10-Q 1 main-20220930.htm 10-Q main-20220930
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Jewelry, Inc., Secured Debt One December 15, 20212022-09-300001396440Robbins Bros. Jewelry, Inc., Secured Debt Two December 15, 20212022-09-300001396440Robbins Bros. Jewelry, Inc., Preferred Equity December 15, 20212022-09-300001396440main:RobbinsBrosJewelryIncMember2022-09-300001396440Tedder Industries, LLC, Secured Debt One August 31, 20182022-09-300001396440Tedder Industries, LLC, Secured Debt Two August 31, 20182022-09-300001396440Tedder Industries, LLC, Preferred Member Units August 31, 20182022-09-300001396440main:TedderIndustriesLLCMember2022-09-300001396440Televerde, LLC, Member Units January 06, 20112022-09-300001396440Televerde, LLC, Preferred Stock January 26, 20222022-09-300001396440main:TeleverdeLLCMember2022-09-300001396440Trantech Radiator Topco, LLC, Secured Debt One May 31, 20192022-09-300001396440Trantech Radiator Topco, LLC, Secured Debt Two May 31, 20192022-09-300001396440Trantech Radiator Topco, LLC, Common Stock May 31, 20192022-09-300001396440main:TrantechRadiatorTopcoLLCMember2022-09-300001396440Vision Interest, Inc., Series A Preferred Stock December 23, 20112022-09-300001396440VVS Holdco LLC, Secured Debt One December 01, 20212022-09-300001396440VVS Holdco LLC, Secured Debt Two December 01, 20212022-09-300001396440VVS Holdco LLC, Preferred Equity December 01, 20212022-09-300001396440main:VVSHoldcoLLCMember2022-09-300001396440Ziegler’s NYPD, LLC, Secured Debt One June 01, 20152022-09-300001396440Ziegler’s NYPD, LLC, Secured Debt Two October 01, 20082022-09-300001396440Ziegler’s NYPD, LLC, Secured Debt Three October 01, 20082022-09-300001396440Ziegler’s NYPD, LLC, Preferred Member Units June 30, 20152022-09-300001396440Ziegler’s NYPD, LLC, Warrants July 01, 20152022-09-300001396440main:ZieglersNYPDLLCMember2022-09-300001396440AAC Holdings, Inc., Secured Debt December 11, 20202022-09-300001396440AAC Holdings, Inc., Common Stock December 11, 20202022-09-300001396440AAC Holdings, Inc., Warrants December 11, 20202022-09-300001396440main:AACHoldingsIncMember2022-09-300001396440AFG Capital Group, LLC, Preferred Member Units November 07, 20142022-09-300001396440ATX Networks Corp., Secured Debt September 01, 20212022-09-300001396440ATX Networks Corp., Unsecured Debt September 01, 20212022-09-300001396440ATX Networks Corp., Common Stock September 01, 20212022-09-300001396440main:ATXNetworksCorpMember2022-09-300001396440BBB Tank Services, LLC, Unsecured Debt One April 08, 20162022-09-300001396440BBB Tank Services, LLC, Unsecured Debt Two April 08, 20162022-09-300001396440BBB Tank Services, LLC, Member Units April 08, 20162022-09-300001396440BBB Tank Services, LLC, Preferred Stock (non-voting) December 17, 20182022-09-300001396440main:BBBTankServicesLLCMember2022-09-300001396440Boccella Precast Products LLC, Secured Debt September 23, 20212022-09-300001396440Boccella Precast Products LLC, Member Units June 30, 20172022-09-300001396440main:BoccellaPrecastProductsLLCMember2022-09-300001396440Buca C, LLC, Secured Debt June 30, 20152022-09-300001396440Buca C, LLC, Preferred Member Units June 30, 20152022-09-300001396440main:BucaCLLCMember2022-09-300001396440Career Team Holdings, LLC, Secured Debt One December 17, 20212022-09-300001396440Career Team Holdings, LLC, Secured Debt Two December 17, 20212022-09-300001396440Career Team Holdings, LLC, Common Stock December 17, 20212022-09-300001396440main:CareerTeamHoldingsLLCMember2022-09-300001396440Chandler Signs Holdings, LLC, Class A Units January 04, 20162022-09-300001396440Classic H&G Holdings, LLC, Secured Debt One March 12, 20202022-09-300001396440Classic H&G Holdings, LLC, Secured Debt Two March 12, 20202022-09-300001396440Classic H&G Holdings, LLC, Preferred Member Units March 12, 20202022-09-300001396440main:ClassicHGHoldingsLLCMember2022-09-300001396440Congruent Credit Opportunities Funds, LP Interests (Congruent Credit Opportunities Fund III, LP) February 04, 20152022-09-300001396440DMA Industries, LLC, Secured Debt November 19, 20212022-09-300001396440DMA Industries, LLC, Preferred Equity November 19, 20212022-09-300001396440main:DMAIndustriesLLCMember2022-09-300001396440Dos Rios Partners, LP Interests (Dos Rios Partners, LP) April 25, 20132022-09-300001396440Dos Rios Partners, LP Interests (Dos Rios Partners - A, LP) April 25, 20132022-09-300001396440main:DosRiosPartnersMember2022-09-300001396440Dos Rios Stone Products LLC, Class A Preferred Units June 27, 20162022-09-300001396440EIG Fund Investments, LP Interests (EIG Global Private Debt Fund-A, L.P.) November 06, 20152022-09-300001396440Freeport Financial Funds, LP Interests (Freeport Financial SBIC Fund LP) March 23, 20152022-09-300001396440Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP) July 31, 20152022-09-300001396440main:FreeportFinancialFundsMember2022-09-300001396440GFG Group, LLC., Secured Debt March 31, 20212022-09-300001396440GFG Group, LLC., Preferred Member Units March 31, 20212022-09-300001396440main:GFGGroupLLCMember2022-09-300001396440Harris Preston Fund Investments, LP Interests (HPEP 3, L.P.) August 09, 20172022-09-300001396440Harris Preston Fund Investments, LP Interests (HPEP 4, L.P.) July 12, 20222022-09-300001396440Harris Preston Fund Investments, LP Interests (423 COR, LP) June 02, 20222022-09-300001396440main:HarrisPrestonFundInvestmentsTwoMember2022-09-300001396440Hawk Ridge Systems, LLC, Secured Debt One December 02, 20162022-09-300001396440Hawk Ridge Systems, LLC, Secured Debt Two December 02, 20162022-09-300001396440Hawk Ridge Systems, LLC, Preferred Member Units One December 02, 20162022-09-300001396440Hawk Ridge Systems, LLC, Preferred Member Units Two December 02, 20162022-09-300001396440main:HawkRidgeSystemsLLCMember2022-09-300001396440Houston Plating and Coatings, LLC, Unsecured Convertible Debt May 01, 20172022-09-300001396440Houston Plating and Coatings, LLC, Member Units January 08, 20032022-09-300001396440main:HoustonPlatingAndCoatingsLLCMember2022-09-300001396440I-45 SLF LLC, Investment Partnership October 20, 2015 2022-09-300001396440Iron-Main Investments, LLC, Secured Debt One August 02, 20212022-09-300001396440Iron-Main Investments, LLC, Secured Debt Two September 01, 20212022-09-300001396440Iron-Main Investments, LLC, Secured Debt Three November 15, 20212022-09-300001396440Iron-Main Investments, LLC, Secured Debt Four November 15, 20212022-09-300001396440Iron-Main Investments, LLC, Common Stock August 03, 20212022-09-300001396440main:IronMainInvestmentsLLCMember2022-09-300001396440OnAsset Intelligence, Inc., Secured Debt May 20, 20142022-09-300001396440OnAsset Intelligence, Inc., Secured Debt March 21, 20142022-09-300001396440OnAsset Intelligence, Inc., Secured Debt May 10, 20132022-09-300001396440OnAsset Intelligence, Inc., Secured Debt April 18, 20112022-09-300001396440OnAsset Intelligence, Inc., Unsecured Debt June 05, 20172022-09-300001396440OnAsset Intelligence, Inc., Preferred Stock April 18, 20112022-09-300001396440OnAsset Intelligence, Inc., Common Stock April 15, 20112022-09-300001396440OnAsset Intelligence, Inc., Warrants April 18, 20112022-09-300001396440main:OnAssetIntelligenceIncMember2022-09-300001396440Oneliance, LLC, Secured Debt One August 06, 20212022-09-300001396440Oneliance, LLC, Secured Debt Two August 06, 20212022-09-300001396440Oneliance, LLC, Preferred Stock August 06, 20212022-09-300001396440main:OnelianceLLCMember2022-09-300001396440Rocaceia, LLC Secured Debt June 30, 20152022-09-300001396440Rocaceia, LLC Preferred Member Unit January 08, 20132022-09-300001396440main:RocaceiaLLCQualityLeaseAndRentalHoldingsLLCMember2022-09-300001396440SI East, LLC, Senior Debt One August 31, 20182022-09-300001396440SI East, LLC, Senior Debt Two August 31, 20182022-09-300001396440SI East, LLC, Preferred Member Units August 31, 20182022-09-300001396440main:SIEastLLCMember2022-09-300001396440Slick Innovations, LLC, Secured Debt September 13, 20182022-09-300001396440Slick Innovations, LLC, Common Stock September 13, 20182022-09-300001396440Slick Innovations, LLC, Warrants September 13, 20182022-09-300001396440main:SlickInnovationsLLCMember2022-09-300001396440Sonic Systems International, LLC, Secured Debt August 20, 20212022-09-300001396440Sonic Systems International, LLC, Common Stock August 20, 20212022-09-300001396440main:SonicSystemsInternationalLLCMember2022-09-300001396440Superior Rigging & Erecting Co., Secured Debt August 31, 20202022-09-300001396440Superior Rigging & Erecting Co., Preferred Member Units August 31, 20202022-09-300001396440main:SuperiorRiggingErectingCoMember2022-09-300001396440The Affiliati Network, LLC., Secured Debt One August 09, 20212022-09-300001396440The Affiliati Network, LLC., Secured Debt August 09, 20212022-09-300001396440The Affiliati Network, LLC., Secured Debt Two August 09, 20212022-09-300001396440The Affiliati Network, LLC., Preferred Stock August 09, 20212022-09-300001396440main:TheAffiliatiNetworkLLCMember2022-09-300001396440UnionRock Energy Fund II, LP, LP Interests June 15, 2020 2022-09-300001396440UniTek Global Services, Inc.., Secured Debt October 15, 20182022-09-300001396440UniTek Global Services, Inc.., Secured Debt August 27, 20182022-09-300001396440UniTek Global Services, Inc.., Secured Convertible Debt January 1, 20182022-09-300001396440UniTek Global Services, Inc.., Preferred Stock August 29, 20192022-09-300001396440UniTek Global Services, Inc.., Preferred Stock August 21, 20182022-09-300001396440UniTek Global Services, Inc.., Preferred Stock June 30, 20172022-09-300001396440UniTek Global Services, Inc.., Preferred Stock January 15, 20152022-09-300001396440UniTek Global Services, Inc.., Common Stock April 01, 20202022-09-300001396440main:UniTekGlobalServicesIncMember2022-09-300001396440Universal Wellhead Services Holdings, LLC, Preferred Member Units December 07, 20162022-09-300001396440Universal Wellhead Services Holdings, LLC, Member Units December 07, 20162022-09-300001396440main:UniversalWellheadServicesHoldingsLLCMember2022-09-300001396440Volusion, LLC, Secured Debt January 26, 20152022-09-300001396440Volusion, LLC, Unsecured Convertible Debt May 16, 20182022-09-300001396440Volusion, LLC, Preferred Member Units, January 26, 20152022-09-300001396440Volusion, LLC, Warrants, January 26, 20152022-09-300001396440main:VolusionLLCMember2022-09-300001396440AB Centers Acquisition Corporation, Secured Debt One September 06, 20222022-09-300001396440AB Centers Acquisition Corporation, Secured Debt Two September 06, 20222022-09-300001396440AB Centers Acquisition Corporation, Secured Debt Three September 06, 20222022-09-300001396440main:ABCentersAcquisitionCorporationMember2022-09-300001396440Acousti Engineering Company of Florida, Secured Debt One November 02, 20202022-09-300001396440Acousti Engineering Company of Florida, Secured Debt Two November 02, 20202022-09-300001396440Acousti Engineering Company of Florida, Secured Debt Two May 26 20212022-09-300001396440main:AcoustiEngineeringCompanyOfFloridaMember2022-09-300001396440Acumera, Inc., Secured Debt One June 28, 20222022-09-300001396440Acumera, Inc., Secured Debt Two June 28, 20222022-09-300001396440main:AcumeraIncMember2022-09-300001396440Adams Publishing Group, LLC, Secured Debt One March 11, 20222022-09-300001396440Adams Publishing Group, LLC, Secured Debt Two March 11, 20222022-09-300001396440main:AdamsPublishingGroupLLCMember2022-09-300001396440ADS Tactical, Inc. Secured Debt March 29, 20212022-09-300001396440AMEREQUIP LLC., Secured Debt One August 31, 20222022-09-300001396440AMEREQUIP LLC., Secured Debt Two August 31, 20222022-09-300001396440AMEREQUIP LLC., Common Stock August 31, 20222022-09-300001396440main:AMEREQUIPLLCMember2022-09-300001396440American Health Staffing Group, Inc., Secured Debt One November 19, 20212022-09-300001396440American Health Staffing Group, Inc., Secured Debt Two November 19, 20212022-09-300001396440main:AmericanHealthStaffingGroupIncMember2022-09-300001396440American Nuts, LLC, Secured Debt one March 11, 20222022-09-300001396440American Nuts, LLC, Secured Debt Two March 11, 20222022-09-300001396440main:AmericanNutsLLCMember2022-09-300001396440American Teleconferencing Services, Ltd., Secured Debt September 17, 20212022-09-300001396440American Teleconferencing Services, Ltd., Secured Debt One, May 19, 20162022-09-300001396440main:AmericanTeleconferencingServicesLtdMember2022-09-300001396440ArborWorks, LLC, Secured Debt One November 09, 20212022-09-300001396440ArborWorks, LLC, Secured Debt Two November 09, 20212022-09-300001396440ArborWorks, LLC Common Equity November 09, 20212022-09-300001396440main:ArborWorksLLCMember2022-09-300001396440Archer Systems, LLC, Secured Debt One August 11, 20222022-09-300001396440Archer Systems, LLC, Secured Debt Two August 11, 20222022-09-300001396440Archer Systems, LLC., Common Stock August 11, 20222022-09-300001396440main:ArcherSystemsLLCMember2022-09-300001396440Arrow International, Inc, Secured Debt December 21, 20202022-09-300001396440ATS Operating, LLC, Secured Debt One January 18,20222022-09-300001396440ATS Operating, LLC, Secured Debt Two January 18,20222022-09-300001396440ATS Operating, LLC, Secured Debt Three January 18,20222022-09-300001396440ATS Operating, LLC, Common Stock January 18,2022.2022-09-300001396440main:ATSOperatingLLCMember2022-09-300001396440AVEX Aviation Holdings, LLC, Secured Debt One December 15, 20212022-09-300001396440AVEX Aviation Holdings, LLC, Secured Debt Two December 15, 20212022-09-300001396440AVEX Aviation Holdings, LLC, Common Equity Two December 15, 20212022-09-300001396440main:AVEXAviationHoldingsLLCMember2022-09-300001396440Berry Aviation, Inc., Secured Debt July 06, 20182022-09-300001396440Berry Aviation, Inc., Preferred Member Units One July 06, 20182022-09-300001396440Berry Aviation, Inc., Preferred Member Units Two November 12, 20192022-09-300001396440main:BerryAviationIncMember2022-09-300001396440Bettercloud, Inc., Secured Debt One June 30, 20222022-09-300001396440Bettercloud, Inc., Secured Debt Two June 30, 20222022-09-300001396440main:BettercloudIncMember2022-09-300001396440Binswanger Enterprises, LLC, Member Units March 10, 20172022-09-300001396440Bluestem Brands, Inc, Secured Debt August 28, 20202022-09-300001396440Bluestem Brands, Inc.., Common Stock October 01, 20202022-09-300001396440main:BluestemBrandsIncMember2022-09-300001396440Brainworks Software, LLC, Secured Debt One August 12, 20142022-09-300001396440Brainworks Software, LLC, Secured Debt Two August 12, 20142022-09-300001396440main:BrainworksSoftwareLLCMember2022-09-300001396440Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund V, LP) July 12, 20212022-09-300001396440Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund III, LP) July 21, 20142022-09-300001396440Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund IV, LP) November 26, 20162022-09-300001396440main:BrightwoodCapitalFundInvestmentsMember2022-09-300001396440Burning Glass Intermediate Holding Company, Inc., Secured Debt One June 14, 20212022-09-300001396440Burning Glass Intermediate Holding Company, Inc., Secured Debt Two June 14, 20212022-09-300001396440main:BurningGlassIntermediateHoldingCompanyIncMember2022-09-300001396440Cadence Aerospace LLC, Secured Debt November 14, 20172022-09-300001396440CAI Software LLC., Preferred Equity One December 13, 20212022-09-300001396440CAI Software LLC., Preferred Equity Two December 13, 20212022-09-300001396440main:CAISoftwareLLCMember2022-09-300001396440Camin Cargo Control, Inc., Secured Debt June 14, 20212022-09-300001396440CaseWorthy, Inc., Secured Debt One May 18, 20222022-09-300001396440CaseWorthy, Inc., Secured Debt Two May 18, 20222022-09-300001396440CaseWorthy, Inc., Secured Debt Three May 18, 20222022-09-300001396440main:CaseWorthyIncMember2022-09-300001396440Channel Partners Intermediateco, LLC, Secured Debt One February 07, 20222022-09-300001396440Channel Partners Intermediateco, LLC, Secured Debt Two February 07, 20222022-09-300001396440main:ChannelPartnersIntermediatecoLLCMember2022-09-300001396440Clarius BIGS, LLC , Secured Debt September 23,20142022-09-300001396440Computer Data Source, LLC, Secured Debt One August 06, 20212022-09-300001396440Computer Data Source, LLC, Secured Debt Two August 06, 20212022-09-300001396440main:ComputerDataSourceLLCMember2022-09-300001396440Construction Supply Investments, LLC., Member Units December 29, 20162022-09-300001396440 Dalton US Inc., Secured Debt One August 16, 20222022-09-300001396440 Dalton US Inc., Secured Debt Two August 16, 20222022-09-300001396440 Dalton US Inc., Secured Debt Three August 16, 20222022-09-300001396440 Dalton US Inc., Common Stock August 16, 20222022-09-300001396440main:DaltonUSIncMember2022-09-300001396440DTE Enterprises LLC Secured Debt One April 13, 20182022-09-300001396440DTE Enterprises LLC Secured Debt Two April 13, 20182022-09-300001396440DTE Enterprises LLC Class A Preferred Member Units April 13, 20182022-09-300001396440DTE Enterprises LLC Class A Class AA Preferred Member Units (non-voting) April 13, 20182022-09-300001396440main:DTEEnterprisesLLCMember2022-09-300001396440Dynamic Communities, LLC, Secured Debt One July 17, 20182022-09-300001396440Dynamic Communities, LLC, Secured Debt Two September 28, 20222022-09-300001396440Dynamic