778Adams Publishing Group, LLC, Secured Debt 22022-12-310001535778msif:AdamsPublishingGroupLLCMember2022-12-310001535778ADS Tactical, Inc., Secured Debt2022-12-310001535778AMEREQUIP LLC., Secured Debt 12022-12-310001535778AMEREQUIP LLC., Secured Debt 22022-12-310001535778AMEREQUIP LLC., Common Stock2022-12-310001535778msif:AMEREQUIPLLCMember2022-12-310001535778American Health Staffing Group, Inc., Secured Debt 12022-12-310001535778American Health Staffing Group, Inc., Secured Debt 22022-12-310001535778msif:AmericanHealthStaffingGroupIncMember2022-12-310001535778American Nuts, LLC, Secured Debt 12022-12-310001535778American Nuts, LLC, Secured Debt 22022-12-310001535778msif:AmericanNutsLLCMember2022-12-310001535778American Teleconferencing Services, Ltd., Secured Debt 12022-12-310001535778American Teleconferencing Services, Ltd., Secured Debt 22022-12-310001535778msif:AmericanTeleconferencingServicesLtdMember2022-12-310001535778ArborWorks, LLC, Secured Debt 12022-12-310001535778ArborWorks, LLC, Secured Debt 22022-12-310001535778ArborWorks, LLC, Common Equity2022-12-310001535778msif:ArborWorksLLCMember2022-12-310001535778Archer Systems, LLC, Secured Debt 12022-12-310001535778Archer Systems, LLC, Secured Debt 22022-12-310001535778Archer Systems, LLC, Common Stock2022-12-310001535778msif:ArcherSystemsLLCMember2022-12-310001535778ATS Operating, LLC, Secured Debt 12022-12-310001535778ATS Operating, LLC, Secured Debt 22022-12-310001535778ATS Operating, LLC, Secured Debt 32022-12-310001535778ATS Operating, LLC, Common Stock2022-12-310001535778msif:ATSOperatingLLCMember2022-12-310001535778AVEX Aviation Holdings, LLC, Secured Debt 12022-12-310001535778AVEX Aviation Holdings, LLC, Secured Debt 22022-12-310001535778AVEX Aviation Holdings, LLC, Common Equity2022-12-310001535778msif:AVEXAviationHoldingsLLCMember2022-12-310001535778BBB Tank Services, LLC, Unsecured Debt 12022-12-310001535778BBB Tank Services, LLC, Unsecured Debt 22022-12-310001535778BBB Tank Services, LLC, Preferred Stock (non-voting)2022-12-310001535778BBB Tank Services, LLC, Member Units2022-12-310001535778msif:BBBTankServicesLLCMember2022-12-310001535778Berry Aviation, Inc., Secured Debt2022-12-310001535778Berry Aviation, Inc., Preferred Member Units 12022-12-310001535778Berry Aviation, Inc., Preferred Member Units 22022-12-310001535778msif:BerryAviationIncMember2022-12-310001535778Bettercloud, Inc., Secured Debt 12022-12-310001535778Bettercloud, Inc., Secured Debt 22022-12-310001535778msif:BettercloudIncMember2022-12-310001535778Binswanger Enterprises, LLC, Member Units2022-12-310001535778Bluestem Brands, Inc., Secured Debt 12022-12-310001535778Bluestem Brands, Inc., Secured Debt 22022-12-310001535778Bluestem Brands, Inc., Common Stock2022-12-310001535778Bluestem Brands, Inc., Warrants2022-12-310001535778msif:BluestemBrandsIncMember2022-12-310001535778Boccella Precast Products LLC, Secured Debt2022-12-310001535778Boccella Precast Products LLC, Member Units2022-12-310001535778msif:BoccellaPrecastProductsLLCMember2022-12-310001535778Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund III, LP)2022-12-310001535778Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund IV, LP)2022-12-310001535778msif:BrightwoodCapitalFundInvestmentsMember2022-12-310001535778Buca C, LLC, Secured Debt2022-12-310001535778Buca C, LLC, Preferred Member Units2022-12-310001535778msif:BucaCLLCMember2022-12-310001535778Burning Glass Intermediate Holding Company, Inc., Secured Debt 12022-12-310001535778Burning Glass Intermediate Holding Company, Inc., Secured Debt 22022-12-310001535778msif:BurningGlassIntermediateHoldingCompanyIncMember2022-12-310001535778Cadence Aerospace LLC, Secured Debt2022-12-310001535778CAI Software LLC, Preferred Equity 12022-12-310001535778CAI Software LLC, Preferred Equity 22022-12-310001535778msif:CAISoftwareLLCMember2022-12-310001535778Camin Cargo Control, Inc., Secured Debt2022-12-310001535778Career Team Holdings, LLC, Secured Debt 12022-12-310001535778Career Team Holdings, LLC, Secured Debt 22022-12-310001535778Career Team Holdings, LLC, Common Stock2022-12-310001535778msif:CareerTeamHoldingsLLCMember2022-12-310001535778CaseWorthy, Inc., Secured Debt 12022-12-310001535778CaseWorthy, Inc., Secured Debt 22022-12-310001535778CaseWorthy, Inc., Secured Debt 32022-12-310001535778CaseWorthy, Inc., Common Equity2022-12-310001535778msif:CaseWorthyIncMember2022-12-310001535778Channel Partners Intermediateco, LLC, Secured Debt 12022-12-310001535778Channel Partners Intermediateco, LLC, Secured Debt 22022-12-310001535778msif:ChannelPartnersIntermediatecoLLCMember2022-12-310001535778Clarius BIGS, LLC, Secured Debt2022-12-310001535778Classic H&G Holdings, LLC, Secured Debt 12022-12-310001535778Classic H&G Holdings, LLC, Secured Debt 22022-12-310001535778Classic H&G Holdings, LLC, Preferred Member Units2022-12-310001535778msif:ClassicHGHoldingsLLCMember2022-12-310001535778Computer Data Source, LLC, Secured Debt 12022-12-310001535778Computer Data Source, LLC, Secured Debt 22022-12-310001535778msif:ComputerDataSourceLLCMember2022-12-310001535778Construction Supply Investments, LLC, Member Units2022-12-310001535778Dalton US Inc., Secured Debt 12022-12-310001535778Dalton US Inc., Secured Debt 22022-12-310001535778Dalton US Inc., Secured Debt 32022-12-310001535778Dalton US Inc., Common Stock2022-12-310001535778msif:DaltonUSIncMember2022-12-310001535778DMA Industries, LLC, Secured Debt2022-12-310001535778DMA Industries, LLC, Preferred Equity2022-12-310001535778msif:DMAIndustriesLLCMember2022-12-310001535778DTE Enterprises, LLC, Secured Debt 12022-12-310001535778DTE Enterprises, LLC, Secured Debt 22022-12-310001535778DTE Enterprises, LLC, Class A Preferred Member Units2022-12-310001535778DTE Enterprises, LLC, Class AA Preferred Member Units (non-voting)2022-12-310001535778msif:DTEEnterprisesLLCMember2022-12-310001535778Dynamic Communities, LLC, Secured Debt 12022-12-310001535778Dynamic Communities, LLC, Secured Debt 22022-12-310001535778Dynamic Communities, LLC, Preferred Equity 12022-12-310001535778Dynamic Communities, LLC, Preferred Equity 22022-12-310001535778Dynamic Communities, LLC, Common Equity2022-12-310001535778msif:DynamicCommunitiesLLCMember2022-12-310001535778Elgin AcquireCo, LLC, Secured Debt 12022-12-310001535778Elgin AcquireCo, LLC, Secured Debt 22022-12-310001535778Elgin AcquireCo, LLC, Secured Debt 32022-12-310001535778Elgin AcquireCo, LLC, Common Stock 12022-12-310001535778Elgin AcquireCo, LLC, Common Stock 22022-12-310001535778msif:ElginAcquireCoLLCMember2022-12-310001535778Emerald Technologies Acquisition Co, Inc., Secured Debt2022-12-310001535778Engineering Research & Consulting, LLC, Secured Debt 12022-12-310001535778Engineering Research & Consulting, LLC, Secured Debt 22022-12-310001535778msif:EngineeringResearchConsultingLLCMember2022-12-310001535778EPIC Y-Grade Services, LP, Secured Debt2022-12-310001535778Event Holdco, LLC, Secured Debt 12022-12-310001535778Event Holdco, LLC, Secured Debt 22022-12-310001535778msif:EventHoldcoLLCMember2022-12-310001535778Flip Electronics LLC, Secured Debt 12022-12-310001535778Flip Electronics LLC, Secured Debt 22022-12-310001535778msif:FlipElectronicsLLCMember2022-12-310001535778Hawk Ridge Systems, LLC, Secured Debt 12022-12-310001535778Hawk Ridge Systems, LLC, Secured Debt 22022-12-310001535778Hawk Ridge Systems, LLC, Preferred Member Units 12022-12-310001535778Hawk Ridge Systems, LLC, Preferred Member Units 22022-12-310001535778msif:HawkRidgeSystemsLLCMember2022-12-310001535778HDC/HW Intermediate Holdings, Secured Debt 12022-12-310001535778HDC/HW Intermediate Holdings, Secured Debt 22022-12-310001535778msif:HDCHWIntermediateHoldingsMember2022-12-310001535778HEADLANDS OP-CO LLC, Secured Debt 12022-12-310001535778HEADLANDS OP-CO LLC, Secured Debt 22022-12-310001535778HEADLANDS OP-CO LLC, Secured Debt 32022-12-310001535778msif:HEADLANDSOPCOLLCMember2022-12-310001535778Hybrid Promotions, LLC, Secured Debt2022-12-310001535778IG Parent Corporation, Secured Debt 12022-12-310001535778IG Parent Corporation, Secured Debt 22022-12-310001535778msif:IGParentCorporationMember2022-12-310001535778Implus Footcare, LLC, Secured Debt2022-12-310001535778Independent Pet Partners Intermediate Holdings, LLC, Secured Debt 12022-12-310001535778Independent Pet Partners Intermediate Holdings, LLC, Secured Debt 22022-12-310001535778Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) 12022-12-310001535778Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) 22022-12-310001535778Independent Pet Partners Intermediate Holdings, LLC, Member Units2022-12-310001535778Independent Pet Partners Intermediate Holdings, LLC, Warrants2022-12-310001535778msif:IndependentPetPartnersIntermediateHoldingsLLCMember2022-12-310001535778Industrial Services Acquisition, LLC, Secured Debt 12022-12-310001535778Industrial Services Acquisition, LLC, Secured Debt 22022-12-310001535778Industrial Services Acquisition, LLC, Preferred Member Units 12022-12-310001535778Industrial Services Acquisition, LLC, Preferred Member Units 22022-12-310001535778Industrial Services Acquisition, LLC, Member Units2022-12-310001535778msif:IndustrialServicesAcquisitionLLCMember2022-12-310001535778Infolinks Media Buyco, LLC, Secured Debt 12022-12-310001535778Infolinks Media Buyco, LLC, Secured Debt 22022-12-310001535778msif:InfolinksMediaBuycoLLCMember2022-12-310001535778Interface Security Systems, L.L.C, Secured Debt 12022-12-310001535778Interface Security Systems, L.L.C, Secured Debt 22022-12-310001535778Interface Security Systems, L.L.C, Common Stock2022-12-310001535778msif:InterfaceSecuritySystemsLLCMember2022-12-310001535778Intermedia Holdings, Inc., Secured Debt2022-12-310001535778Invincible Boat Company, LLC., Secured Debt 12022-12-310001535778Invincible Boat Company, LLC., Secured Debt 22022-12-310001535778msif:InvincibleBoatCompanyLLCMember2022-12-310001535778INW Manufacturing, LLC, Secured Debt2022-12-310001535778Iron-Main Investments, LLC, Secured Debt 12022-12-310001535778Iron-Main Investments, LLC, Secured Debt 22022-12-310001535778Iron-Main