http://sixthstreetspecialtylending.com/20221231#NetRealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslation0001508655http://fasb.org/us-gaap/2022#AccountingStandardsUpdate202006Memberhttp://fasb.org/us-gaap/2022#AccountingStandardsUpdate202006Memberhttp://sixthstreetspecialtylending.com/20221231#NetRealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationFYfalsehttp://sixthstreetspecialtylending.com/20221231#NetChangeInUnrealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://fasb.org/us-gaap/2022#UnrealizedGainLossOnDerivativeshttp://sixthstreetspecialtylending.com/20221231#NetChangeInUnrealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslation0001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:CordanceOperationsLlcMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:HomecareSoftwareSolutionsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:HealthcareSectorMember2021-01-012021-12-310001508655tslx:StructuredCreditMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:DelayedDrawMembertslx:AxonifyIncMember2021-12-310001508655us-gaap:FinancialServicesSectorMembertslx:PingIdentityHoldingCorporationMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyNineMember2022-01-012022-12-310001508655tslx:WideOrbitIncMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentyFiveMembertslx:BusinessServicesMember2022-01-012022-12-310001508655tslx:DyeDurhamLtdMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:SeriesFPreferredStockMembertslx:LucidworksIncMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:OctagonInvestmentPartnersThirtyEightLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:AlphaMidcoIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-310001508655us-gaap:SeriesDPreferredStockMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2022-01-012022-12-310001508655tslx:EMSLinqIncMembertslx:EducationMembertslx:ClassBUnitsMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMembertslx:ManufacturingMemberus-gaap:DebtSecuritiesMembertslx:AvalaraIncMember2022-12-310001508655tslx:InterestRateSwapTenMember2022-01-012022-12-3100015086552022-04-012022-06-300001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixOneMembertslx:BankBillSwapBidRateMembertslx:HumanResourceSupportServicesMembertslx:EmploymentHeroHoldingsPtyLtdMember2021-12-310001508655tslx:LucidworksIncMemberus-gaap:SeriesFPreferredStockMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:BaseDividendMember2021-05-040001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:MerativeLPMemberus-gaap:HealthcareSectorMembertslx:FirstLienLoanDueJuneTwoThousandTwentyEightMember2022-01-012022-12-310001508655tslx:AmericanAchievementCorpMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveOneMember2021-01-012021-12-310001508655tslx:WestMember2022-12-310001508655tslx:InterestRateSwapTwoMember2022-01-012022-12-310001508655tslx:SupplementalDividendMember2021-11-022021-11-020001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:BtrsHoldingsIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyEightMember2022-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:EDBParentLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMembertslx:BlueSnapIncMember2021-12-310001508655tslx:ValidityIncMemberus-gaap:SeriesAPreferredStockMembertslx:MarketingServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SpecialDividendMember2020-02-190001508655tslx:StructuredCreditMembertslx:DrydenSeniorLoanFundSeriesTwoThousandEighteenFiftyFiveAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655srt:PartnershipInterestMembertslx:EducationMembertslx:RMCFIVCIVXXXVLPMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:WorkwellAcquisitionCoMember2021-12-310001508655tslx:DaySmartHoldingsLLCMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2022-01-012022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2013-01-012013-12-310001508655tslx:FirstLienNoteDueJuneTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:MarketingServicesMembertslx:AcousticLPMember2021-01-012021-12-310001508655tslx:WindRiverCloLtdSeriesTwoThousandEighteenThreeAMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:BenefitStreetPartnersCloLtdSeriesTwoThousandFifteenBRMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapMember2021-12-310001508655tslx:TwoThousandTwentyFourNotesMember2022-12-310001508655tslx:FirstLienLoanDueAugustTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-310001508655tslx:FirstLienLoanDueMarchTwoThousandTwentySixMembertslx:OmnigoSoftwareLLCMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:OtherMember2022-12-310001508655tslx:EmploymentHeroHoldingsPtyLtdMembertslx:DelayedDrawAndRevolverMember2021-12-310001508655tslx:RevolvingCreditsFacilitiesMember2021-01-012021-12-310001508655us-gaap:SeriesCPreferredStockMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:BiohavenPharmaceuticalsIncMembertslx:PharmaceuticalsMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:DerivativeAssetInterestRateSwapFiveMemberus-gaap:LongMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:SecondLienLoanDueOctoberTwoThousandTwentyNineMembertslx:AstraAcquisitionCorpMember2021-12-310001508655tslx:StructuredCreditMembertslx:SignalPeakCloLLCSeriesTwoThousandEighteenFiveAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMember2022-12-310001508655tslx:SeriesAPreferredUnitsMembertslx:ClearCompanyLLCMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:InternetServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourFiveMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMemberus-gaap:BaseRateMember2022-12-3100015086552021-09-300001508655tslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanOneDueDecemberTwoThousandTwentyFiveMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:JeffersonMillCloLtdSeriesTwoThousandFifteenOneAMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:PianoSoftwareIncMembertslx:FirstLienLoanDueFebruaryTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:SecondLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001508655us-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2021-01-012021-12-310001508655us-gaap:AdditionalPaidInCapitalMember2019-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:StructuredProductOneMembertslx:CarlyleGlobalMarketStrategiesCLOLtdMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:EquityAndOtherInvestmentsMembertslx:MadisonParkCloSeriesTwoThousandEighteenTwentyEightAMember2022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:EmploymentHeroHoldingsPtyLtdMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesOneMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMembertslx:AlphaMidcoIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-310001508655tslx:CrunchtimeInformationSystemsIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMembertslx:FirstLienLoanDueJuneTwoThousandTwentyEightMember2022-12-310001508655tslx:FirstLienRevolvingLoanOctoberTwoThousandTwentyTwoMembertslx:LithiumTechnologiesLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:AlphaMidcoIncMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:TransportationMember2021-12-310001508655tslx:WarrantOneMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BenefitStreetPartnersCloLtdSeriesTwoThousandFifteenBRMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:OctagonInvestmentPartnersThirtyEightLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2022-02-172022-02-170001508655tslx:IRGSEHoldingCorpMembertslx:ClassAUnitsMembertslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2021-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2021-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesTwoMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMembertslx:BlueSnapIncMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-12-012021-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2022-12-310001508655tslx:AblFiloTermLoanDueAugustTwoThousandTwentySevenMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:ElysianFincoLtdMembertslx:DelayedDrawAndRevolverMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:IbisIntermediateCoMembertslx:FirstLienLoanDueMayTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveTwoMemberus-gaap:DebtSecuritiesMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:AxonifyIncMembertslx:ClassAOneUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:BearOpCoLLCMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMember2021-12-310001508655tslx:BearOpCoLLCMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMember2021-01-012021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:EquityAndOtherInvestmentsMembertslx:TRPAssetsLLCMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2014-01-012014-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:ShackeltonCloLtdSeries20157RaMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-12-310001508655tslx:FinancialServicesMemberus-gaap:CommonStockMembertslx:OxfordSquareCapitalCorpMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:InterestRateSwapTwelveMember2021-01-012021-12-310001508655tslx:TwentyTwentyFourNotesMember2020-01-012020-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2017-01-012017-12-310001508655tslx:SMPAHoldingsLLCMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:BiohavenPharmaceuticalsIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMembertslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:CeltraTechnologiesIncMember2022-01-012022-12-310001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:CarlyleGlobalMarketStrategiesCloLtdSeriesTwoThousandFourteenFourRaMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMembertslx:AssetValuationWaterfallMember2022-12-310001508655tslx:StructuredCreditMembertslx:SignalPeakCloLLCSeriesTwoThousandEighteenFiveAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:DerivativeAssetInterestRateSwapTwoMember2022-01-012022-12-310001508655