Communities, LLC, Secured Debt Three September 28, 20222022-09-300001396440main:DynamicCommunitiesLLCMember2022-09-300001396440Eastern Wholesale Fence LLC, Secured Debt One November 19, 20202022-09-300001396440Eastern Wholesale Fence LLC, Secured Debt Two November 19, 20202022-09-300001396440Eastern Wholesale Fence LLC, Secured Debt Three November 19, 20202022-09-300001396440main:EasternWholesaleFenceLLCMember2022-09-300001396440Emerald Technologies Acquisition Co, Inc., Secured Debt February 10, 20222022-09-300001396440EnCap Energy Fund Investments., LP Interests (EnCap Energy Capital Fund VIII, L.P.) January 22, 20152022-09-300001396440EnCap Energy Fund Investments., LP Interests LP Interests (EnCap Energy Capital Fund VIII Co- Investors, L.P.) January 21, 20152022-09-300001396440EnCap Energy Fund Investments., LP Interests LP Interests (EnCap Energy Capital Fund IX, L.P.) January 22, 20152022-09-300001396440EnCap Energy Fund Investments., LP Interests LP Interests (LP Interests (EnCap Energy Capital Fund X, L.P.) March 25, 20152022-09-300001396440EnCap Energy Fund Investments., LP Interests (EnCap Flatrock Midstream Fund II, L.P.) March 30, 20152022-09-300001396440EnCap Energy Fund Investments., LP Interests (EnCap Flatrock Midstream Fund III, L.P.) March 27, 20152022-09-300001396440main:EnCapEnergyFundInvestmentsMember2022-09-300001396440Engineering Research & Consulting, LLC, Secured Debt One May 23, 20222022-09-300001396440Engineering Research & Consulting, LLC, Secured Debt Two May 23, 20222022-09-300001396440main:EngineeringResearchConsultingLLCMember2022-09-300001396440EPIC Y-Grade Services, LP, Secured Debt June 22, 20182022-09-300001396440Event Holdco, LLC, Secured Debt One December 22, 20212022-09-300001396440Event Holdco, LLC, Secured Debt Two December 22, 20212022-09-300001396440main:EventHoldcoLLCMember2022-09-300001396440Flip Electronics LLC, Secured Debt One March 24, 20222022-09-300001396440Flip Electronics LLC, Secured Debt Two January 04, 20212022-09-300001396440main:FlipElectronicsLLCMember2022-09-300001396440Fuse, LLC, Secured Debt June 30, 20192022-09-300001396440Fuse, LLC, Common Stock June 30, 20192022-09-300001396440main:FuseLLCMember2022-09-300001396440GeoStabilization International (GSI), Secured Debt January 02, 20192022-09-300001396440GS HVAM Intermediate, LLC, Secured Debt One October 18, 20192022-09-300001396440GS HVAM Intermediate, LLC, Secured Debt Two October 18, 20192022-09-300001396440main:GSHVAMIntermediateLLCMember2022-09-300001396440GULF PACIFIC ACQUISITION, LLC, Secured Debt One September 30, 20222022-09-300001396440GULF PACIFIC ACQUISITION, LLC, Secured Debt Two September 30, 20222022-09-300001396440GULF PACIFIC ACQUISITION, LLC, Secured Debt Three September 30, 20222022-09-300001396440main:GULFPACIFICACQUISITIONLLCMember2022-09-300001396440HDC/HW Intermediate Holdings, Secured Debt One December 21, 20182022-09-300001396440HDC/HW Intermediate Holdings, Secured Debt Two December 21, 20182022-09-300001396440main:HDCHWIntermediateHoldingsMember2022-09-300001396440HEADLANDS OP-CO LLC, Secured Debt One August 01, 20222022-09-300001396440HEADLANDS OP-CO LLC, Secured Debt Two August 01, 20222022-09-300001396440HEADLANDS OP-CO LLC, Secured Debt Three August 01, 20222022-09-300001396440main:HEADLANDSOPCOLLCMember2022-09-300001396440Heartland Dental, LLC, Secured Debt September 09, 2020,2022-09-300001396440HOWLCO LLC, Secured Debt August 11, 20212022-09-300001396440Hybrid Promotions, LLC, Secured Debt June 30, 20212022-09-300001396440IG Parent Corporation, Secured Debt One July 30, 20212022-09-300001396440IG Parent Corporation, Secured Debt Two July 30, 20212022-09-300001396440main:IGParentCorporationMember2022-09-300001396440Implus Footcare, LLC, Secured Debt June 01, 20172022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Secured Debt One August 20, 20202022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Secured Debt Two December 10, 20202022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) One December 10, 20202022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) Two December 10, 20202022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Member Units November 20, 20182022-09-300001396440Independent Pet Partners Intermediate Holding, Member Units November 20, 20182022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Warrants One November 20, 20182022-09-300001396440main:IndependentPetPartnersIntermediateHoldingsLLCMember2022-09-300001396440Industrial Services Acquisition, LLC, Secured Debt One August 13, 20212022-09-300001396440Industrial Services Acquisition, LLC, Secured Debt Two August 13, 20212022-09-300001396440Industrial Services Acquisition, LLC, Preferred Member Units One January 31, 20212022-09-300001396440Industrial Services Acquisition, LLC, Preferred Member Units Two May 17, 20192022-09-300001396440Industrial Services Acquisition, LLC, Member Units June 17, 20162022-09-300001396440main:IndustrialServicesAcquisitionLLCMember2022-09-300001396440Infolinks Media Buyco, LLC, Secured Debt One November 01, 20212022-09-300001396440Infolinks Media Buyco, LLC, Secured Debt Two November 01, 20212022-09-300001396440main:InfolinksMediaBuycoLLCMember2022-09-300001396440Interface Security Systems, L.L.C, Secured Debt One December 09,20212022-09-300001396440Interface Security Systems, L.L.C, Secured Debt Two August 07,20192022-09-300001396440Interface Security Systems, L.L.C, Common Stock December 07,20212022-09-300001396440main:InterfaceSecuritySystemsLLCMember2022-09-300001396440Intermedia Holdings, Inc., Secured Debt August 03, 20182022-09-300001396440Invincible Boat Company, LLC., Secured Debt One August 28, 20192022-09-300001396440Invincible Boat Company, LLC., Secured Debt Two August 28, 20192022-09-300001396440main:InvincibleBoatCompanyLLCMember2022-09-300001396440INW Manufacturing, LLC, Secured Debt May 19, 20212022-09-300001396440Isagenix International, LLC, Secured Debt June 21, 20182022-09-300001396440Jackmont Hospitality, Inc., Secured Debt November 08, 20212022-09-300001396440Jackmont Hospitality, Inc., Preferred Equity November 08, 20212022-09-300001396440main:JackmontHospitalityIncMember2022-09-300001396440Joerns Healthcare, LLC, Secured Debt One November 15, 20212022-09-300001396440Joerns Healthcare, LLC, Secured Debt Two August 21, 20192022-09-300001396440Joerns Healthcare, LLC, Common Stock August 21, 20192022-09-300001396440main:JoernsHealthcareLLCMember2022-09-300001396440JTI Electrical & Mechanical, LLC, Secured Debt One December 22, 20212022-09-300001396440JTI Electrical & Mechanical, LLC, Secured Debt Two December 22, 20212022-09-300001396440JTI Electrical & Mechanical, LLC, Common Equity December 22, 20212022-09-300001396440main:JTIElectricalMechanicalLLCMember2022-09-300001396440KMS, LLC, Secured Debt One October 04, 20212022-09-300001396440KMS, LLC, Secured Debt Two October 04, 20212022-09-300001396440main:KMSLLCMember2022-09-300001396440Kore Wireless Group Inc., Secured Debt December 11, 20222022-09-300001396440Lightbox Holdings, L.P., Secured Debt May 09, 20192022-09-300001396440LKCM Headwater Investments I, L.P., LP Interests January 25, 20132022-09-300001396440LL Management, Inc., Secured Debt One May 02, 20192022-09-300001396440LL Management, Inc., Secured Debt Two May 02, 20192022-09-300001396440LL Management, Inc., Secured Debt Three May 12, 20192022-09-300001396440main:LLManagementIncMember2022-09-300001396440LLFlex, LLC, Secured Debt August 16, 20212022-09-300001396440Logix Acquisition Company, LLC, Secured Debt January 08, 20182022-09-300001396440Looking Glass Investments, LLC., Member Units July 01, 20152022-09-300001396440Mac Lean-Fogg Company, Secured Debt One April 22, 20192022-09-300001396440Mac Lean-Fogg Company, Secured Debt Two April 22, 20192022-09-300001396440Mac Lean-Fogg Company, Preferred Stock October 01, 20192022-09-300001396440main:MacLeanFoggCompanyMember2022-09-300001396440Mako Steel, LP, Secured Debt One March 15, 20212022-09-300001396440Mako Steel, LP, Secured Debt Two March 15, 20212022-09-300001396440main:MakoSteelLPMember2022-09-300001396440MB2 Dental Solutions, LLC, Secured Debt One January 28,20212022-09-300001396440MB2 Dental Solutions, LLC, Secured Debt Two January 28,20212022-09-300001396440main:MB2DentalSolutionsLLCMember2022-09-300001396440Microbe Formulas, LLC, Secured Debt One April 04, 20222022-09-300001396440Microbe Formulas, LLC, Secured Debt Two April 04, 20222022-09-300001396440main:MicrobeFormulasLLCMember2022-09-300001396440Mills Fleet Farm Group, LLC, Secured Debt October 24, 20182022-09-300001396440MonitorUS Holding, LLC, Secured Debt One May 24, 20222022-09-300001396440MonitorUS