Investments, LLC, Secured Debt 32022-12-310001535778Iron-Main Investments, LLC, Secured Debt 42022-12-310001535778Iron-Main Investments, LLC, Common Stock2022-12-310001535778msif:IronMainInvestmentsLLCMember2022-12-310001535778Isagenix International, LLC, Secured Debt2022-12-310001535778Jackmont Hospitality, Inc., Secured Debt 12022-12-310001535778Jackmont Hospitality, Inc., Secured Debt 22022-12-310001535778Jackmont Hospitality, Inc., Preferred Equity2022-12-310001535778msif:JackmontHospitalityIncMember2022-12-310001535778Joerns Healthcare, LLC, Secured Debt 12022-12-310001535778Joerns Healthcare, LLC, Secured Debt 22022-12-310001535778Joerns Healthcare, LLC, Common Stock2022-12-310001535778msif:JoernsHealthcareLLCMember2022-12-310001535778Johnson Downie Opco, LLC, Secured Debt 12022-12-310001535778Johnson Downie Opco, LLC, Secured Debt 22022-12-310001535778Johnson Downie Opco, LLC, Preferred Equity2022-12-310001535778msif:JohnsonDownieOpcoLLCMember2022-12-310001535778JorVet Holdings, LLC, Secured Debt2022-12-310001535778JorVet Holdings, LLC, Preferred Equity2022-12-310001535778msif:JorVetHoldingsLLCMember2022-12-310001535778JTI Electrical & Mechanical, LLC, Secured Debt 12022-12-310001535778JTI Electrical & Mechanical, LLC, Secured Debt 22022-12-310001535778JTI Electrical & Mechanical, LLC, Common Equity2022-12-310001535778msif:JTIElectricalMechanicalLLCMember2022-12-310001535778KMS, LLC, Secured Debt 12022-12-310001535778KMS, LLC, Secured Debt 22022-12-310001535778msif:KMSLLCMember2022-12-310001535778Lightbox Holdings, L.P., Secured Debt2022-12-310001535778LL Management, Inc., Secured Debt 12022-12-310001535778LL Management, Inc., Secured Debt 22022-12-310001535778LL Management, Inc., Secured Debt 32022-12-310001535778msif:LLManagementIncMember2022-12-310001535778LLFlex, LLC, Secured Debt2022-12-310001535778Logix Acquisition Company, LLC, Secured Debt2022-12-310001535778Mako Steel, LP, Secured Debt 12022-12-310001535778Mako Steel, LP, Secured Debt 22022-12-310001535778msif:MakoSteelLPMember2022-12-310001535778MB2 Dental Solutions, LLC, Secured Debt 12022-12-310001535778MB2 Dental Solutions, LLC, Secured Debt 22022-12-310001535778msif:MB2DentalSolutionsLLCMember2022-12-310001535778MetalForming AcquireCo, LLC, Secured Debt 12022-12-310001535778MetalForming AcquireCo, LLC, Secured Debt 22022-12-310001535778MetalForming AcquireCo, LLC, Preferred Equity2022-12-310001535778MetalForming AcquireCo, LLC, Common Stock2022-12-310001535778msif:MetalFormingAcquireCoLLCMember2022-12-310001535778Microbe Formulas, LLC, Secured Debt 12022-12-310001535778Microbe Formulas, LLC, Secured Debt 22022-12-310001535778msif:MicrobeFormulasLLCMember2022-12-310001535778Mills Fleet Farm Group, LLC, Secured Debt2022-12-310001535778MonitorUS Holding, LLC, Secured Debt 12022-12-310001535778MonitorUS Holding, LLC, Secured Debt 22022-12-310001535778MonitorUS Holding, LLC, Secured Debt 32022-12-310001535778MonitorUS Holding, LLC, Common Stock2022-12-310001535778msif:MonitorUSHoldingLLCMember2022-12-310001535778NinjaTrader, LLC, Secured Debt 12022-12-310001535778NinjaTrader, LLC, Secured Debt 22022-12-310001535778NinjaTrader, LLC, Secured Debt 32022-12-310001535778msif:NinjaTraderLLCMember2022-12-310001535778NTM Acquisition Corp., Secured Debt2022-12-310001535778NWN Corporation, Secured Debt 12022-12-310001535778NWN Corporation, Secured Debt 22022-12-310001535778NWN Corporation, Secured Debt 32022-12-310001535778msif:NWNCorporationMember2022-12-310001535778OVG Business Services, LLC, Secured Debt2022-12-310001535778Paragon Healthcare, Inc., Secured Debt 12022-12-310001535778Paragon Healthcare, Inc., Secured Debt 22022-12-310001535778Paragon Healthcare, Inc., Secured Debt 32022-12-310001535778msif:ParagonHealthcareIncMember2022-12-310001535778PTL US Bidco, Inc, Secured Debt 12022-12-310001535778PTL US Bidco, Inc, Secured Debt 22022-12-310001535778msif:PTLUSBidcoIncMember2022-12-310001535778RA Outdoors LLC, Secured Debt 32022-12-310001535778RA Outdoors LLC, Secured Debt 42022-12-310001535778msif:RAOutdoorsLLCMember2022-12-310001535778Research Now Group, Inc. and Survey Sampling International, LLC, Secured Debt 22022-12-310001535778RM Bidder, LLC, Member Units2022-12-310001535778RM Bidder, LLC, Warrants2022-12-310001535778msif:RMBidderLLCMember2022-12-310001535778Roof Opco, LLC, Secured Debt 12022-12-310001535778Roof Opco, LLC, Secured Debt 22022-12-310001535778Roof Opco, LLC, Secured Debt 32022-12-310001535778msif:RoofOpcoLLCMember2022-12-310001535778Rug Doctor, LLC., Secured Debt 12022-12-310001535778Rug Doctor, LLC., Secured Debt 22022-12-310001535778msif:RugDoctorLLCMember2022-12-310001535778Savers, Inc., Secured Debt2022-12-310001535778SIB Holdings, LLC, Secured Debt 12022-12-310001535778SIB Holdings, LLC, Secured Debt 22022-12-310001535778SIB Holdings, LLC, Secured Debt 32022-12-310001535778SIB Holdings, LLC, Common Equity2022-12-310001535778msif:SIBHoldingsLLCMember2022-12-310001535778Slick Innovations, LLC, Secured Debt2022-12-310001535778Slick Innovations, LLC, Common Stock2022-12-310001535778msif:SlickInnovationsLLCMember2022-12-310001535778South Coast Terminals Holdings, LLC, Secured Debt 12022-12-310001535778South Coast Terminals Holdings, LLC, Secured Debt 22022-12-310001535778South Coast Terminals Holdings, LLC, Common Equity2022-12-310001535778msif:SouthCoastTerminalsHoldingsLLCMember2022-12-310001535778SPAU Holdings, LLC, Secured Debt 12022-12-310001535778SPAU Holdings, LLC, Secured Debt 22022-12-310001535778SPAU Holdings, LLC, Common Stock2022-12-310001535778msif:SPAUHoldingsLLCMember2022-12-310001535778Tex Tech Tennis, LLC, Preferred Equity2022-12-310001535778The Affiliati Network, LLC, Secured Debt 12022-12-310001535778The Affiliati Network, LLC, Secured Debt 22022-12-310001535778The Affiliati Network, LLC, Preferred Stock2022-12-310001535778msif:TheAffiliatiNetworkLLCMember2022-12-310001535778U.S. TelePacific Corp., Secured Debt2022-12-310001535778USA DeBusk LLC, Secured Debt2022-12-310001535778Vida Capital, Inc, Secured Debt2022-12-310001535778Vistar Media, Inc., Preferred Stock2022-12-310001535778Volusion, LLC, Secured Debt2022-12-310001535778Volusion, LLC, Unsecured Convertible Debt2022-12-310001535778Volusion, LLC, Preferred Member Units2022-12-310001535778Volusion, LLC, Warrants2022-12-310001535778msif:VolusionLLCMember2022-12-310001535778VORTEQ Coil Finishers, LLC, Common Equity2022-12-310001535778Wall Street Prep, Inc., Secured Debt 12022-12-310001535778Wall Street Prep, Inc., Secured Debt 22022-12-310001535778Wall Street Prep, Inc., Common Stock2022-12-310001535778msif:WallStreetPrepIncMember2022-12-310001535778Watterson Brands, LLC, Secured Debt 12022-12-310001535778Watterson Brands, LLC, Secured Debt 22022-12-310001535778Watterson Brands, LLC, Secured Debt 32022-12-310001535778msif:WattersonBrandsLLCMember2022-12-310001535778West Star Aviation Acquisition, LLC, Secured Debt 12022-12-310001535778West Star Aviation Acquisition, LLC, Secured Debt 22022-12-310001535778West Star Aviation Acquisition, LLC, Common Stock2022-12-310001535778msif:WestStarAviationAcquisitionLLCMember2022-12-310001535778Winter Services LLC, Secured Debt 12022-12-310001535778Winter Services LLC, Secured Debt 22022-12-310001535778Winter Services LLC, Secured Debt 32022-12-310001535778msif:WinterServicesLLCMember2022-12-310001535778World Micro Holdings, LLC, Secured Debt2022-12-310001535778World Micro Holdings, LLC, Preferred Equity2022-12-310001535778msif:WorldMicroHoldingsLLCMember2022-12-310001535778Xenon Arc, Inc., Secured Debt 12022-12-310001535778Xenon Arc, Inc., Secured Debt 22022-12-310001535778Xenon Arc, Inc., Secured Debt 32022-12-310001535778msif:XenonArcIncMember2022-12-310001535778YS Garments, LLC, Secured Debt2022-12-310001535778Zips Car Wash, LLC, Secured Debt 12022-12-310001535778Zips Car Wash, LLC, Secured Debt 22022-12-310001535778msif:ZipsCarWashLLCMember2022-12-310001535778US Bank Money Market Account2022-12-310001535778us-gaap:ShortTermInvestmentsMember2022-12-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembersrt:MinimumMember2022-12-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembersrt:MaximumMember2022-12-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembersrt:WeightedAverageMember2022-12-310001535778srt:MinimumMember2022-12-310001535778srt:MaximumMember2022-12-310001535778RM Bidder, LLC, Warrants2022-01-012022-12-3100015357782022-01-012022-12-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ParagonHealthcareIncMember2022-12-310001535778msif:CadenceAerospaceLLCMember2022-12-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembermsif:CadenceAerospaceLLCMember2022-12-310001535778msif:MakoSteelLPMemberus-gaap:LondonInterbankOfferedRateLIBORMember2022-12-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ZipsCarWashLLCMember2022-12-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ChannelPartnersIntermediatecoLLCMember2022-12-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:ChannelPartnersIntermediatecoLLC2Member2022-12-310001535778msif:ChannelPartnersIntermediatecoLLC2Member2022-12-310001535778msif:ComputerDataSourceLLCMemberus-gaap:LondonInterbankOfferedRateLIBORMember2022-12-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:IGParentCorporationMember2022-12-310001535778us-gaap:LondonInterbankOfferedRateLIBORMembermsif:InterfaceSecuritySystemsLLCMember2022-12-310001535778msif:SecuredOvernightFinancingRateSOFRMembermsif:NWNCorporationMember2022-12-310001535778msif:PrivateLoanPortfolioMember2023-01-012023-03-310001535778msif:PrivateLoanPortfolioMember2023-03-31msif:company0001535778msif:InvestmentOwnedAtFairValueMembermsif:PrivateLoanPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:PrivateLoanPortfolioMember2022-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:PrivateLoanPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-03-310001535778msif:PrivateLoanPortfolioMember2022-01-012022-03-310001535778msif:LowerMiddleMarketPortfolioMember2023-01-012023-03-310001535778msif:LowerMiddleMarketPortfolioMember2023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:LowerMiddleMarketPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:LowerMiddleMarketPortfolioMember2022-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:LowerMiddleMarketPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-03-310001535778msif:LowerMiddleMarketPortfolioMember2022-01-012022-03-310001535778msif:MiddleMarketPortfolioMember2023-03-310001535778msif:MiddleMarketPortfolioMember2022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2022-01-012022-12-310001535778us-gaap:NonperformingFinancingReceivableMember2023-03-31msif:investment0001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:NonperformingFinancingReceivableMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:NonperformingFinancingReceivableMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778us-gaap:NonperformingFinancingReceivableMember2022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:NonperformingFinancingReceivableMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:NonperformingFinancingReceivableMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:EquitySecuritiesMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMembersrt:MinimumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMembersrt:MaximumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMembermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMembersrt:MedianMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMemberus-gaap:EquitySecuritiesMembersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMemberus-gaap:EquitySecuritiesMembersrt:MaximumMemberus-gaap:MeasurementInputEbitdaMultipleMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMembersrt:WeightedAverageMemberus-gaap:EquitySecuritiesMemberus-gaap:MeasurementInputEbitdaMultipleMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMemberus-gaap:EquitySecuritiesMembersrt:MedianMemberus-gaap:MeasurementInputEbitdaMultipleMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputRiskAdjustedDiscountFactorMembersrt:MinimumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputRiskAdjustedDiscountFactorMembersrt:MaximumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:WeightedAverageMembermsif:MeasurementInputRiskAdjustedDiscountFactorMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputRiskAdjustedDiscountFactorMembersrt:MedianMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMembersrt:MinimumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMembersrt:MaximumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:WeightedAverageMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:MedianMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMember2023-03-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMemberus-gaap:MarketApproachValuationTechniqueMember2023-03-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMemberus-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMembermsif:MeasurementInputThirdPartyQuoteMember2023-03-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMemberus-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMembermsif:MeasurementInputThirdPartyQuoteMember2023-03-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:MarketApproachValuationTechniqueMembermsif:MeasurementInputThirdPartyQuoteMember2023-03-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:MedianMemberus-gaap:MarketApproachValuationTechniqueMembermsif:MeasurementInputThirdPartyQuoteMember2023-03-310001535778us-gaap:FairValueInputsLevel3Member2023-03-310001535778us-gaap:FairValueInputsLevel3Membersrt:MinimumMembermsif:MeasurementInputEBITDAMultipleOutlierMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membersrt:MaximumMembermsif:MeasurementInputEBITDAMultipleOutlierMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:MeasurementInputRiskAdjustedDiscountFactorOutlierMembersrt:MinimumMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:MeasurementInputRiskAdjustedDiscountFactorOutlierMembersrt:MaximumMember2023-03-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:EquitySecuritiesMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMembersrt:MinimumMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMembersrt:MaximumMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMembermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membermsif:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:EquitySecuritiesMembersrt:MedianMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMemberus-gaap:EquitySecuritiesMembersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMemberus-gaap:EquitySecuritiesMembersrt:MaximumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMembersrt:WeightedAverageMemberus-gaap:EquitySecuritiesMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:ValuationMarketAndEnterpriseValueApproachMemberus-gaap:EquitySecuritiesMembersrt:MedianMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputRiskAdjustedDiscountFactorMembersrt:MinimumMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputRiskAdjustedDiscountFactorMembersrt:MaximumMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:WeightedAverageMembermsif:MeasurementInputRiskAdjustedDiscountFactorMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputRiskAdjustedDiscountFactorMembersrt:MedianMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMembersrt:MinimumMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMembersrt:MaximumMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:WeightedAverageMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMember2022-12-310001535778us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:MedianMembermsif:MeasurementInputExpectedPrincipalRecoveryPercentageMember2022-12-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMemberus-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMembermsif:MeasurementInputThirdPartyQuoteMember2022-12-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMemberus-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMembermsif:MeasurementInputThirdPartyQuoteMember2022-12-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:MarketApproachValuationTechniqueMembermsif:MeasurementInputThirdPartyQuoteMember2022-12-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMembersrt:MedianMemberus-gaap:MarketApproachValuationTechniqueMembermsif:MeasurementInputThirdPartyQuoteMember2022-12-310001535778us-gaap:FairValueInputsLevel3Member2022-12-310001535778us-gaap:FairValueInputsLevel3Membersrt:MinimumMembermsif:MeasurementInputEBITDAMultipleOutlierMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membersrt:MaximumMembermsif:MeasurementInputEBITDAMultipleOutlierMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:MeasurementInputRiskAdjustedDiscountFactorOutlierMembersrt:MinimumMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:MeasurementInputRiskAdjustedDiscountFactorOutlierMembersrt:MaximumMember2022-12-310001535778us-gaap:DebtSecuritiesMember2022-12-310001535778us-gaap:DebtSecuritiesMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMembermsif:DebtAndEquitySecuritiesRealizedGainLossMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:DebtSecuritiesMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMember2023-03-310001535778us-gaap:EquitySecuritiesMember2022-12-310001535778us-gaap:EquitySecuritiesMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:EquitySecuritiesMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:EquitySecuritiesMember2023-01-012023-03-310001535778us-gaap:EquitySecuritiesMember2023-03-310001535778msif:EquityWarrantMember2022-12-310001535778msif:EquityWarrantMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesRealizedGainLossMembermsif:EquityWarrantMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMembermsif:EquityWarrantMember2023-01-012023-03-310001535778msif:EquityWarrantMember2023-03-310001535778us-gaap:InvestmentsMember2022-12-310001535778us-gaap:InvestmentsMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:InvestmentsMember2023-01-012023-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:InvestmentsMember2023-01-012023-03-310001535778us-gaap:InvestmentsMember2023-03-310001535778us-gaap:DebtSecuritiesMember2021-12-310001535778us-gaap:DebtSecuritiesMember2022-01-012022-03-310001535778us-gaap:DebtSecuritiesMembermsif:DebtAndEquitySecuritiesRealizedGainLossMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:DebtSecuritiesMember2022-01-012022-03-310001535778us-gaap:DebtSecuritiesMember2022-03-310001535778us-gaap:EquitySecuritiesMember2021-12-310001535778us-gaap:EquitySecuritiesMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:EquitySecuritiesMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:EquitySecuritiesMember2022-01-012022-03-310001535778us-gaap:EquitySecuritiesMember2022-03-310001535778msif:EquityWarrantMember2021-12-310001535778msif:EquityWarrantMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesRealizedGainLossMembermsif:EquityWarrantMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMembermsif:EquityWarrantMember2022-01-012022-03-310001535778msif:EquityWarrantMember2022-03-310001535778us-gaap:InvestmentsMember2021-12-310001535778us-gaap:InvestmentsMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:InvestmentsMember2022-01-012022-03-310001535778msif:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:InvestmentsMember2022-01-012022-03-310001535778us-gaap:InvestmentsMember2022-03-310001535778msif:PrivateLoanPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel1Membermsif:PrivateLoanPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel2Membermsif:PrivateLoanPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:PrivateLoanPortfolioMember2023-03-310001535778msif:LowerMiddleMarketPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel1Membermsif:LowerMiddleMarketPortfolioMember2023-03-310001535778msif:LowerMiddleMarketPortfolioMemberus-gaap:FairValueInputsLevel2Member2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:LowerMiddleMarketPortfolioMember2023-03-310001535778msif:MiddleMarketPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel1Membermsif:MiddleMarketPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel2Membermsif:MiddleMarketPortfolioMember2023-03-310001535778us-gaap:FairValueInputsLevel3Membermsif:MiddleMarketPortfolioMember2023-03-310001535778us-gaap:OtherAggregatedInvestmentsMember2023-03-310001535778us-gaap:FairValueInputsLevel1Memberus-gaap:OtherAggregatedInvestmentsMember2023-03-310001535778us-gaap:FairValueInputsLevel2Memberus-gaap:OtherAggregatedInvestmentsMember2023-03-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:OtherAggregatedInvestmentsMember2023-03-310001535778us-gaap:FairValueInputsLevel1Member2023-03-310001535778us-gaap:FairValueInputsLevel2Member2023-03-310001535778msif:PrivateLoanPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel1Membermsif:PrivateLoanPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel2Membermsif:PrivateLoanPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:PrivateLoanPortfolioMember2022-12-310001535778msif:LowerMiddleMarketPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel1Membermsif:LowerMiddleMarketPortfolioMember2022-12-310001535778msif:LowerMiddleMarketPortfolioMemberus-gaap:FairValueInputsLevel2Member2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:LowerMiddleMarketPortfolioMember2022-12-310001535778msif:MiddleMarketPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel1Membermsif:MiddleMarketPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel2Membermsif:MiddleMarketPortfolioMember2022-12-310001535778us-gaap:FairValueInputsLevel3Membermsif:MiddleMarketPortfolioMember2022-12-310001535778us-gaap:OtherAggregatedInvestmentsMember2022-12-310001535778us-gaap:FairValueInputsLevel1Memberus-gaap:OtherAggregatedInvestmentsMember2022-12-310001535778us-gaap:FairValueInputsLevel2Memberus-gaap:OtherAggregatedInvestmentsMember2022-12-310001535778us-gaap:FairValueInputsLevel3Memberus-gaap:OtherAggregatedInvestmentsMember2022-12-310001535778us-gaap:FairValueInputsLevel1Member2022-12-310001535778us-gaap:FairValueInputsLevel2Member2022-12-310001535778msif:PrivateLoanPortfolioMembersrt:MinimumMember2023-03-310001535778msif:PrivateLoanPortfolioMembersrt:MaximumMember2023-03-310001535778us-gaap:DebtSecuritiesMembermsif:PrivateLoanPortfolioMembersrt:MinimumMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMembermsif:PrivateLoanPortfolioMembersrt:MaximumMember2023-01-012023-03-310001535778msif:LowerMiddleMarketPortfolioMembersrt:MinimumMember2023-01-012023-03-310001535778msif:LowerMiddleMarketPortfolioMembersrt:MaximumMember2023-01-012023-03-310001535778msif:LowerMiddleMarketPortfolioMembersrt:MinimumMember2023-03-310001535778msif:LowerMiddleMarketPortfolioMembersrt:MaximumMember2023-03-310001535778us-gaap:DebtSecuritiesMembermsif:LowerMiddleMarketPortfolioMembersrt:MinimumMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMembermsif:LowerMiddleMarketPortfolioMembersrt:MaximumMember2023-01-012023-03-310001535778msif:MiddleMarketPortfolioMembersrt:MinimumMember2023-01-012023-03-310001535778msif:MiddleMarketPortfolioMembersrt:MaximumMember2023-01-012023-03-310001535778msif:MiddleMarketPortfolioMembersrt:MinimumMember2023-03-310001535778msif:MiddleMarketPortfolioMembersrt:MaximumMember2023-03-310001535778us-gaap:DebtSecuritiesMembermsif:MiddleMarketPortfolioMembersrt:MinimumMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMembermsif:MiddleMarketPortfolioMembersrt:MaximumMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMembersrt:MinimumMemberus-gaap:OtherAggregatedInvestmentsMember2023-01-012023-03-310001535778us-gaap:DebtSecuritiesMembersrt:MaximumMemberus-gaap:OtherAggregatedInvestmentsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMembermsif:PrivateLoanPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMembermsif:LowerMiddleMarketPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMembermsif:MiddleMarketPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:PrivateLoanPortfolioMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:LowerMiddleMarketPortfolioMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:MiddleMarketPortfolioMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:PrivateLoanPortfolioMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:LowerMiddleMarketPortfolioMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:MiddleMarketPortfolioMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778us-gaap:NonperformingFinancingReceivableMembermsif:PrivateLoanPortfolioMember2023-03-310001535778msif:LowerMiddleMarketPortfolioMemberus-gaap:NonperformingFinancingReceivableMember2023-03-310001535778us-gaap:NonperformingFinancingReceivableMembermsif:MiddleMarketPortfolioMember2023-03-310001535778msif:PrivateLoanPortfolioMember2022-12-310001535778msif:LowerMiddleMarketPortfolioMember2022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMembermsif:PrivateLoanPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMembermsif:LowerMiddleMarketPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMembermsif:MiddleMarketPortfolioMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:PrivateLoanPortfolioMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:LowerMiddleMarketPortfolioMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:MiddleMarketPortfolioMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:PrivateLoanPortfolioMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:LowerMiddleMarketPortfolioMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:MiddleMarketPortfolioMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778us-gaap:NonperformingFinancingReceivableMembermsif:PrivateLoanPortfolioMember2022-12-310001535778msif:LowerMiddleMarketPortfolioMemberus-gaap:NonperformingFinancingReceivableMember2022-12-310001535778us-gaap:NonperformingFinancingReceivableMembermsif:MiddleMarketPortfolioMember2022-12-310001535778msif:PrivateLoanPortfolioMember2022-01-012022-12-310001535778us-gaap:OtherAggregatedInvestmentsMember2023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2023-01-012023-03-310001535778us-gaap:OtherAggregatedInvestmentsMember2022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:DebtSecuritiesSecondLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:DebtSecuritiesSecondLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:EquityWarrantMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:EquityWarrantMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:DebtSecuritiesFirstLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:EquitySecuritiesMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:DebtSecuritiesSecondLienMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:DebtSecuritiesSecondLienMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:EquityWarrantMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:EquityWarrantMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:InvestmentTypeConcentrationRiskMemberus-gaap:OtherAggregatedInvestmentsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:InvestmentTypeConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:InvestmentTypeConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap-supplement:WestRegionMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap-supplement:WestRegionMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778us-gaap-supplement:SouthwestRegionMembermsif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778us-gaap-supplement:SouthwestRegionMembermsif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap-supplement:NortheastRegionMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap-supplement:NortheastRegionMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMemberus-gaap-supplement:SoutheastRegionMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMemberus-gaap-supplement:SoutheastRegionMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap-supplement:MidwestRegionMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap-supplement:MidwestRegionMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMembercountry:CA2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMembercountry:CA2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMemberus-gaap:NonUsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMemberus-gaap:NonUsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778us-gaap-supplement:SouthwestRegionMembermsif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778us-gaap-supplement:SouthwestRegionMembermsif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap-supplement:WestRegionMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap-supplement:WestRegionMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap-supplement:NortheastRegionMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap-supplement:NortheastRegionMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap-supplement:MidwestRegionMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap-supplement:MidwestRegionMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMemberus-gaap-supplement:SoutheastRegionMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMemberus-gaap-supplement:SoutheastRegionMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMembercountry:CA2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMembercountry:CA2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMemberus-gaap:NonUsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMemberus-gaap:NonUsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMemberus-gaap:GeographicConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:CommercialServicesSuppliesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:CommercialServicesSuppliesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:InternetSoftwareServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:InternetSoftwareServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:MachineryMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:MachineryMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ITServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ITServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:HealthCareProvidersServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:HealthCareProvidersServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DistributorsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DistributorsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedConsumerServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedConsumerServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:SpecialtyRetailMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:SpecialtyRetailMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ProfessionalServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ProfessionalServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:LeisureEquipmentProductsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:LeisureEquipmentProductsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:AerospaceDefenseMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:AerospaceDefenseMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:CommunicationsEquipmentMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:CommunicationsEquipmentMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ContainersPackagingMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ContainersPackagingMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedTelecommunicationServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedTelecommunicationServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ConstructionEngineeringMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ConstructionEngineeringMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:MediaMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:MediaMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:BuildingProductsMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:BuildingProductsMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:HotelsRestaurantsLeisureMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:HotelsRestaurantsLeisureMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:HouseholdProductsMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:HouseholdProductsMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:TextilesApparelLuxuryGoodsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:TextilesApparelLuxuryGoodsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ComputersPeripheralsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ComputersPeripheralsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ElectricalEquipmentMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:ElectricalEquipmentMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedFinancialServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedFinancialServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:InternetCatalogRetailMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:InternetCatalogRetailMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:SoftwareMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:SoftwareMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:HealthCareEquipmentSuppliesMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:HealthCareEquipmentSuppliesMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:EnergyEquipmentServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:EnergyEquipmentServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:FoodProductsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:FoodProductsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:OtherMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMembermsif:OtherMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtCostMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:CommercialServicesSuppliesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:CommercialServicesSuppliesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:MachineryMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:MachineryMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:InternetSoftwareServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:InternetSoftwareServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedConsumerServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedConsumerServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DistributorsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DistributorsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ITServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ITServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:HealthCareProvidersServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:HealthCareProvidersServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ContainersPackagingMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ContainersPackagingMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:LeisureEquipmentProductsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:LeisureEquipmentProductsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:AerospaceDefenseMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:AerospaceDefenseMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:SpecialtyRetailMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:SpecialtyRetailMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ConstructionEngineeringMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ConstructionEngineeringMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ComputersPeripheralsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ComputersPeripheralsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ProfessionalServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ProfessionalServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:MediaMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:MediaMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedTelecommunicationServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedTelecommunicationServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:BuildingProductsMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:BuildingProductsMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ConstructionMaterialsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ConstructionMaterialsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ElectricalEquipmentMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:ElectricalEquipmentMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:HouseholdProductsMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:HouseholdProductsMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:TextilesApparelLuxuryGoodsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:TextilesApparelLuxuryGoodsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:InternetCatalogRetailMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:InternetCatalogRetailMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedFinancialServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:DiversifiedFinancialServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:SoftwareMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:SoftwareMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:HotelsRestaurantsLeisureMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:HotelsRestaurantsLeisureMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:AirFreightLogisticsMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:AirFreightLogisticsMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:CommunicationsEquipmentMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:CommunicationsEquipmentMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:EnergyEquipmentServicesMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:EnergyEquipmentServicesMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:OtherMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMembermsif:OtherMember2022-01-012022-12-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMember2023-01-012023-03-310001535778msif:InvestmentOwnedAtFairValueMembermsif:IndustryConcentrationRiskMember2022-01-012022-12-310001535778us-gaap:RevolvingCreditFacilityMembermsif:JPMSPVFacilityMemberus-gaap:LineOfCreditMember2023-03-310001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2023-03-310001535778us-gaap:RevolvingCreditFacilityMembermsif:JPMSPVFacilityMemberus-gaap:LineOfCreditMember2022-12-310001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2022-12-310001535778us-gaap:RevolvingCreditFacilityMembermsif:JPMSPVFacilityMemberus-gaap:LineOfCreditMember2023-01-012023-03-310001535778us-gaap:RevolvingCreditFacilityMembermsif:JPMSPVFacilityMemberus-gaap:LineOfCreditMember2022-01-012022-03-310001535778msif:SeriesANotesDue2026Memberus-gaap:UnsecuredDebtMember2023-01-012023-03-310001535778msif:SeriesANotesDue2026Memberus-gaap:UnsecuredDebtMember2022-01-012022-03-310001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2023-01-012023-03-310001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2022-01-012022-03-31msif:extensionOption0001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMembermsif:DebtVariableRateComponentOneMember2017-03-062017-03-060001535778us-gaap:RevolvingCreditFacilityMembermsif:DebtVariableRateComponentTwoMemberus-gaap:BaseRateMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2017-03-062017-03-060001535778us-gaap:RevolvingCreditFacilityMembermsif:FederalFundsRateMembermsif:DebtVariableRateComponentTwoMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2017-03-062017-03-060001535778us-gaap:RevolvingCreditFacilityMembermsif:DebtVariableRateComponentTwoMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2017-03-062017-03-060001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMembersrt:MinimumMembermsif:TIAACreditFacilityMember2017-03-062017-03-060001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LineOfCreditMembersrt:MaximumMembermsif:TIAACreditFacilityMember2017-03-062017-03-060001535778msif:SecuredOvernightFinancingRateSOFRMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:SubsequentEventMemberus-gaap:LineOfCreditMembermsif:TIAACreditFacilityMember2023-04-272023-04-270001535778us-gaap:RevolvingCreditFacilityMemberus-gaap:LondonInterbankOfferedRateLIBORMembermsif:JPMSPVFacilityMemberus-gaap:LineOfCreditMember2021-02-032021-02-030001535778us-gaap:RevolvingCreditFacilityMembermsif:JPMSPVFacilityMemberus-gaap:LineOfCreditMember2021-02-032021-02-030001535778msif:SeriesANotesDue2026Memberus-gaap:UnsecuredDebtMember2021-10-210001535778msif:SeriesANotesDue2026Memberus-gaap:UnsecuredDebtMember2022-01-210001535778Brightwood