tslx:EducationMembertslx:Astra2LHoldingsIILLCMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:WhiteboxCloILtdSeriesTwoThousandTwentyTwoAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFiveMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:HigherLogicLLCMembertslx:InternetServicesMember2022-12-310001508655tslx:RevolverMembertslx:WideOrbitIncMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtySixMembertslx:EquityAndOtherInvestmentsMembertslx:WindRiverCloLtdSeriesTwoThousandSeventeenOneAMember2022-12-310001508655srt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2021-01-012021-12-3100015086552019-12-310001508655tslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanOneDueDecemberTwoThousandTwentyFiveMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesTwoMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:ABLFILOTermLoanDueMayTwoThousandTwentySixMembertslx:ProjectPIntermediate2LLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:InterestRateSwapNineMember2022-01-012022-12-310001508655tslx:IRGSEHoldingCorpMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMembertslx:FirstLienRevolvingLoanJuneTwoThousandTwentyThreeMember2022-01-012022-12-310001508655tslx:InterestRateSwapThreeMember2021-01-012021-12-310001508655tslx:TransportationMember2022-12-310001508655tslx:TwentyTwentySixNotesMember2021-02-032021-02-030001508655tslx:TwentyTwentyFourNotesMember2020-02-052020-02-050001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:SecuredOvernightFinancingRateMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655tslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesCPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienRevolvingLoanDueOctoberTwoThousandAndTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2021-01-012021-12-310001508655tslx:ReliaQuestHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMembertslx:BusinessServicesMember2021-12-310001508655us-gaap:OverAllotmentOptionMember2021-03-012021-03-310001508655tslx:OfficeProductsMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:ABLFILOTermLoanMembertslx:USRParentIncMember2021-12-310001508655tslx:StructuredProductDueAprilTwoThousandThirtyThreeMembertslx:StructuredCreditMembertslx:RRLtdSeriesTwoThousandTwentyEightAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:PianoSoftwareIncMembertslx:FirstLienLoanDueFebruaryTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655us-gaap:WarrantMembertslx:WideOrbitIncMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapThreeMember2022-01-012022-12-310001508655tslx:MezzanineDebtInvestmentsMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:AstraAcquisitionCorpMembertslx:SecondLienLoanDueOctoberTwoThousandTwentyNineMember2022-12-310001508655tslx:InterestRateSwapOneMember2021-01-012021-12-310001508655tslx:AvidXchangeIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655us-gaap:RetainedEarningsMember2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:BiohavenPharmaceuticalsIncMember2021-12-310001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFourMembertslx:GTreasurySSLLCMember2022-12-310001508655tslx:BaseDividendMember2021-11-022021-11-020001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-01-262022-01-260001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:CrownPointCloLtdSeriesTwoThousandTwentyOneTenAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2020-05-052020-05-050001508655tslx:ChemicalsMembertslx:FirstLienLoanOneDueSeptemberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:ErlingLuxBidcoSarlMember2022-01-012022-12-310001508655tslx:EducationMembertslx:MembershipInterestMembertslx:Astra2LHoldingsIILLCMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:ABLFILOTermLoanDueMayTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:NinetyNineCentsOnlyStoresLLCMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2015-01-012015-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:BCTOAcePurchaserIncMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2022-12-310001508655tslx:InterestRateSwapElevenMember2022-01-012022-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2018-06-012018-06-300001508655tslx:PianoSoftwareIncMembertslx:SeriesCTwoPreferredSharesMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:CifcCloLtdSeriesTwoThousandEighteenThreeAMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyEightMembertslx:OutsystemsLuxcoMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueMarchTwentyTwentySixMembertslx:OmnigoSoftwareLLCMemberus-gaap:DebtSecuritiesMembertslx:OtherMember2021-01-012021-12-310001508655tslx:MoranFoodsLLCMemberus-gaap:DebtSecuritiesMembertslx:ABLFILOTermLoanDueAprilTwoThousandTwentyFourMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:PreferredUnitsMembertslx:MurchisonOilAndGasLlcMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:WarrantMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:ClassATwoUnitsMembertslx:NewportParentHoldingsLPMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:InterestRateSwapThirteenMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapEightMemberus-gaap:LongMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:AsgIiLlcMembertslx:HotelGamingAndLeisureMember2022-01-012022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2021-01-012021-12-310001508655tslx:SpecialDividendMember2021-02-170001508655tslx:TangoManagementConsultingLLCMembertslx:DelayedDrawAndRevolverMember2022-12-310001508655tslx:StewartParkCloLtdSeriesTwoThousandFifteenOneAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2022-01-012022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapThreeMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:BiohavenPharmaceuticalsIncMembertslx:PharmaceuticalsMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapSevenMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtySevenMembertslx:EquityAndOtherInvestmentsMembertslx:GulfStreamMeridianSeriesTwoThousandTwentyOneSixAMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:FirstLienLoanDueFebruaryTwoThousandTwentySevenMembertslx:LucidworksIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655tslx:PrimeRevenueIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyThreeMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:ClassATwoUnitsMembertslx:ReliaQuestLLCMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:WarrantMembertslx:WideOrbitIncMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwentyTwentyThreeNotesMember2018-01-012018-12-310001508655tslx:ConvertibleNoteDueSeptemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMember2022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:RevolverMember2022-12-310001508655us-gaap:FairValueInputsLevel2Membertslx:FirstLienDebtInvestmentsMember2022-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapSixMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapFourMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:HigherLogicLLCMembertslx:InternetServicesMember2021-12-310001508655us-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapOneMember2022-12-310001508655tslx:OutsystemsLuxcoMembertslx:DelayedDrawMember2022-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:GulfStreamMeridianSeriesTwoThousandTwentyOneFourAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:NeuintelLLCMembertslx:AblFiloTermLoanDueAugustTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentySixNotesMember2022-01-012022-12-310001508655tslx:DaySmartHoldingsLLCMembertslx:DelayedDrawMember2021-12-310001508655us-gaap:WarrantMembertslx:ValantMedicalSolutionsIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2021-01-012021-12-310001508655tslx:StructuredCreditMembertslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandSeventeenFourAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2021-12-310001508655tslx:DaySmartHoldingsLLCMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:GulfStreamMeridianSeriesTwoThousandTwentyOneFourAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:PrimeRevenueIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ForeScoutTechnologiesIncMember2022-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:EatonCloLtdSeriesTwoThousandTwentyOneAMember2022-12-310001508655tslx:CommunicationsMembertslx:WarrantOneMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJuneTwoThousandThirtyOneMembertslx:AllegroCloLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:DyeDurhamCorpMember2022-12-310001508655tslx:StructuredCreditMembertslx:OctagonInvestmentPartnersEighteenLimitedSeriesTwoThousandEighteenEighteenAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMember2022-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMember2021-12-310001508655tslx:CommunicationsMembertslx:WarrantOneMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:AssetValuationWaterfallMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveOneMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:ABLFILOTermLoanDueMayTwoThousandTwentySixMembertslx:ProjectPIntermediate2LLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap:FairValueInputsLevel2Member2021-12-310001508655us-gaap:SeriesCPreferredStockMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:MagnetiteCloLtdSeriesTwoThousandTwentyOneThirtyAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapElevenMember2021-01-012021-12-310001508655us-gaap:WarrantMemberus-gaap:FinancialServicesSectorMembertslx:EquityAndOtherInvestmentsMembertslx:PassportLabsIncMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienRevolvingLoanMayTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:ClinicientIncMemberus-gaap:HealthcareSectorMember2021-12-3100015086552022-09-300001508655tslx:DerivativeAssetInterestRateSwapOneMember2022-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Membertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:ChemicalsMemberus-gaap:DebtSecuritiesMembertslx:EuroInterbankOfferRateMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyEightMembertslx:ErlingLuxBidcoSarlMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:ClassATwoUnitsMembertslx:NewportParentHoldingsLPMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:ConvertibleNoteDueSeptemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMember2021-01-012021-12-3100015086552021-02-012021-02-280001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapSevenMember2022-12-310001508655tslx:StructuredCreditInvestmentsMember2022-01-012022-12-310001508655us-gaap:WarrantMembertslx:PharmaceuticalsMembertslx:TherapeuticsMDIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:SMATechnologiesHoldingsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembersrt:WeightedAverageMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655tslx:AutomotiveMembertslx:CarlstarGroupLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2022-12-310001508655tslx:EMSLinqIncMembertslx:RevolverMember2022-12-310001508655us-gaap:DomesticCountryMember2021-01-012021-12-310001508655us-gaap:AdditionalPaidInCapitalMember2022-01-012022-12-310001508655tslx:ClassATwoUnitsMembertslx:ReliaQuestLLCMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2021-12-310001508655tslx:BaseDividendMember2020-02-192020-02-190001508655tslx:FirstLienRevolvingLoanOctoberTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:LithiumTechnologiesLLCMembertslx:InternetServicesMember2022-12-310001508655country:LU2022-12-310001508655tslx:PianoSoftwareIncMembertslx:FirstLienLoanDueFebruaryTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyThreeMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyFourNotesMember2021-01-012021-12-310001508655tslx:BedBathAndBeyondIncMembertslx:AblFiloTermLoanDueAugustTwoThousandTwentySevenMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:CrownPointCloLtdSeriesTwoThousandTwentyOneTenAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FinancialServicesMemberus-gaap:CommonStockMembertslx:OxfordSquareCapitalCorpMembertslx:EquityAndOtherInvestmentsMember2021-12-3100015086552018-01-012018-12-310001508655tslx:PharmaceuticalsMember2022-12-310001508655srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:Octagon57LlcSeries20211AMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:PreferredUnitsMembertslx:MurchisonOilAndGasLlcMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:BCTOAcePurchaserIncMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapFiveMemberus-gaap:LongMember2021-12-310001508655tslx:StructuredProductTwoMembertslx:StructuredCreditMembertslx:CarlyleGlobalMarketStrategiesCLOLtdMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:FirstLienLoanDueNovemberTwoThousandTwentySevenMembertslx:Project44IncMemberus-gaap:DebtSecuritiesMembertslx:TransportationMember2021-01-012021-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductTwoMembertslx:StructuredCreditMembertslx:CarlyleGlobalMarketStrategiesCLOLtdMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:CarlyleGlobalMarketStrategiesCloLtdSeriesTwoThousandFourteenFourRaMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-10-012021-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesOneMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveOneMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AresCloLtdSeriesTwoThousandTwentyOneFiftyNineAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyFourMember2022-12-310001508655tslx:FirstLienDebtInvestmentsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:SecondLienDebtInvestmentsMembersrt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:TwoThousandTwentyThreeAndTwentyFourAndTwentySixNotesMember2022-01-012022-12-310001508655us-gaap:WarrantMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMembertslx:PassportLabsIncMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655tslx:AlphaMidcoIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-08-012022-08-010001508655tslx:StructuredCreditMembertslx:BenefitStreetPartnersCloLtdSeriesTwoThousandFifteenEightAMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-3100015086552021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:DyeDurhamCorpMember2021-12-3100015086552023-02-160001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:MDAmericaEnergyLimitedLiabilityCompanyMember2021-01-012021-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapMember2021-12-3100015086552022-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:MurchisonOilAndGasLlcMember2022-12-310001508655tslx:StructuredProductDueAprilTwoThousandThirtyThreeMembertslx:StructuredCreditMembertslx:MidoceanCreditCloLtdSeriesTwoThousandSixteenSixAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:WarrantMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMembertslx:PassportLabsIncMember2021-01-012021-12-310001508655tslx:SecuredOvernightFinancingRateMembertslx:NetwrixCorpMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJuneTwoThousandTwentyNineMembertslx:BusinessServicesMember2022-12-3100015086552015-08-040001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMembertslx:ConvertibleNoteDueMayTwoThousandTwentyEightMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwothousandTwentySixOneMembertslx:AxonifyIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2021-01-012021-12-310001508655tslx:EMSLinqIncMembertslx:EducationMembertslx:ClassBUnitsMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:WindRiverCloLtdSeries20142AMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:SpecialDividendMember2021-11-022021-11-020001508655tslx:NeuintelLLCMembertslx:DelayedDrawMember2021-12-310001508655tslx:IRGSEHoldingCorpMembertslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMembertslx:ClassCOneUnitsMember2021-12-310001508655tslx:FirstLienLoanDueMarchTwentyTwentySixMembertslx:OmnigoSoftwareLLCMemberus-gaap:DebtSecuritiesMembertslx:OtherMember2021-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:LeantaasHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:DestinySolutionsParentHoldingCompanyMember2021-01-012021-12-310001508655tslx:SupplementalDividendMember2021-02-172021-02-170001508655tslx:CommunicationsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueMayTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:AmericanMoneyManagementCorpCloLtdSeriesTwoThousandSixteenEighteenAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveFourMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyTwoConvertibleNotesMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueFebruaryTwoThousandTwentySevenMembertslx:LucidworksIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655tslx:StructuredCreditInvestmentsMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001508655tslx:BaseDividendMember2022-05-030001508655tslx:BswiftLlcMembertslx:EquityAndOtherInvestmentsMembertslx:ClassAOneUnitsMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:SecondLienDebtInvestmentsMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapSevenMember2021-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2022-01-012022-12-310001508655tslx:CommunicationsMember2022-12-310001508655us-gaap:TreasuryStockMember2022-01-012022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-01-012022-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:WhiteboxCloILtdSeriesTwoThousandTwentyTwoAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:TwentyTwentyThreeNotesMember2018-01-012018-01-310001508655tslx:DerivativeAssetInterestRateSwapFiveMember2021-01-012021-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:GulfStreamMeridianSeriesTwoThousandTwentyOneFourAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:InterestRateSwapElevenMember2021-01-012021-12-310001508655tslx:RevolvingCreditsFacilitiesMember2016-01-012016-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2017-02-280001508655tslx:DerivativeAssetInterestRateSwapOneMember2021-12-310001508655tslx:EducationMembertslx:RMCFIVCIVXXXVLPMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:CommonStockMember2019-12-310001508655tslx:EducationMember2021-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtySevenMembertslx:EquityAndOtherInvestmentsMembertslx:GulfStreamMeridianSeriesTwoThousandTwentyOneSixAMember2022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:DestinySolutionsParentHoldingCompanyMember2022-01-012022-12-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyFourNotesMember2022-01-012022-12-310001508655tslx:DerivativeAssetInterestRateSwapEightMember2021-01-012021-12-310001508655tslx:SupplementalDividendMember2022-05-030001508655tslx:MidwestMember2021-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienRevolvingLoanDecemberTwoThousandTwentySixMember2022-01-012022-12-3100015086552022-04-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2015-01-012015-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesOneMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:DaySmartHoldingsLLCMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:StructuredProductDueMayTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:AmericanMoneyManagementCorpCloLtdSeriesTwoThousandSixteenEighteenAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveOneMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:DerivativeAssetInterestRateSwapFourMember2021-01-012021-12-310001508655tslx:OtherMember2021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFourOneMembertslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMembertslx:VerdadResourcesIntermediateHoldingsLLCMember2021-12-310001508655tslx:BaseDividendMember2020-05-050001508655tslx:TwentyTwentyThreeNotesMember2021-12-310001508655tslx:NetwrixCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueJuneTwoThousandTwentyNineMember2022-12-310001508655tslx:TwoThousandTwentySixNotesMember2021-02-030001508655us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-01-012021