Holding, LLC, Secured Debt Two May 24, 20222022-09-300001396440MonitorUS Holding, LLC, Secured Debt Three May 24, 20222022-09-300001396440MonitorUS Holding, LLC, Common Stock August 30, 20222022-09-300001396440main:MonitorUSHoldingLLCMember2022-09-300001396440NBG Acquisition Inc, Secured Debt April 28, 20172022-09-300001396440NinjaTrader, LLC, Secured Debt One December 18, 20192022-09-300001396440NinjaTrader, LLC, Secured Debt Two December 18, 20192022-09-300001396440NinjaTrader, LLC, Secured Debt Three December 18, 20192022-09-300001396440main:NinjaTraderLLCMember2022-09-300001396440NNE Partners, LLC, Secured Debt March 02, 20172022-09-300001396440Northstar Group Services, Inc, Secured Debt November 01, 20212022-09-300001396440NTM Acquisition Corp., Secured Debt July 12, 20162022-09-300001396440NWN Corporation, Secured Debt One May 07, 20212022-09-300001396440NWN Corporation, Secured Debt Two May 07, 20212022-09-300001396440main:NWNCorporationMember2022-09-300001396440Ospemifene Royalty Sub LLC, Secured Debt July 08, 20132022-09-300001396440OVG Business Services, LLC, Secured Debt November 29, 20212022-09-300001396440Paragon Healthcare, Inc., Secured Debt One January 19, 20222022-09-300001396440Paragon Healthcare, Inc., Secured Debt Two January 19, 20222022-09-300001396440Paragon Healthcare, Inc., Secured Debt Three January 19, 20222022-09-300001396440main:ParagonHealthcareIncMember2022-09-300001396440Project Eagle Holdings, LLC, Secured Debt One July 06, 20202022-09-300001396440Project Eagle Holdings, LLC, Secured Debt Two July 06, 20202022-09-300001396440main:ProjectEagleHoldingsLLCMember2022-09-300001396440PTL US Bidco, Inc, Secured Debt One August 19, 20222022-09-300001396440PTL US Bidco, Inc, Secured Debt Two August 19, 20222022-09-300001396440main:PTLUSBidcoIncMember2022-09-300001396440RA Outdoors LLC, Secured Debt One April 08, 20212022-09-300001396440RA Outdoors LLC, Secured Debt Two April 08, 20212022-09-300001396440main:RAOutdoorsLLCMember2022-09-300001396440Research Now Group, Inc. and Survey Sampling International, LLC, Secured Debt December 29, 20172022-09-300001396440RM Bidder, LLC., Member Units November 12, 20152022-09-300001396440RM Bidder, LLC., Warrants November 12, 20152022-09-300001396440main:RMBidderLLCMember2022-09-300001396440Roof Opco, LLC, Secured Debt One August 27, 20212022-09-300001396440Roof Opco, LLC, Secured Debt Two August 27, 20212022-09-300001396440Roof Opco, LLC, Secured Debt Three August 27, 20212022-09-300001396440main:RoofOpcoLLCMember2022-09-300001396440RTIC Subsidiary Holdings, LLC, Secured Debt One September 01, 20202022-09-300001396440RTIC Subsidiary Holdings, LLC, Secured Debt Two September 01, 20202022-09-300001396440main:RTICSubsidiaryHoldingsLLCMember2022-09-300001396440Rug Doctor, LLC., Secured Debt One July 16, 20212022-09-300001396440Rug Doctor, LLC., Secured Debt Two July 16, 20212022-09-300001396440main:RugDoctorLLCMember2022-09-300001396440Salient Partners L.P., Secured Debt One August 31, 20182022-09-300001396440Salient Partners L.P., Secured Debt Two September 30, 20212022-09-300001396440main:SalientPartnersLPMember2022-09-300001396440Savers, Inc., Secured Debt May 14, 20212022-09-300001396440SIB Holdings, LLC, Secured Debt One October 29, 20212022-09-300001396440SIB Holdings, LLC, Secured Debt Two October 29, 20212022-09-300001396440SIB Holdings, LLC, Secured Debt Three October 29, 20212022-09-300001396440SIB Holdings, LLC, Common Equity October 29, 20212022-09-300001396440main:SIBHoldingsLLCMember2022-09-300001396440South Coast Terminals Holdings, LLC, Secured Debt One December 10, 20212022-09-300001396440South Coast Terminals Holdings, LLC, Secured Debt Two December 10, 20212022-09-300001396440South Coast Terminals Holdings, LLC, Common Equity December 10, 20212022-09-300001396440main:SouthCoastTerminalsHoldingsLLCMember2022-09-300001396440SPAU Holdings, LLC, Secured Debt One July 01, 20222022-09-300001396440SPAU Holdings, LLC, Secured Debt Two July 01, 20222022-09-300001396440SPAU Holdings, LLC, Common Stock July 01, 20222022-09-300001396440main:SPAUHoldingsLLCMember2022-09-300001396440Staples Canada ULC, Secured Debt September 14, 20172022-09-300001396440Stellant Systems, Inc., Secured Debt October 22, 20212022-09-300001396440Student Resource Center, LLC, Secured Debt One June 15, 20212022-09-300001396440Student Resource Center, LLC, Secured Debt Two September 30, 20222022-09-300001396440Student Resource Center, LLC, Secured Debt Three September 30, 20222022-09-300001396440main:StudentResourceCenterLLCMember2022-09-300001396440Tacala Investment Corp., Secured Debt May 19, 20212022-09-300001396440Team Public Choices, LLC, Secured Debt December 22, 20202022-09-300001396440Tectonic Financial, LLC., Common Stock May 15, 20172022-09-300001396440Tex Tech Tennis, LLC., Common Stock July 07, 20212022-09-300001396440U.S. TelePacific Corp., Secured Debt May 17, 20172022-09-300001396440USA DeBusk LLC, Secured Debt October 22, 20192022-09-300001396440Veregy Consolidated, Inc., Secured Debt November 09, 20202022-09-300001396440Veregy Consolidated, Inc., Secured Debt Two November 09, 20202022-09-300001396440main:VeregyConsolidatedIncMember2022-09-300001396440Vida Capital, Inc, Secured Debt October 10, 20192022-09-300001396440Vistar Media, Inc., Preferred Stock April 03, 20192022-09-300001396440VORTEQ Coil Finishers, LLC, Secured Debt November 30, 20212022-09-300001396440VORTEQ Coil Finishers, LLC, Common Equity November 30, 20212022-09-300001396440main:VORTEQCoilFinishersLLCMember2022-09-300001396440Wahoo Fitness Acquisition L.L.C., Secured Debt August 17, 20212022-09-300001396440Wall Street Prep, Inc., Secured Debt One July 19, 20212022-09-300001396440Wall Street Prep, Inc., Secured Debt Two July 19, 20212022-09-300001396440Wall Street Prep, Inc., Common Stock July 19, 20212022-09-300001396440main:WallStreetPrepIncMember2022-09-300001396440Watterson Brands, LLC, Secured Debt One December 17, 20212022-09-300001396440Watterson Brands, LLC, Secured Debt Two December 17, 20212022-09-300001396440Watterson Brands, LLC, Secured Debt Three December 17, 20212022-09-300001396440main:WattersonBrandsLLCMember2022-09-300001396440West Star Aviation Acquisition, LLC, Secured Debt One March 01, 20222022-09-300001396440West Star Aviation Acquisition, LLC, Secured Debt Two March 01, 20222022-09-300001396440West Star Aviation Acquisition, LLC, Common Stock March 01, 20222022-09-300001396440main:WestStarAviationAcquisitionLLCMember2022-09-300001396440Winter Services LLC, Secured Debt One November 19, 20212022-09-300001396440Winter Services LLC, Secured Debt Two November 19, 20212022-09-300001396440Winter Services LLC, Secured Debt Three November 19, 20212022-09-300001396440main:WinterServicesLLCMember2022-09-300001396440Xenon Arc, Inc., Secured Debt One December 17, 20212022-09-300001396440Xenon Arc, Inc., Secured Debt Two December 17, 20212022-09-300001396440Xenon Arc, Inc., Secured Debt Three December 17, 20212022-09-300001396440main:XenonArcIncMember2022-09-300001396440YS Garments, LLC, Secured Debt August 22, 20182022-09-300001396440Zips Car Wash, LLC, Secured Debt One February 11, 20222022-09-300001396440Zips Car Wash, LLC, Secured Debt Two February 11, 20222022-09-300001396440main:ZipsCarWashLLCMember2022-09-300001396440us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2021-09-300001396440main:SecuredOvernightFinancingRateSOFROvernightIndexSwapRateOrLondonInterbankOfferedRateLIBORMembersrt:MinimumMember2022-09-300001396440main:SecuredOvernightFinancingRateSOFROvernightIndexSwapRateOrLondonInterbankOfferedRateLIBORMembersrt:MaximumMember2022-09-300001396440main:SecuredOvernightFinancingRateSOFROvernightIndexSwapRateOrLondonInterbankOfferedRateLIBORMembersrt:WeightedAverageMember2022-09-300001396440us-gaap:ForeignExchangeForwardMemberStaples Canada ULC, Secured Debt September 14, 20172022-09-30iso4217:CAD0001396440us-gaap:ForeignExchangeForwardMemberStaples Canada ULC, Secured Debt September 14, 20172022-01-012022-09-300001396440us-gaap:PrimeRateMemberArrow International, Inc, Secured Debt December 21, 20202022-09-300001396440RM Bidder, LLC., Warrants November 12, 20152021-01-012021-12-3100013964402021-01-012021-12-310001396440Channel Partners Intermediateco, LLC, Secured Debt Two February 07, 2022us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2022-09-300001396440srt:MinimumMember2022-09-300001396440srt:MaximumMember2022-09-300001396440us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMemberTacala Investment Corp., Secured Debt May 19, 20212022-09-300001396440us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMemberZips Car Wash, LLC, Secured Debt Two February 11, 20222022-09-300001396440Cadence Aerospace LLC, Secured Debt November 14, 20172022-09-300001396440us-gaap:LondonInterbankOfferedRateLIBORMemberCadence Aerospace LLC, Secured Debt November 14, 20172022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Secured Debt One August 20, 2020us-gaap:LondonInterbankOfferedRateLIBORMember2022-09-300001396440us-gaap:PrimeRateMemberIndependent Pet Partners Intermediate Holdings, LLC, Secured Debt One August 20, 20202022-09-300001396440us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMemberMB2 Dental Solutions, LLC, Secured Debt One January 28,20212022-09-300001396440Independent Pet Partners Intermediate Holdings, LLC, Warrants One November 20, 20182022-01-012022-09-300001396440Analytical Systems Keco Holdings, LLC, Secured Debt August 16,20192021-12-310001396440Analytical Systems Keco Holdings, LLC, Preferred Member Units August 16,20192021-12-310001396440Analytical Systems Keco Holdings, LLC, Preferred Member Units May 20,20212021-12-310001396440Analytical Systems Keco Holdings, LLC , Warrants August 16,20192021-12-310001396440main:AnalyticalSystemsKecoHoldingsLLCMember2021-12-310001396440ASC Interests, LLC, Secured Debt December 31,20192021-12-310001396440ASC Interests, LLC, Secured Debt August 1,20132021-12-310001396440ASC Interests, LLC, Member Units August 1,20132021-12-310001396440main:ASCInterestsLLCMember2021-12-310001396440ATS Workholding, LLC, Secured Debt November 16,20172021-12-310001396440ATS Workholding, LLC, Preferred Member Units November 16,20172021-12-310001396440main:ATSWorkholdingLLCMember2021-12-310001396440Barfly Ventures, LLC, Secured Debt October 15,20202021-12-310001396440Barfly Ventures, LLC, Member Units October 26,20202021-12-310001396440main:BarflyVenturesLLCMember2021-12-310001396440Bolder Panther Group, LLC, Secured Debt December 31,20202021-12-310001396440Bolder Panther Group, LLC, Class A Preferred Member Units December 31,20202021-12-310001396440Bolder Panther Group, LLC, Class B Preferred Member Units December 31,20202021-12-310001396440main:BolderPantherGroupLLCMember2021-12-310001396440Brewer Crane Holdings, LLC, Secured Debt January 09,20182021-12-310001396440Brewer Crane Holdings, LLC, Preferred Member Units January 09,20182021-12-310001396440main:BrewerCraneHoldingsLLCMember2021-12-310001396440Bridge Capital Solutions Corporation, Secured Debt July 25,20162021-12-310001396440Bridge Capital Solutions Corporation, Warrants July 25,20162021-12-310001396440Bridge Capital Solutions Corporation, Secured Debt July 25, 20162021-12-310001396440Bridge Capital Solutions Corporation, Preferred Member Units July 25,20162021-12-310001396440main:BridgeCapitalSolutionsCorporationMember2021-12-310001396440Café Brazil, LLC, Member Units June 09,20062021-12-310001396440California Splendor Holdings LLC, Secured Debt March 30,20182021-12-310001396440California Splendor Holdings LLC, Preferred Member Units July 31,20192021-12-310001396440California Splendor Holdings LLC, Preferred Member Units March 30,20182021-12-310001396440main:CaliforniaSplendorHoldingsLLCMember2021-12-310001396440CBT Nuggets, LLC, Member Units June 01,20062021-12-310001396440Centre Technologies Holdings, LLC, Secured Debt January 04,20192021-12-310001396440Centre Technologies Holdings, LLC, Preferred Member Units January 04,20192021-12-310001396440main:CentreTechnologiesHoldingsLLCMember2021-12-310001396440Chamberlin Holding LLC, Secured Debt February 26,20182021-12-310001396440Chamberlin Holding LLC, Member Units February 26,20182021-12-310001396440Chamberlin Holding LLC, Member Units November 2, 20182021-12-310001396440main:ChamberlinHoldingLLCMember2021-12-310001396440Charps, LLC, Unsecured Debt February 26,20182021-12-310001396440Charps, LLC, Preferred Member Units February 03,20172021-12-310001396440main:CharpsLLCMember2021-12-310001396440Clad-Rex Steel, LLC, Secured Debt One December 20,20162021-12-310001396440Clad-Rex Steel, LLC, Member Units One December 20,20162021-12-310001396440Clad-Rex Steel, LLC, Secured Debt Two December 20,20162021-12-310001396440Clad-Rex Steel, LLC, Member Units Two December 20,20162021-12-310001396440main:CladRexSteelLLCMember2021-12-310001396440CMS Minerals Investments, Member Units April 01,20162021-12-310001396440Cody Pools, Inc., Secured Debt March 06,20202021-12-310001396440Cody Pools, Inc., Preferred Member Units March 06,20202021-12-310001396440main:CodyPoolsIncMember2021-12-310001396440Colonial Electric Company LLC, Secured Debt March 31,20212021-12-310001396440Colonial Electric Company LLC, Preferred Member Units March 31,20212021-12-310001396440main:ColonialElectricCompanyLLCMember2021-12-310001396440CompareNetworks Topco, LLC, Secured Debt January 29,20192021-12-310001396440CompareNetworks Topco, LLC, Preferred Member Units January 29,20192021-12-310001396440main:CompareNetworksTopcoLLCMember2021-12-310001396440Copper Trail Fund Investments, LP Interests (CTMH, LP) July 17,20172021-12-310001396440Datacom, LLC, Secured Debt March 31,20212021-12-310001396440Datacom, LLC, Preferred Member Units March 31,20212021-12-310001396440main:DatacomLLCMember2021-12-310001396440Digital Products Holdings LLC, Secured Debt January 29,20192021-12-310001396440Digital Products Holdings LLC, Preferred Member Units April 01,20182021-12-310001396440main:DigitalProductsHoldingsLLCMember2021-12-310001396440Direct Marketing Solutions, Inc., Secured Debt February 13,20182021-12-310001396440Direct Marketing Solutions, Inc., Preferred Stock February 13,20182021-12-310001396440main:DirectMarketingSolutionsIncMember2021-12-310001396440Gamber-Johnson Holdings, LLC, Secured Debt June 24,20162021-12-310001396440Gamber-Johnson Holdings, LLC, Member Units June 24,20162021-12-310001396440main:GamberJohnsonHoldingsLLCMember2021-12-310001396440Garreco, LLC, Secured Debt July 15,20132021-12-310001396440Garreco, LLC, Member Units July 15,20132021-12-310001396440main:GarrecoLLCMember2021-12-310001396440GRT Rubber Technologies LLC, Secured Debt December 19,20142021-12-310001396440GRT Rubber Technologies LLC, Member Units December 19,20142021-12-310001396440main:GRTRubberTechnologiesLLCMember2021-12-310001396440Gulf Manufacturing, LLC, Member Units August 31,20072021-12-310001396440Gulf Publishing Holdings, LLC, Secured Debt September 29,20172021-12-310001396440Gulf Publishing Holdings, LLC, Secured Debt April 29, 20162021-12-310001396440Gulf Publishing Holdings, LLC, Member Units April 29,20162021-12-310001396440main:GulfPublishingHoldingsLLCMember2021-12-310001396440Harris Preston Fund Investments, LP Interests (2717 MH, L.P.) October 1,20072021-12-310001396440Harrison Hydra-Gen, Ltd., Common Stock June 04,20102021-12-310001396440Jensen Jewelers of Idaho, LLC, Secured Debt November 14,20062021-12-310001396440Jensen Jewelers of Idaho, LLC, Member Units November 14,20062021-12-310001396440main:JensenJewelersOfIdahoLLCMember2021-12-310001396440Johnson Downie Opco, LLC, Secured Debt December 10,20212021-12-310001396440Johnson Downie Opco, LLC, Preferred Equity December 10,20212021-12-310001396440main:JohnsonDownieOpcoLLCMember2021-12-310001396440KBK Industries, LLC, Member Units January 23, 20062021-12-310001396440Kickhaefer Manufacturing Company, LLC, Secured Debt One October 31,20182021-12-310001396440Kickhaefer Manufacturing Company, LLC, Member Units One October 31,20182021-12-310001396440Kickhaefer Manufacturing Company, LLC, Secured Debt Two October 31,20182021-12-310001396440Kickhaefer Manufacturing Company, LLC, Member Units Two October 31,20182021-12-310001396440main:KickhaeferManufacturingCompanyLLCMember2021-12-310001396440Market Force Information, LLC, Secured Debt One July 28,20172021-12-310001396440Market Force Information, LLC, Secured Debt Two July 28,20172021-12-310001396440Market Force Information, LLC, Member Units July 28,20172021-12-310001396440main:MarketForceInformationLLCMember2021-12-310001396440MH Corbin Holding LLC, Secured Debt August 31,20152021-12-310001396440MH Corbin Holding LLC, Preferred Member Units March 15,20192021-12-310001396440MH Corbin Holding LLC, Preferred Member Units September 01,20152021-12-310001396440main:MHCorbinHoldingLLCMember2021-12-310001396440MS Private Loan Fund I, LP, Unsecured Debt February 11,20212021-12-310001396440MS Private Loan Fund I, LP, LP Interests January 26,20212021-12-310001396440main:MSPrivateLoanFundILPMember2021-12-310001396440MSC Adviser I, LLC, Member Units November 22,20132021-12-310001396440Mystic Logistics Holdings, LLC, Secured Debt August 18,20142021-12-310001396440Mystic Logistics Holdings, LLC, Common Stock August 18,20142021-12-310001396440main:MysticLogisticsHoldingsLLCMember2021-12-310001396440NAPCO Precast, LLC, Member Units January 31,20082021-12-310001396440Nebraska Vet AcquireCo, LLC, Secured Debt One December 31,20202021-12-310001396440Nebraska Vet AcquireCo, LLC, Secured Debt Two December 31,20202021-12-310001396440Nebraska Vet AcquireCo, LLC, Preferred Member Units December 31,20202021-12-310001396440main:NebraskaVetAcquireCoLLCMember2021-12-310001396440NexRev LLC, Secured Debt February 28,20182021-12-310001396440NexRev LLC, Preferred Member Units February 28,20182021-12-310001396440main:NexRevLLCMember2021-12-310001396440NRP Jones, LLC, Secured Debt December 21,20172021-12-310001396440NRP Jones, LLC, Member Units December 22,20112021-12-310001396440main:NRPJonesLLCMember2021-12-310001396440NuStep, LLC, Secured Debt One January 31,20172021-12-310001396440NuStep, LLC, Secured Debt Two January 31,20172021-12-310001396440NuStep, LLC, Preferred Member Units January 31,20172021-12-310001396440main:NuStepLLCMember2021-12-310001396440OMi Topco, LLC, Secured Debt August 31,20212021-12-310001396440OMi Topco, LLC, Preferred Member Units April 01,20082021-12-310001396440main:OMiTopcoLLCMember2021-12-310001396440Orttech Holdings, LLC, Secured Debt July 30,20212021-12-310001396440Orttech Holdings, LLC, Preferred Stock July 30,20212021-12-310001396440main:OrttechHoldingsLLCMember2021-12-310001396440Pearl Meyer Topco LLC, Secured Debt April 27,20202021-12-310001396440Pearl Meyer Topco LLC, Member Units April 27,20202021-12-310001396440main:PearlMeyerTopcoLLCMember2021-12-310001396440PPL RVs, Inc., Secured Debt October 31,20192021-12-310001396440PPL RVs, Inc., Secured Debt November 15,20162021-12-310001396440PPL RVs, Inc.,Common Stock June 10,20102021-12-310001396440main:PPLRVsIncMember2021-12-310001396440Principle Environmental, LLC, Secured Debt February 01,20112021-12-310001396440Principle Environmental, LLC, Secured Debt July 01,20112021-12-310001396440Principle Environmental, LLC, Preferred Member Units February 01,20112021-12-310001396440Principle Environmental, LLC, Common Stock January 27,20212021-12-310001396440main:PrincipleEnvironmentalLLCMember2021-12-310001396440Quality Lease Service, LLC, Member Units June 08,20152021-12-310001396440River Aggregates, LLC, Member Units December 20,20132021-12-310001396440Robbins Bros. Jewelry, Inc., Secured Debt December 15,20212021-12-310001396440Robbins Bros. Jewelry, Inc., Preferred Equity December 15,20212021-12-310001396440main:RobbinsBrosJewelryIncMember2021-12-310001396440Tedder Industries, LLC, Secured Debt August 31,20182021-12-310001396440Tedder Industries, LLC, Preferred Member Units August 31,20182021-12-310001396440main:TedderIndustriesLLCMember2021-12-310001396440Televerde, LLC, Member Units January 06,20112021-12-310001396440Trantech Radiator Topco, LLC, Secured Debt May 31,20192021-12-310001396440Trantech Radiator Topco, LLC, Common Stock May 31,20192021-12-310001396440main:TrantechRadiatorTopcoLLCMember2021-12-310001396440UnionRock Energy Fund II, LP, LP Interests June 15,20202021-12-310001396440Vision Interests, Inc., Series A Preferred Stock December 23,20112021-12-310001396440VVS Holdco LLC, Secured Debt One December 01,20212021-12-310001396440VVS Holdco LLC, Secured Debt Two December 01,20212021-12-310001396440VVS Holdco LLC, Preferred Equity December 01,20212021-12-310001396440main:VVSHoldcoLLCMember2021-12-310001396440Ziegler’s NYPD, LLC, Secured Debt June 01,20152021-12-310001396440Ziegler’s NYPD, LLC, Secured Debt One October 01,20082021-12-310001396440Ziegler’s NYPD, LLC, Secured Debt Two October 01,20082021-12-310001396440Ziegler’s NYPD, LLC, Preferred Member Units June 30,20152021-12-310001396440Ziegler’s NYPD, LLC, Warrants July 01,20152021-12-310001396440main:ZieglersNYPDLLCMember2021-12-310001396440AAC Holdings, Inc., Secured Debt December 11,20202021-12-310001396440AAC Holdings, Inc., Common Stock December 11,20202021-12-310001396440AAC Holdings, Inc., Warrants December 11,20202021-12-310001396440main:AACHoldingsIncMember2021-12-310001396440AFG Capital Group, LLC, Secured Debt April 25,20192021-12-310001396440AFG Capital Group, LLC, Preferred Member Units November 07,20142021-12-310001396440main:AFGCapitalGroupLLCMember2021-12-310001396440ATX Networks Corp., Secured Debt September 01,20212021-12-310001396440ATX Networks Corp., Unsecured Debt September 01,20212021-12-310001396440ATX Networks Corp., Common Stock September 01,20212021-12-310001396440main:ATXNetworksCorpMember2021-12-310001396440BBB Tank Services, LLC, Unsecured Debt April 08,20162021-12-310001396440BBB Tank Services, LLC, Preferred Stock (non-voting) December 17,20182021-12-310001396440BBB Tank Services, LLC, Member Units April 08,20162021-12-310001396440main:BBBTankServicesLLCMember2021-12-310001396440Boccella Precast Products LLC, Secured Debt September 23,20212021-12-310001396440Boccella Precast Products LLC, Member Units June 30,20172021-12-310001396440main:BoccellaPrecastProductsLLCMember2021-12-310001396440Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund V, LP) July 12,20212021-12-310001396440Buca C, LLC, Secured Debt June 30,20152021-12-310001396440Buca C, LLC, Preferred Member Units June 30,20152021-12-310001396440main:BucaCLLCMember2021-12-310001396440Career Team Holdings, LLC, Secured Debt December 17,20212021-12-310001396440Career Team Holdings, LLC, Class A Common Units December 17,20212021-12-310001396440main:CareerTeamHoldingsLLCMember2021-12-310001396440Chandler Signs Holdings, LLC, Class A Units January 04,20162021-12-310001396440Classic H&G Holdings, LLC, Secured Debt One March 12,20202021-12-310001396440Classic H&G Holdings, LLC, Secured Debt Two March 12,20202021-12-310001396440Classic H&G Holdings, LLC, Preferred Member Units March 12,20202021-12-310001396440main:ClassicHGHoldingsLLCMember2021-12-310001396440Congruent Credit Opportunities Funds, LP Interests (Congruent Credit Opportunities Fund III, LP) February 04,20152021-12-310001396440DMA Industries, LLC, Secured Debt November 30,20152021-12-310001396440DMA Industries, LLC, Preferred Equity November 30,20152021-12-310001396440main:DMAIndustriesLLCMember2021-12-310001396440Dos Rios Partners, LP Interests (Dos Rios Partners, LP) April 25,20132021-12-310001396440Dos Rios Partners, LP Interests (Dos Rios Partners - A, LP) April 25,20132021-12-310001396440main:DosRiosPartnersMember2021-12-310001396440Dos Rios Stone Products LLC, Class A Preferred Units June 27,20162021-12-310001396440EIG Fund Investments, LP Interests (EIG Global Private Debt Fund-A, L.P.) November 06,20152021-12-310001396440Flame King Holdings, LLC, Secured Debt One October 29,20212021-12-310001396440Flame King Holdings, LLC, Secured Debt Two October 29,20212021-12-310001396440Flame King Holdings, LLC, Preferred Equity October 29,20212021-12-310001396440main:FlameKingHoldingsLLCMember2021-12-310001396440Freeport Financial Funds, LP Interests (Freeport Financial SBIC Fund LP) March 23,20152021-12-310001396440Freeport Financial Funds, LP Interests (Freeport First Lien Loan Fund III LP) July 31,20152021-12-310001396440main:FreeportFinancialFundsMember2021-12-310001396440GFG Group, LLC., Secured Debt March 31,20212021-12-310001396440GFG Group, LLC., Preferred Member Units March 31,20212021-12-310001396440main:GFGGroupLLCMember2021-12-310001396440Harris Preston Fund Investments, LP Interests (HPEP 3, L.P.) August 09,20172021-12-310001396440Hawk Ridge Systems, LLC, Secured Debt One December 02,20162021-12-310001396440Hawk Ridge Systems, LLC, Secured Debt Two December 02,20162021-12-310001396440Hawk Ridge Systems, LLC, Preferred Member Units One December 02,20162021-12-310001396440Hawk Ridge Systems, LLC, Preferred Member Units Two December 02,20162021-12-310001396440main:HawkRidgeSystemsLLCMember2021-12-310001396440Houston Plating and Coatings, LLC, Unsecured Convertible Debt May 01,20172021-12-310001396440Houston Plating and Coatings, LLC, Member Units January 08,20032021-12-310001396440main:HoustonPlatingAndCoatingsLLCMember2021-12-310001396440I-45 SLF LLC, Member Units (Fully diluted 20.0%; 24.40% profits interest) (8) October 20,20152021-12-310001396440Iron-Main Investments, LLC, Secured Debt One August 03,20212021-12-310001396440Iron-Main Investments, LLC, Secured Debt September 01,20212021-12-310001396440Iron-Main Investments, LLC, Secured Debt Two August 03,20212021-12-310001396440Iron-Main Investments, LLC, Secured Debt Three August 03,20212021-12-310001396440Iron-Main Investments, LLC, Common Stock August 03,20212021-12-310001396440main:IronMainInvestmentsLLCMember2021-12-310001396440L.F. Manufacturing Holdings, LLC, Preferred Member