Capital Fund III, LP2023-03-310001535778Freeport First Lien Loan Fund III LP2023-03-310001535778HPEP 3, L.P.2023-03-310001535778us-gaap:EquitySecuritiesMember2023-03-310001535778Winter Services LLC2023-03-310001535778Infolinks Media Buyco, LLC2023-03-310001535778NinjaTrader, LLC2023-03-310001535778HEADLANDS OP-CO LLC2023-03-310001535778SI East, LLC2023-03-310001535778Bluestem Brands, Inc.2023-03-310001535778Mako Steel, LP2023-03-310001535778MB2 Dental Solutions, LLC2023-03-310001535778Roof Opco, LLC2023-03-310001535778American Health Staffing Group, Inc.2023-03-310001535778IG Parent Corporation2023-03-310001535778KMS, LLC2023-03-310001535778ArborWorks, LLC2023-03-310001535778Dalton US Inc.2023-03-310001535778Bettercloud, Inc.2023-03-310001535778GRT Rubber Technologies LLC2023-03-310001535778Burning Glass Intermediate Holding Company, Inc.2023-03-310001535778SPAU Holdings, LLC2023-03-310001535778NWN Corporation2023-03-310001535778RA Outdoors LLC2023-03-310001535778Classic H&G Holdco, LLC2023-03-310001535778CaseWorthy, Inc.2023-03-310001535778VVS Holdco, LLC2023-03-310001535778Jackmont Hospitality, Inc.2023-03-310001535778DTE Enterprises, LLC2023-03-310001535778Direct Marketing Solutions, Inc.2023-03-310001535778Evergreen North America Acquisitions, LLC2023-03-310001535778JTI Electrical & Mechanical, LLC2023-03-310001535778West Star Aviation Acquisition, LLC2023-03-310001535778Centre Technologies Holdings, LLC2023-03-310001535778Xenon Arc, Inc.2023-03-310001535778PTL US Bidco, Inc2023-03-310001535778Engineering Research & Consulting, LLC2023-03-310001535778Robbins Bros. Jewelry, Inc.2023-03-310001535778Wall Street Prep, Inc.2023-03-310001535778The Affiliati Network, LLC2023-03-310001535778Watterson Brands, LLC2023-03-310001535778MonitorUS Holding, LLC2023-03-310001535778Microbe Formulas, LLC2023-03-310001535778Paragon Healthcare, Inc.2023-03-310001535778Trantech Radiator Topco, LLC2023-03-310001535778Chamberlin Holding LLC2023-03-310001535778Colonial Electric Company LLC2023-03-310001535778Channel Partners Intermediateco, LLC2023-03-310001535778AMEREQUIP LLC.2023-03-310001535778South Coast Terminals Holdings, LLC2023-03-310001535778Cody Pools, Inc.2023-03-310001535778Invincible Boat Company, LLC.2023-03-310001535778Batjer TopCo, LLC2023-03-310001535778Gamber-Johnson Holdings, LLC2023-03-310001535778Archer Systems, LLC2023-03-310001535778AVEX Aviation Holdings, LLC2023-03-310001535778MetalForming AcquireCo, LLC2023-03-310001535778ATS Operating, LLC2023-03-310001535778Mystic Logistics Holdings, LLC2023-03-310001535778Johnson Downie Opco, LLC2023-03-310001535778Orttech Holdings, LLC2023-03-310001535778Career Team Holdings, LLC2023-03-310001535778AB Centers Acquisition Corporation2023-03-310001535778Elgin AcquireCo, LLC2023-03-310001535778Gulf Publishing Holdings, LLC2023-03-310001535778Flame King Holdings, LLC2023-03-310001535778Clad-Rex Steel, LLC2023-03-310001535778AAC Holdings, Inc.2023-03-310001535778Adams Publishing Group, LLC2023-03-310001535778Acumera, Inc.2023-03-310001535778Interface Security Systems, L.L.C2023-03-310001535778us-gaap:DebtSecuritiesMember2023-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:MSCIncomeMembermsif:AdvisoryAgreementMembersrt:AffiliatedEntityMember2021-10-30msif:component0001535778msif:MSCIncomeMembersrt:AffiliatedEntityMembermsif:AdvisoryAgreementIncentiveRatePreIncentiveFeeNetInvestmentIncomeMember2020-10-302020-10-300001535778msif:AdvisoryAgreementIncentiveRateQuarterlyHurdleRateMembermsif:MSCIncomeMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:MSCIncomeMembermsif:AdvisoryAgreementIncentiveRateAnnualizedHurdleRateMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:MSCIncomeMembermsif:AdvisoryAgreementIncentiveRatePreIncentiveFeeNetInvestmentIncomeBelowCatchUpThresholdMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:MSCIncomeMembermsif:AdvisoryAgreementIncentiveRateQuarterlyCatchUpThresholdMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:MSCIncomeMembermsif:AdvisoryAgreementIncentiveRateAnnualizedCatchUpThresholdMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:AdvisoryAgreementIncentiveRatePreIncentiveFeeNetInvestmentIncomeExceedsCatchUpThresholdMembermsif:MSCIncomeMembersrt:AffiliatedEntityMember2020-10-302020-10-300001535778msif:MSCIncomeMembermsif:AdvisoryAgreementBaseManagementFeesMembersrt:AffiliatedEntityMember2023-01-012023-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementBaseManagementFeesMembersrt:AffiliatedEntityMember2022-01-012022-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementSubordinatedIncentiveFeesMembersrt:AffiliatedEntityMember2023-01-012023-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementSubordinatedIncentiveFeesMembersrt:AffiliatedEntityMember2022-01-012022-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementIncentiveFeesCapitalGainsMembersrt:AffiliatedEntityMember2023-01-012023-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementIncentiveFeesCapitalGainsMembersrt:AffiliatedEntityMember2022-01-012022-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementInternalAdministrativeServicesMembersrt:AffiliatedEntityMember2023-01-012023-03-310001535778msif:MSCIncomeMembermsif:AdvisoryAgreementInternalAdministrativeServicesMembersrt:AffiliatedEntityMember2022-01-012022-03-310001535778srt:AffiliatedEntityMembermsif:OfferingCostsMembermsif:MSCIncomeHMSAdviserMember2023-01-012023-03-310001535778srt:AffiliatedEntityMembermsif:OfferingCostsMembermsif:MSCIncomeHMSAdviserMember2023-03-310001535778srt:AffiliatedEntityMembermsif:OfferingCostsMembermsif:MSCIncomeHMSAdviserMember2022-01-012022-03-310001535778msif:DividendReinvestmentPlanMemberus-gaap:SubsequentEventMember2023-05-012023-05-010001535778msif:DividendReinvestmentPlanMemberus-gaap:SubsequentEventMember2023-05-010001535778us-gaap:SubsequentEventMember2023-05-012023-05-010001535778us-gaap:SubsequentEventMember2023-05-010001535778us-gaap:SubsequentEventMember2023-05-112023-05-110001535778GRT Rubber Technologies LLC, Secured Debt 12023-01-012023-03-310001535778GRT Rubber Technologies LLC, Secured Debt 22023-01-012023-03-310001535778GRT Rubber Technologies LLC, Member Units2023-01-012023-03-310001535778Harris Preston Fund Investments, LP Interests (2717 MH, L.P.)2023-01-012023-03-310001535778Copper Trail Fund Investments, LP Interests (CTMH, LP)2023-01-012023-03-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Control Investments2023-01-012023-03-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Control Investments2022-12-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Control Investments2023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2023-01-012023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-12-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2023-03-310001535778AFG Capital Group, LLC, Preferred Member Units2023-01-012023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt 12023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt 12023-01-012023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt 12022-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt 22023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt 22023-01-012023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt 22022-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units 12023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units 12023-01-012023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units 12022-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units 22023-01-012023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units 22022-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units 22023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Warrants2023-01-012023-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Warrants2022-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Warrants2023-03-310001535778ATX Networks Corp., Secured Debt2023-03-310001535778ATX Networks Corp., Secured Debt2023-01-012023-03-310001535778ATX Networks Corp., Unsecured Debt2023-03-310001535778ATX Networks Corp., Unsecured Debt2023-01-012023-03-310001535778ATX Networks Corp., Common Stock2023-01-012023-03-310001535778ATX Networks Corp., Common Stock2023-03-310001535778Barfly Ventures, LLC, Member Units2023-01-012023-03-310001535778Batjer TopCo, LLC, Secured Debt 12023-01-012023-03-310001535778Batjer TopCo, LLC, Secured Debt 22023-01-012023-03-310001535778Batjer TopCo, LLC, Preferred Stock2023-01-012023-03-310001535778Brewer Crane Holdings, LLC, Secured Debt2023-01-012023-03-310001535778Brewer Crane Holdings, LLC, Preferred Member Units2023-01-012023-03-310001535778Centre Technologies Holdings, LLC, Secured Debt 12023-01-012023-03-310001535778Centre Technologies Holdings, LLC, Secured Debt 22023-01-012023-03-310001535778Centre Technologies Holdings, LLC, Preferred Member Units2023-01-012023-03-310001535778Chamberlin Holding LLC, Secured Debt 12023-01-012023-03-310001535778Chamberlin Holding LLC, Secured Debt 22023-01-012023-03-310001535778Chamberlin Holding LLC, Member Units 12023-01-012023-03-310001535778Chamberlin Holding LLC, Member Units 22023-01-012023-03-310001535778Charps, LLC, Preferred Member Units2023-01-012023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 12023-01-012023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 2.12023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 2.12023-01-012023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 2.12022-12-310001535778Clad-Rex Steel, LLC, Secured Debt 32023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 32023-01-012023-03-310001535778Clad-Rex Steel, LLC, Secured Debt 32022-12-310001535778Clad-Rex Steel, LLC, Member Units 12023-01-012023-03-310001535778Clad-Rex Steel, LLC, Member Units 