Units (non-voting) January 01,20192021-12-310001396440L.F. Manufacturing Holdings, LLC, Member Units December 23,20132021-12-310001396440main:LFManufacturingHoldingsLLCMember2021-12-310001396440OnAsset Intelligence, Inc., Secured Debt May 20,20142021-12-310001396440OnAsset Intelligence, Inc., Secured Debt March 21,20142021-12-310001396440OnAsset Intelligence, Inc., Secured Debt May 10,20132021-12-310001396440OnAsset Intelligence, Inc., Secured Debt April 18,20112021-12-310001396440OnAsset Intelligence, Inc., Unsecured Debt June 05,20172021-12-310001396440OnAsset Intelligence, Inc., Preferred Stock April 18,20112021-12-310001396440OnAsset Intelligence, Inc., Common Stock April 15,20212021-12-310001396440OnAsset Intelligence, Inc., Warrants April 18,20112021-12-310001396440main:OnAssetIntelligenceIncMember2021-12-310001396440Oneliance, LLC, Secured Debt August 06,20212021-12-310001396440Oneliance, LLC, Preferred Stock August 06,20212021-12-310001396440main:OnelianceLLCMember2021-12-310001396440Rocaceia, LLC (Quality Lease and Rental Holdings, LLC), Secured Debt June 30,20152021-12-310001396440Rocaceia, LLC (Quality Lease and Rental Holdings, LLC), Preferred Member Units January 08,20132021-12-310001396440main:RocaceiaLLCQualityLeaseAndRentalHoldingsLLCMember2021-12-310001396440SI East, LLC, Secured Debt August 31,20182021-12-310001396440SI East, LLC, Preferred Member Units August 31,20182021-12-310001396440main:SIEastLLCMember2021-12-310001396440Slick Innovations, LLC, Secured Debt September 13,20182021-12-310001396440Slick Innovations, LLC, Common Stock September 13,20182021-12-310001396440Slick Innovations, LLC, Warrants September 13,20182021-12-310001396440main:SlickInnovationsLLCMember2021-12-310001396440Sonic Systems International, LLC, Secured Debt August 20,20212021-12-310001396440Sonic Systems International, LLC, Common Stock August 20,20212021-12-310001396440main:SonicSystemsInternationalLLCMember2021-12-310001396440Superior Rigging & Erecting Co., Secured Debt August 31,20202021-12-310001396440Superior Rigging & Erecting Co., Preferred Member Units August 31,20202021-12-310001396440main:SuperiorRiggingErectingCoMember2021-12-310001396440The Affiliati Network, LLC, Secured Debt August 09,20212021-12-310001396440The Affiliati Network, LLC, Secured Debt One August 09,20212021-12-310001396440The Affiliati Network, LLC, Preferred Stock August 09,20212021-12-310001396440main:TheAffiliatiNetworkLLCMember2021-12-310001396440UniTek Global Services, Inc., Secured Debt October 15,20182021-12-310001396440UniTek Global Services, Inc., Secured Debt August 27,20182021-12-310001396440UniTek Global Services, Inc., Secured Convertible Debt January 01,20212021-12-310001396440UniTek Global Services, Inc., Preferred Stock August 29,20192021-12-310001396440UniTek Global Services, Inc., Preferred Stock August 21,20182021-12-310001396440UniTek Global Services, Inc., Preferred Stock January 15,20152021-12-310001396440UniTek Global Services, Inc., Preferred Stock June 30,20172021-12-310001396440UniTek Global Services, Inc., Common Stock April 01,20202021-12-310001396440main:UniTekGlobalServicesIncMember2021-12-310001396440Universal Wellhead Services Holdings, LLC, Preferred Member Units December 07,20162021-12-310001396440Universal Wellhead Services Holdings, LLC, Member Units December 07,20162021-12-310001396440main:UniversalWellheadServicesHoldingsLLCMember2021-12-310001396440Volusion, LLC, Secured Debt January 26,20152021-12-310001396440Volusion, LLC, Unsecured Convertible Debt May 16,20182021-12-310001396440Volusion, LLC, Preferred Member Units January 26,20152021-12-310001396440Volusion, LLC, Warrants January 26,20152021-12-310001396440main:VolusionLLCMember2021-12-310001396440Acousti Engineering Company of Florida, Secured Debt November 02,20202021-12-310001396440Acousti Engineering Company of Florida, Secured Debt May 26,20212021-12-310001396440main:AcoustiEngineeringCompanyOfFloridaMember2021-12-310001396440ADS Tactical, Inc., Secured Debt March 29,20212021-12-310001396440American Health Staffing Group, Inc., Secured Debt November 19,20212021-12-310001396440American Nuts, LLC, Secured Debt December 21,20182021-12-310001396440American Teleconferencing Services, Ltd., Secured Debt September 17,20212021-12-310001396440American Teleconferencing Services, Ltd., Secured Debt May 19,20162021-12-310001396440main:AmericanTeleconferencingServicesLtdMember2021-12-310001396440ArborWorks, LLC, Secured Debt November 09,20212021-12-310001396440ArborWorks, LLC, Common Equity November 09,20212021-12-310001396440main:ArborWorksLLCMember2021-12-310001396440Arrow International, Inc, Secured Debt December 21,20202021-12-310001396440AVEX Aviation Holdings, LLC, Secured Debt December 15,20212021-12-310001396440AVEX Aviation Holdings, LLC, Common Equity December 15,20212021-12-310001396440main:AVEXAviationHoldingsLLCMember2021-12-310001396440Berry Aviation, Inc., Secured Debt July 06,20182021-12-310001396440Berry Aviation, Inc., Preferred Member Units November 12,20192021-12-310001396440Berry Aviation, Inc., Preferred Member Units July 06,20182021-12-310001396440main:BerryAviationIncMember2021-12-310001396440Binswanger Enterprises, LLC, Secured Debt March 10,20172021-12-310001396440Binswanger Enterprises, LLC, Member Units March 10,20172021-12-310001396440main:BinswangerEnterprisesLLCMember2021-12-310001396440Bluestem Brands, Inc., Secured Debt August 28,20202021-12-310001396440Bluestem Brands, Inc., Common Stock October 01,20202021-12-310001396440main:BluestemBrandsIncMember2021-12-310001396440Brainworks Software, LLC, Secured Debt August 12,20142021-12-310001396440Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund III, LP) July 21,20142021-12-310001396440Brightwood Capital Fund Investments, LP Interests (Brightwood Capital Fund IV, LP) October 26,20162021-12-310001396440main:BrightwoodCapitalFundInvestmentsMember2021-12-310001396440Burning Glass Intermediate Holding Company, Inc., Secured Debt June 14,20212021-12-310001396440Burning Glass Intermediate Holding Company, Inc., Secured Debt One June 14,20212021-12-310001396440main:BurningGlassIntermediateHoldingCompanyIncMember2021-12-310001396440Cadence Aerospace LLC, Secured Debt November 14,20172021-12-310001396440CAI Software LLC, Preferred Equity One December 13,20212021-12-310001396440CAI Software LLC, Preferred Equity Two December 13,20212021-12-310001396440main:CAISoftwareLLCMember2021-12-310001396440Camin Cargo Control, Inc., Secured Debt June 14,20212021-12-310001396440Cenveo Corporation, Common Stock September 07,20182021-12-310001396440Chisholm Energy Holdings, LLC, Secured Debt May 15,20192021-12-310001396440Clarius BIGS, LLC, Secured Debt September 23,20142021-12-310001396440Computer Data Source, LLC, Secured Debt August 06,20212021-12-310001396440Construction Supply Investments, LLC, Member Units December 29,20162021-12-310001396440Darr Equipment LP, Secured Debt December 26,20172021-12-310001396440Darr Equipment LP, Warrants April 15,20142021-12-310001396440main:DarrEquipmentLPMember2021-12-310001396440DTE Enterprises, LLC, Secured Debt April 13,20182021-12-310001396440DTE Enterprises, LLC, Class AA Preferred Member Units (non-voting) April 13,20182021-12-310001396440DTE Enterprises, LLC, Class A Preferred Member Units April 13,20182021-12-310001396440main:DTEEnterprisesLLCMember2021-12-310001396440Dynamic Communities, LLC, Secured Debt July 17,20182021-12-310001396440Eastern Wholesale Fence LLC, Secured Debt November 19,20202021-12-310001396440EnCap Energy Fund Investments, LP Interests (EnCap Energy Capital Fund VIII, L.P.) January 22,20152021-12-310001396440EnCap Energy Fund Investments, LP Interests (EnCap Energy Capital Fund VIII Co- Investors, L.P.) January 21,20152021-12-310001396440EnCap Energy Fund Investments, LP Interests (EnCap Energy Capital Fund IX, L.P.) January 22,20152021-12-310001396440EnCap Energy Fund Investments, LP Interests (EnCap Energy Capital Fund X, L.P.) March 25,20152021-12-310001396440EnCap Energy Fund Investments, LP Interests (EnCap Flatrock Midstream Fund II, L.P.) March 30,20152021-12-310001396440EnCap Energy Fund Investments, LP Interests (EnCap Flatrock Midstream Fund III, L.P.) March 27,20152021-12-310001396440main:EnCapEnergyFundInvestmentsMember2021-12-310001396440EPIC Y-Grade Services, LP, Secured Debt June 22,20182021-12-310001396440Event Holdco, LLC, Secured Debt December 22,20212021-12-310001396440Flip Electronics LLC, Secured Debt January 04,20212021-12-310001396440Fortna Acquisition Co., Inc., Secured Debt July 23,20192021-12-310001396440Fuse, LLC, Secured Debt June 30,20192021-12-310001396440Fuse, LLC, Common