22023-01-012023-03-310001535778Cody Pools, Inc., Secured Debt 12023-01-012023-03-310001535778Cody Pools, Inc., Secured Debt 22023-01-012023-03-310001535778Cody Pools, Inc., Preferred Member Units2023-01-012023-03-310001535778Colonial Electric Company LLC, Secured Debt 12023-01-012023-03-310001535778Colonial Electric Company LLC, Secured Debt 22023-01-012023-03-310001535778Colonial Electric Company LLC, Preferred Member Units2023-01-012023-03-310001535778Datacom, LLC, Secured Debt 12023-01-012023-03-310001535778Datacom, LLC, Secured Debt 22023-01-012023-03-310001535778Datacom, LLC, Preferred Member Units2023-01-012023-03-310001535778Digital Products Holdings LLC, Secured Debt2023-01-012023-03-310001535778Digital Products Holdings LLC, Preferred Member Units2023-01-012023-03-310001535778Direct Marketing Solutions, Inc., Secured Debt 12023-01-012023-03-310001535778Direct Marketing Solutions, Inc., Secured Debt 22023-01-012023-03-310001535778Direct Marketing Solutions, Inc., Preferred Stock2023-01-012023-03-310001535778Flame King Holdings, LLC, Secured Debt 12023-01-012023-03-310001535778Flame King Holdings, LLC, Secured Debt 22023-01-012023-03-310001535778Flame King Holdings, LLC, Preferred Equity2023-01-012023-03-310001535778Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP)2023-01-012023-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt 12023-01-012023-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt 22023-01-012023-03-310001535778Gamber-Johnson Holdings, LLC, Member Units2023-01-012023-03-310001535778GFG Group, LLC., Secured Debt2023-01-012023-03-310001535778GFG Group, LLC., Preferred Member Units2023-01-012023-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 12023-01-012023-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 22023-01-012023-03-310001535778Gulf Publishing Holdings, LLC, Preferred Equity2023-01-012023-03-310001535778Gulf Publishing Holdings, LLC, Member Units2023-01-012023-03-310001535778HPEP 3, L.P., LP Interests (HPEP 3, L.P.)2023-01-012023-03-310001535778HPEP 3, L.P., LP Interests (HPEP 3, L.P.)2022-12-310001535778HPEP 3, L.P., LP Interests (HPEP 3, L.P.)2023-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 12023-01-012023-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 22023-01-012023-03-310001535778Kickhaefer Manufacturing Company, LLC, Preferred Equity2023-01-012023-03-310001535778Kickhaefer Manufacturing Company, LLC, Member Units2023-01-012023-03-310001535778Market Force Information, LLC, Secured Debt2023-01-012023-03-310001535778Market Force Information, LLC, Member Units2023-01-012023-03-310001535778MH Corbin Holding LLC, Secured Debt2023-01-012023-03-310001535778MH Corbin Holding LLC, Preferred Member Units 12023-01-012023-03-310001535778MH Corbin Holding LLC, Preferred Member Units 22023-01-012023-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt 12023-01-012023-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt 22023-01-012023-03-310001535778Mystic Logistics Holdings, LLC, Common Stock2023-01-012023-03-310001535778NexRev LLC, Secured Debt 12023-01-012023-03-310001535778NexRev LLC, Secured Debt 22023-01-012023-03-310001535778NexRev LLC, Preferred Member Units2023-01-012023-03-310001535778NuStep, LLC, Secured Debt 12023-01-012023-03-310001535778NuStep, LLC, Secured Debt 22023-01-012023-03-310001535778NuStep, LLC, Preferred Member Units 12023-01-012023-03-310001535778NuStep, LLC, Preferred Member Units 22023-01-012023-03-310001535778Oneliance, LLC, Secured Debt2023-01-012023-03-310001535778Oneliance, LLC, Preferred Stock2023-01-012023-03-310001535778Orttech Holdings, LLC, Secured Debt 12023-01-012023-03-310001535778Orttech Holdings, LLC, Secured Debt 22023-01-012023-03-310001535778Orttech Holdings, LLC, Preferred Stock2023-01-012023-03-310001535778Robbins Bros. Jewelry, Inc., Secured Debt 12023-01-012023-03-310001535778Robbins Bros. Jewelry, Inc., Secured Debt 22023-01-012023-03-310001535778Robbins Bros. Jewelry, Inc., Preferred Equity2023-01-012023-03-310001535778SI East, LLC, Secured Debt 12023-01-012023-03-310001535778SI East, LLC, Secured Debt 22023-01-012023-03-310001535778SI East, LLC, Preferred Member Units2023-01-012023-03-310001535778Sonic Systems International, LLC, Secured Debt2023-01-012023-03-310001535778Sonic Systems International, LLC, Common Stock2023-01-012023-03-310001535778Student Resource Center, LLC, Secured Debt2023-01-012023-03-310001535778Student Resource Center, LLC, Preferred Equity2023-01-012023-03-310001535778Tedder Industries, LLC, Secured Debt 12023-01-012023-03-310001535778Tedder Industries, LLC, Secured Debt 22023-01-012023-03-310001535778Tedder Industries, LLC, Preferred Member Units 12023-01-012023-03-310001535778Tedder Industries, LLC, Preferred Member Units 12022-12-310001535778Tedder Industries, LLC, Preferred Member Units 22023-01-012023-03-310001535778Tedder Industries, LLC, Preferred Member Units 22022-12-310001535778Trantech Radiator Topco, LLC, Secured Debt 12023-01-012023-03-310001535778Trantech Radiator Topco, LLC, Secured Debt 22023-01-012023-03-310001535778Trantech Radiator Topco, LLC, Common Stock2023-01-012023-03-310001535778Volusion, LLC, Secured Debt 12023-03-310001535778Volusion, LLC, Secured Debt 12023-01-012023-03-310001535778Volusion, LLC, Secured Debt 12022-12-310001535778Volusion, LLC, Secured Debt 22023-01-012023-03-310001535778Volusion, LLC, Secured Debt 22022-12-310001535778Volusion, LLC, Secured Debt 22023-03-310001535778Volusion, LLC, Unsecured Convertible Debt2023-01-012023-03-310001535778Volusion, LLC, Unsecured Convertible Debt2023-03-310001535778Volusion, LLC, Preferred Member Units 12023-01-012023-03-310001535778Volusion, LLC, Preferred Member Units 12022-12-310001535778Volusion, LLC, Preferred Member Units 22023-01-012023-03-310001535778Volusion, LLC, Preferred Member Units 22022-12-310001535778Volusion, LLC, Preferred Member Units 32023-01-012023-03-310001535778Volusion, LLC, Preferred Member Units 32022-12-310001535778Volusion, LLC, Common Stock2023-01-012023-03-310001535778Volusion, LLC, Common Stock2022-12-310001535778Volusion, LLC, Warrants2023-01-012023-03-310001535778Volusion, LLC, Warrants2023-03-310001535778VVS Holdco, LLC, Secured Debt 12023-03-310001535778VVS Holdco, LLC, Secured Debt 12023-01-012023-03-310001535778VVS Holdco, LLC, Secured Debt 12022-12-310001535778VVS Holdco, LLC, Secured Debt 22023-03-310001535778VVS Holdco, LLC, Secured Debt 22023-01-012023-03-310001535778VVS Holdco, LLC, Secured Debt 22022-12-310001535778VVS Holdco, LLC, Preferred Equity2023-01-012023-03-310001535778VVS Holdco, LLC, Preferred Equity2022-12-310001535778VVS Holdco, LLC, Preferred Equity2023-03-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Affiliate Investments2023-01-012023-03-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Affiliate Investments2022-12-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Affiliate Investments2023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-01-012023-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-12-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778us-gaap-supplement:MidwestRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778us-gaap-supplement:NortheastRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778us-gaap-supplement:SoutheastRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778us-gaap-supplement:SouthwestRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2023-03-310001535778us-gaap-supplement:SouthwestRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778us-gaap-supplement:WestRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2023-03-310001535778us-gaap-supplement:WestRegionMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2023-03-310001535778GRT Rubber Technologies LLC, Secured Debt2022-03-310001535778GRT Rubber Technologies LLC, Secured Debt2022-01-012022-03-310001535778GRT Rubber Technologies LLC, Secured Debt2021-12-310001535778GRT Rubber Technologies LLC, Member Units2022-01-012022-03-310001535778GRT Rubber Technologies LLC, Member Units2021-12-310001535778GRT Rubber Technologies LLC, Member Units2022-03-310001535778Harris Preston Fund Investments, LP Interests (2717 MH, L.P.)2022-01-012022-03-310001535778Harris Preston Fund Investments, LP Interests (2717 MH, L.P.)2021-12-310001535778Harris Preston Fund Investments, LP Interests (2717 MH, L.P.)2022-03-310001535778Harris Preston Fund Investments, LP Interests (2717 HPP-MS, L.P.)2022-01-012022-03-310001535778Harris Preston Fund Investments, LP Interests (2717 HPP-MS, L.P.)2021-12-310001535778Harris Preston Fund Investments, LP Interests (2717 HPP-MS, L.P.)2022-03-310001535778Copper Trail Energy Fund I, LP - CTMH, LP Interests (CTMH, LP)2022-01-012022-03-310001535778Copper Trail Energy Fund I, LP - CTMH, LP Interests (CTMH, LP)2021-12-310001535778Copper Trail Energy Fund I, LP - CTMH, LP Interests (CTMH, LP)2022-03-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Control Investments2022-01-012022-03-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Control Investments2021-12-310001535778Other Amounts related to investments transferred to or from other 1940 Act classification during the period, Control Investments2022-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-01-012022-03-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-12-310001535778us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-03-310001535778AFG Capital Group, LLC, Secured Debt2022-03-310001535778AFG Capital Group, LLC, Secured Debt2022-01-012022-03-310001535778AFG Capital Group, LLC, Secured Debt2021-12-310001535778AFG Capital Group, LLC, Preferred Member Units2022-01-012022-03-310001535778AFG Capital Group, LLC, Preferred Member Units2021-12-310001535778AFG Capital Group, LLC, Preferred Member Units2022-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt2022-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt2022-01-012022-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Secured Debt2021-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units2022-01-012022-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units2021-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units2022-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Warrants2022-01-012022-03-310001535778ASK (Analytical Systems Keco Holdings, LLC), Warrants2021-12-310001535778ASK (Analytical Systems Keco Holdings, LLC), Warrants2022-03-310001535778ATX Networks Corp., Secured Debt2022-03-310001535778ATX Networks Corp., Secured Debt2022-01-012022-03-310001535778ATX Networks Corp., Secured Debt2021-12-310001535778ATX Networks Corp., Unsecured Debt2022-03-310001535778ATX Networks Corp., Unsecured Debt2022-01-012022-03-310001535778ATX Networks Corp., Unsecured Debt2021-12-310001535778Barfly Ventures, LLC, Preferred Member Units2022-01-012022-03-310001535778Barfly Ventures, LLC, Preferred Member Units2021-12-310001535778Barfly Ventures, LLC, Preferred Member Units2022-03-310001535778Batjer TopCo, LLC, Secured Debt2022-03-310001535778Batjer TopCo, LLC, Secured Debt2022-01-012022-03-310001535778Batjer TopCo, LLC, Secured Debt2021-12-310001535778Batjer TopCo, LLC, Member Units2022-01-012022-03-310001535778Batjer TopCo, LLC, Member Units2021-12-310001535778Batjer TopCo, LLC, Member Units2022-03-310001535778Brewer Crane Holdings, LLC, Secured Debt2022-03-310001535778Brewer Crane Holdings, LLC, Secured Debt2022-01-012022-03-310001535778Brewer Crane Holdings, LLC, Secured Debt2021-12-310001535778Brewer Crane Holdings, LLC, Preferred Member Units2022-01-012022-03-310001535778Brewer Crane Holdings, LLC, Preferred Member Units2021-12-310001535778Brewer Crane Holdings, LLC, Preferred Member Units2022-03-310001535778Centre Technologies Holdings, LLC, Secured Debt2022-03-310001535778Centre Technologies Holdings, LLC, Secured Debt2022-01-012022-03-310001535778Centre Technologies Holdings, LLC, Secured Debt2021-12-310001535778Centre Technologies Holdings, LLC, Preferred Member Units2022-01-012022-03-310001535778Centre Technologies Holdings, LLC, Preferred Member Units2021-12-310001535778Centre Technologies Holdings, LLC, Preferred Member Units2022-03-310001535778Chamberlin Holding LLC, Secured Debt2022-03-310001535778Chamberlin Holding LLC, Secured Debt2022-01-012022-03-310001535778Chamberlin Holding LLC, Secured Debt2021-12-310001535778Chamberlin Holding LLC, Member Units2022-01-012022-03-310001535778Chamberlin Holding LLC, Member Units2021-12-310001535778Chamberlin Holding LLC, Member Units2022-03-310001535778Charps, LLC, Unsecured Debt2022-03-310001535778Charps, LLC, Unsecured Debt2022-01-012022-03-310001535778Charps, LLC, Unsecured Debt2021-12-310001535778Charps, LLC, Preferred Member Units2022-01-012022-03-310001535778Charps, LLC, Preferred Member Units2021-12-310001535778Charps, LLC, Preferred Member Units2022-03-310001535778Clad-Rex Steel, LLC, Secured Debt 12022-03-310001535778Clad-Rex Steel, LLC, Secured Debt 12022-01-012022-03-310001535778Clad-Rex Steel, LLC, Secured Debt 12021-12-310001535778Clad-Rex Steel, LLC, Secured Debt 22022-03-310001535778Clad-Rex Steel, LLC, Secured Debt 22022-01-012022-03-310001535778Clad-Rex Steel, LLC, Secured Debt 22021-12-310001535778Clad-Rex Steel, LLC, Member Units2022-01-012022-03-310001535778Clad-Rex Steel, LLC, Member Units2021-12-310001535778Clad-Rex Steel, LLC, Member Units2022-03-310001535778Cody Pools, Inc., Secured Debt2022-03-310001535778Cody Pools, Inc., Secured Debt2022-01-012022-03-310001535778Cody Pools, Inc., Secured Debt2021-12-310001535778Cody Pools, Inc., Preferred Member Units2022-01-012022-03-310001535778Cody Pools, Inc., Preferred Member Units2021-12-310001535778Cody Pools, Inc., Preferred Member Units2022-03-310001535778Colonial Electric Company LLC, Secured Debt2022-03-310001535778Colonial Electric Company LLC, Secured Debt2022-01-012022-03-310001535778Colonial Electric Company LLC, Secured Debt2021-12-310001535778Colonial Electric Company LLC, Preferred Member Units2022-01-012022-03-310001535778Colonial Electric Company LLC, Preferred Member Units2021-12-310001535778Colonial Electric Company LLC, Preferred Member Units2022-03-310001535778Datacom, LLC, Secured Debt2022-03-310001535778Datacom, LLC, Secured Debt2022-01-012022-03-310001535778Datacom, LLC, Secured Debt2021-12-310001535778Datacom, LLC, Preferred Member Units2022-01-012022-03-310001535778Datacom, LLC, Preferred Member Units2021-12-310001535778Datacom, LLC, Preferred Member Units2022-03-310001535778Digital Products Holdings LLC, Secured Debt2022-03-310001535778Digital Products Holdings LLC, Secured Debt2022-01-012022-03-310001535778Digital Products Holdings LLC, Secured Debt2021-12-310001535778Digital Products Holdings LLC, Preferred Member Units2022-01-012022-03-310001535778Digital Products Holdings LLC, Preferred Member Units2021-12-310001535778Digital Products Holdings LLC, Preferred Member Units2022-03-310001535778Direct Marketing Solutions, Inc., Secured Debt2022-03-310001535778Direct Marketing Solutions, Inc., Secured Debt2022-01-012022-03-310001535778Direct Marketing Solutions, Inc., Secured Debt2021-12-310001535778Direct Marketing Solutions, Inc., Preferred Stock2022-01-012022-03-310001535778Direct Marketing Solutions, Inc., Preferred Stock2021-12-310001535778Direct Marketing Solutions, Inc., Preferred Stock2022-03-310001535778Flame King Holdings, LLC, Secured Debt 12022-03-310001535778Flame King Holdings, LLC, Secured Debt 12022-01-012022-03-310001535778Flame King Holdings, LLC, Secured Debt 12021-12-310001535778Flame King Holdings, LLC, Secured Debt 22022-03-310001535778Flame King Holdings, LLC, Secured Debt 22022-01-012022-03-310001535778Flame King Holdings, LLC, Secured Debt 22021-12-310001535778Flame King Holdings, LLC, Preferred Equity2022-01-012022-03-310001535778Flame King Holdings, LLC, Preferred Equity2021-12-310001535778Flame King Holdings, LLC, Preferred Equity2022-03-310001535778Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP)2022-01-012022-03-310001535778Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP)2021-12-310001535778Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP)2022-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt2022-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt2022-01-012022-03-310001535778Gamber-Johnson Holdings, LLC, Secured Debt2021-12-310001535778Gamber-Johnson Holdings, LLC, Member Units2022-01-012022-03-310001535778Gamber-Johnson Holdings, LLC, Member Units2021-12-310001535778Gamber-Johnson Holdings, LLC, Member Units2022-03-310001535778GFG Group, LLC., Secured Debt2022-03-310001535778GFG Group, LLC., Secured Debt2022-01-012022-03-310001535778GFG Group, LLC., Secured Debt2021-12-310001535778GFG Group, LLC., Preferred Member Units2022-01-012022-03-310001535778GFG Group, LLC., Preferred Member Units2021-12-310001535778GFG Group, LLC., Preferred Member Units2022-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 12022-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 12022-01-012022-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 12021-12-310001535778Gulf Publishing Holdings, LLC, Secured Debt 22022-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 22022-01-012022-03-310001535778Gulf Publishing Holdings, LLC, Secured Debt 22021-12-310001535778HPEP 3, L.P., LP Interests (HPEP 3, L.P.)2022-01-012022-03-310001535778HPEP 3, L.P., LP Interests (HPEP 3, L.P.)2021-12-310001535778HPEP 3, L.P., LP Interests (HPEP 3, L.P.)2022-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 12022-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 12022-01-012022-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 12021-12-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 22022-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 22022-01-012022-03-310001535778Kickhaefer Manufacturing Company, LLC, Secured Debt 22021-12-310001535778Kickhaefer Manufacturing Company, LLC, Member Units 12022-01-012022-03-310001535778Kickhaefer Manufacturing Company, LLC, Member Units 12021-12-310001535778Kickhaefer Manufacturing Company, LLC, Member Units 12022-03-310001535778Kickhaefer Manufacturing Company, LLC, Member Units 22022-01-012022-03-310001535778Kickhaefer Manufacturing Company, LLC, Member Units 22021-12-310001535778Kickhaefer Manufacturing Company, LLC, Member Units 22022-03-310001535778Market Force Information, LLC, Secured Debt2022-03-310001535778Market Force Information, LLC, Secured Debt2022-01-012022-03-310001535778Market Force Information, LLC, Secured Debt2021-12-310001535778MH Corbin Holding LLC, Secured Debt2022-03-310001535778MH Corbin Holding LLC, Secured Debt2022-01-012022-03-310001535778MH Corbin Holding LLC, Secured Debt2021-12-310001535778MH Corbin Holding LLC, Preferred Member Units2022-01-012022-03-310001535778MH Corbin Holding LLC, Preferred Member Units2021-12-310001535778MH Corbin Holding LLC, Preferred Member Units2022-03-310001535778Oneliance, LLC, Preferred Stock2022-01-012022-03-310001535778Oneliance, LLC, Preferred Stock2021-12-310001535778Oneliance, LLC, Preferred Stock2022-03-310001535778Oneliance, LLC, Secured Debt2022-03-310001535778Oneliance, LLC, Secured Debt2022-01-012022-03-310001535778Oneliance, LLC, Secured Debt2021-12-310001535778Orttech Holdings, LLC, Secured Debt2022-03-310001535778Orttech Holdings, LLC, Secured Debt2022-01-012022-03-310001535778Orttech Holdings, LLC, Secured Debt2021-12-310001535778Orttech Holdings, LLC, Preferred Stock2022-01-012022-03-310001535778Orttech Holdings, LLC, Preferred Stock2021-12-310001535778Orttech Holdings, LLC, Preferred Stock2022-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt2022-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt2022-01-012022-03-310001535778Mystic Logistics Holdings, LLC, Secured Debt2021-12-310001535778Mystic Logistics Holdings, LLC, Common Stock2022-01-012022-03-310001535778Mystic Logistics Holdings, LLC, Common Stock2021-12-310001535778Mystic Logistics Holdings, LLC, Common Stock2022-03-310001535778NexRev LLC, Secured Debt2022-03-310001535778NexRev LLC, Secured Debt2022-01-012022-03-310001535778NexRev LLC, Secured Debt2021-12-310001535778NexRev LLC, Preferred Member Units2022-01-012022-03-310001535778NexRev LLC, Preferred Member Units2021-12-31