Stock June 30,20192021-12-310001396440main:FuseLLCMember2021-12-310001396440GeoStabilization International (GSI), Secured Debt January 02,20192021-12-310001396440GoWireless Holdings, Inc., Secured Debt January 10,20182021-12-310001396440Grupo Hima San Pablo, Inc., Secured Debt March 07,20132021-12-310001396440Grupo Hima San Pablo, Inc., Secured Debt One March 07,20132021-12-310001396440Grupo Hima San Pablo, Inc., Secured Debt Two March 07,20132021-12-310001396440main:GrupoHimaSanPabloIncMember2021-12-310001396440GS HVAM Intermediate, LLC, Secured Debt October 18,20192021-12-310001396440GS Operating, LLC, Secured Debt February 24,20202021-12-310001396440HDC/HW Intermediate Holdings, Secured Debt December 21,20182021-12-310001396440Heartland Dental, LLC, Secured Debt September 09,20202021-12-310001396440HOWLCO LLC, Secured Debt August 19,20212021-12-310001396440Hybrid Promotions, LLC, Secured Debt June 30,20212021-12-310001396440IG Parent Corporation, Secured Debt July 30,20212021-12-310001396440Implus Footcare, LLC, Secured Debt June 01,20172021-12-310001396440Independent Pet Partners Intermediate Holdings, LLC, Secured Debt August 20,20202021-12-310001396440Independent Pet Partners Intermediate Holdings, LLC, Secured Debt December 10,20202021-12-310001396440Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) One December 10,20202021-12-310001396440Independent Pet Partners Intermediate Holdings, LLC, Preferred Stock (non-voting) Two December 10,20202021-12-310001396440Independent Pet Partners Intermediate Holdings, LLC, Member Units November 20,20182021-12-310001396440main:IndependentPetPartnersIntermediateHoldingsLLCMember2021-12-310001396440Industrial Services Acquisition, LLC, Secured Debt August 13,20212021-12-310001396440Industrial Services Acquisition, LLC, Preferred Member Units January 31,20182021-12-310001396440Industrial Services Acquisition, LLC, Preferred Member Units May 17,20192021-12-310001396440Industrial Services Acquisition, LLC, Member Units June 17,20162021-12-310001396440main:IndustrialServicesAcquisitionLLCMember2021-12-310001396440Infolinks Media Buyco, LLC, Secured Debt November 01,20212021-12-310001396440Interface Security Systems, L.L.C, Secured Debt December 09,20212021-12-310001396440Interface Security Systems, L.L.C, Secured Debt August 07,20192021-12-310001396440main:InterfaceSecuritySystemsLLCMember2021-12-310001396440Intermedia Holdings, Inc., Secured Debt August 03,20182021-12-310001396440Invincible Boat Company, LLC., Secured Debt August 28,20192021-12-310001396440INW Manufacturing, LLC, Secured Debt May 19,20212021-12-310001396440Isagenix International, LLC, Secured Debt June 21,20182021-12-310001396440Jackmont Hospitality, Inc., Secured Debt May 26,20152021-12-310001396440Jackmont Hospitality, Inc., Preferred Equity November 08,20212021-12-310001396440main:JackmontHospitalityIncMember2021-12-310001396440Joerns Healthcare, LLC, Secured Debt August 21,20192021-12-310001396440Joerns Healthcare, LLC, Secured Debt November 15,20212021-12-310001396440Joerns Healthcare, LLC, Common Stock August 21,20192021-12-310001396440main:JoernsHealthcareLLCMember2021-12-310001396440JTI Electrical & Mechanical, LLC, Secured Debt December 22,20212021-12-310001396440JTI Electrical & Mechanical, LLC, Common Equity December 22,20212021-12-310001396440main:JTIElectricalMechanicalLLCMember2021-12-310001396440Klein Hersh, LLC, Secured Debt November 13,20202021-12-310001396440KMS, LLC, Secured Debt October 04,20212021-12-310001396440Kore 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Capital Fund V, LPus-gaap:EquitySecuritiesMember2022-09-300001396440Brightwood Capital Fund III, LPus-gaap:EquitySecuritiesMember2022-09-300001396440main:BrightwoodCapitalFundInvestmentsMemberus-gaap:EquitySecuritiesMember2022-09-300001396440Freeport First Lien Loan Fund III LPus-gaap:EquitySecuritiesMember2022-09-300001396440Freeport Financial SBIC Fund LPus-gaap:EquitySecuritiesMember2022-09-300001396440main:FreeportFundInvestmentsMemberus-gaap:EquitySecuritiesMember2022-09-300001396440us-gaap:EquitySecuritiesMemberHPEP 4, L.P.2022-09-300001396440HPEP 3, L.P.us-gaap:EquitySecuritiesMember2022-09-300001396440HPEP 423 COR, LPus-gaap:EquitySecuritiesMember2022-09-3000013964402717 HPP-MS, LPus-gaap:EquitySecuritiesMember2022-09-300001396440main:HarrisPrestonFundInvestmentsMemberus-gaap:EquitySecuritiesMember2022-09-300001396440MS Private Loan Fund I, LPus-gaap:EquitySecuritiesMember2022-09-300001396440UnionRock Energy Fund II, LPus-gaap:EquitySecuritiesMember2022-09-300001396440us-gaap:EquitySecuritiesMember2022-09-300001396440Xenon Arc, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440Dalton US Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440CaseWorthy, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440HEADLANDS OP-CO LLCus-gaap:DebtSecuritiesMember2022-09-300001396440MS Private Loan Fund I, LPus-gaap:DebtSecuritiesMember2022-09-300001396440PTL US Bidco, Incus-gaap:DebtSecuritiesMember2022-09-300001396440JTI Electrical & Mechanical, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440AMEREQUIP LLC.us-gaap:DebtSecuritiesMember2022-09-300001396440NinjaTrader, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Paragon Healthcare, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440Archer Systems, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Veregy Consolidated, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440SI East, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Watterson Brands, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Bolder Panther Group, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Pearl Meyer Topco LLCus-gaap:DebtSecuritiesMember2022-09-300001396440NWN Corporationus-gaap:DebtSecuritiesMember2022-09-300001396440Robbins Bros. Jewelry, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440South Coast Terminals Holdings, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440AB Centers Acquisition Corporationus-gaap:DebtSecuritiesMember2022-09-300001396440Winter Services LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Adams Publishing Group, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Bettercloud, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440MonitorUS Holding, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Microbe Formulas, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440MB2 Dental Solutions, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440GRT Rubber Technologies LLCus-gaap:DebtSecuritiesMember2022-09-300001396440SPAU Holdings, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Cody Pools, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440AVEX Aviation Holdings, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Batjer TopCo, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440GULF PACIFIC ACQUISITION, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Infolinks Media Buyco, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Engineering Research & Consulting, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Nebraska Vet AcquireCo, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Mako Steel, LPus-gaap:DebtSecuritiesMember2022-09-300001396440West Star Aviation Acquisition, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440VVS Holdco, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Centre Technologies Holdings, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440IG Parent Corporationus-gaap:DebtSecuritiesMember2022-09-300001396440PPL RVs, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440The Affiliati Network, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440us-gaap:DebtSecuritiesMemberEvergreen North America Acquisitions, LLC2022-09-300001396440us-gaap:DebtSecuritiesMemberATS Operating, LLC2022-09-300001396440Career Team Acquireco LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Johnson Downie Opco, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Burning Glass Intermediate Holding Company, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440Chamberlin Holding LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Colonial Electric Company LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Trantech Radiator Topco, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Roof Opco, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440American Health Staffing Group, Inc.us-gaap:DebtSecuritiesMember2022-09-300001396440RA Outdoors LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Project Eagle Holdings, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440Gamber-Johnson Holdings, LLCus-gaap:DebtSecuritiesMember2022-09-300001396440KMS, LLC