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-12-310001508655tslx:SupplementalDividendMember2022-05-032022-05-030001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFourMembertslx:GTreasurySSLLCMember2022-01-012022-12-310001508655tslx:GTreasurySSLLCMembertslx:DelayedDrawMember2021-12-310001508655us-gaap:RetainedEarningsMember2020-01-012020-12-310001508655us-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapThreeMember2021-12-310001508655us-gaap:RetainedEarningsMember2021-12-310001508655us-gaap:WarrantMembertslx:PharmaceuticalsMembertslx:TherapeuticsMDIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-08-010001508655tslx:CostModelMemberus-gaap:FairValueInputsLevel3Membertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PageUpPeopleLtdMember2022-12-310001508655tslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMembertslx:TherapeuticsMDIncMembertslx:FirstLienLoanDueMarchTwentyTwentyFourMember2021-12-310001508655tslx:SpecialDividendTwoMember2020-02-190001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMemberus-gaap:HealthcareSectorMembertslx:IntegratedPracticeSolutionsIncMember2022-12-310001508655tslx:PharmaceuticalsMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveOneMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:CordanceOperationsLlcMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyThreeAndTwentyFourAndTwentySixNotesMember2022-01-012022-12-310001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMembertslx:ConvertibleNoteDueMayTwoThousandTwentyEightMember2021-01-012021-12-310001508655tslx:SecuredOvernightFinancingRateMembertslx:PingIdentityHoldingCorporationMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyNineMember2022-12-310001508655tslx:ConvertibleNoteDueSeptemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:PrimeRevenueIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:FirstLienRevolvingLoanJuneTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-12-310001508655tslx:BearOpCoLLCMembertslx:DelayedDrawMember2022-12-310001508655tslx:StructuredProductDueAprilTwoThousandThirtyThreeMembertslx:StructuredCreditMembertslx:RRLtdSeriesTwoThousandTwentyEightAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:InterestRateSwapSevenMember2021-01-012021-12-310001508655tslx:IRGSEHoldingCorpMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2020-12-310001508655tslx:InterestRateSwapFourMember2021-01-012021-12-310001508655tslx:StructuredCreditMembertslx:GoldentreeCloLtdSeriesTwoThousandTwentySevenAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyFourMember2022-01-012022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapTwoMember2021-01-012021-12-310001508655tslx:SprinklrIncMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:FinancialServicesMemberus-gaap:CommonStockMembertslx:OxfordSquareCapitalCorpMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:ValidityIncMemberus-gaap:SeriesAPreferredStockMembertslx:MarketingServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueAprilTwoThousandThirtyThreeMembertslx:StructuredCreditMembertslx:MidoceanCreditCloLtdSeriesTwoThousandSixteenSixAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMember2022-12-310001508655tslx:WarrantTwoMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:SecondLienLoanDueOctoberTwoThousandTwentyNineMembertslx:AstraAcquisitionCorpMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:WideOrbitIncMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentyFiveMembertslx:BusinessServicesMember2022-12-310001508655country:NO2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:IRGSEHoldingCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:EuroInterbankOfferRateMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyEightMembertslx:OutsystemsLuxcoMember2022-12-310001508655tslx:FirstLienRevolvingLoanMayTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:ClinicientIncMemberus-gaap:HealthcareSectorMember2021-01-012021-12-310001508655tslx:TwentyTwentySixNotesMember2021-12-310001508655tslx:StructuredCreditMembertslx:OctagonInvestmentPartnersEighteenLimitedSeriesTwoThousandEighteenEighteenAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:PrimePayIntermediateLLCMembertslx:DelayedDrawMember2022-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:HigherLogicLLCMembertslx:InternetServicesMember2021-01-012021-12-310001508655tslx:StructuredCreditMembertslx:KkrCloLtdFortyNineAMembertslx:StructuredProductDueJulyTwoThousandThirtyFiveMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:AcceoSolutionsIncMembertslx:BusinessServicesMember2021-01-012021-12-310001508655tslx:IRGSEHoldingCorpMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMembertslx:FirstLienRevolvingLoanJuneTwoThousandTwentyThreeMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapEightMember2022-12-310001508655tslx:BaseDividendMember2021-02-172021-02-170001508655tslx:RevolverMembertslx:WideOrbitIncMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:GTreasurySSLLCMembertslx:FirstLienLoanDueAprilTwoThousandTwentyThreeMember2021-12-310001508655tslx:HomecareSoftwareSolutionsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2022-12-310001508655tslx:TwentyTwentyFourNotesMember2019-11-012019-11-300001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:SecuredOvernightFinancingRateMembertslx:EDBParentLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:BtrsHoldingsIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyEightMember2022-01-012022-12-310001508655us-gaap:SeriesFPreferredStockMembertslx:LucidworksIncMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:ClassAUnitsMembertslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwentyTwentySixNotesMember2022-12-310001508655tslx:AxonifyIncMembertslx:ClassAOneUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:IRGSEHoldingCorpMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-01-012021-12-310001508655tslx:CarvalCloIiiLtdSeriesTwoThousandNineteenTwoAMembertslx:StructuredProductDueJulyTwoThousandThirtyTwoMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2017-02-012017-02-280001508655us-gaap:OverAllotmentOptionMember2021-03-310001508655tslx:DerivativeLiabilitiesInterestRateSwapOneMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyThreeAndTwentyFourAndTwentySixNotesMember2021-01-012021-12-310001508655tslx:AxonifyIncMembertslx:FirstLienLoanDueMayTwothousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMembertslx:BlueSnapIncMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapSixMember2021-12-310001508655tslx:AvidXchangeIncMembertslx:DelayedDrawMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:ShackeltonCloLtdSeries20157RaMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BayshoreIntermediate2LPMembertslx:RevolverMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ReliaQuestHoldingsLLCMember2021-12-310001508655tslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:IbisIntermediateCoMembertslx:FirstLienLoanDueMayTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2021-12-310001508655us-gaap:AdditionalPaidInCapitalMember2020-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:BtrsHoldingIncMember2022-12-310001508655tslx:PrimeRevenueIncMembertslx:DelayedDrawAndRevolverMember2021-12-310001508655tslx:BearOpCoLLCMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMember2021-12-310001508655us-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapEightMember2021-12-310001508655tslx:ABLFILOTermLoanDueMayTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:NinetyNineCentsOnlyStoresLLCMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:AutomotiveMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:WarrantMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655srt:PartnershipInterestMembertslx:EducationMembertslx:RMCFIVCIVXXXVLPMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredCreditInvestmentsMember2021-01-012021-12-310001508655tslx:SupplementalDividendMember2021-08-030001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourTwoMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-3100015086552022-08-012022-08-310001508655tslx:DerivativeAssetInterestRateSwapFiveMember2022-01-012022-12-310001508655tslx:SecondLienDebtInvestmentsMember2022-01-012022-12-310001508655tslx:CostModelMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2021-12-310001508655us-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2022-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:LeantaasHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655tslx:FirstLienLoanDueAugustTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:DerivativeAssetInterestRateSwapThreeMemberus-gaap:LongMember2021-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2022-12-310001508655tslx:CarlstarGroupLLCMembertslx:RevolverMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:BattalionCloLtdSeriesTwoThousandTwentyOneTwentyOneAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesTwoMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtySixMembertslx:EquityAndOtherInvestmentsMembertslx:WindRiverCloLtdSeriesTwoThousandSeventeenOneAMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2020-01-012020-12-310001508655us-gaap:ShortMembertslx:DerivativeLiabilitiesInterestRateSwapOneMember2022-12-310001508655tslx:PianoSoftwareIncMembertslx:SeriesCTwoPreferredSharesMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentySixNotesMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentySixMembertslx:AxonifyIncMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:IlluminateEducationIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyTwoMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:TwoThousandTwentyThreeNotesMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveTwoMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:AvalaraIncMembertslx:RevolverMember2022-12-310001508655us-gaap:NondesignatedMember2022-12-310001508655tslx:SubordinatedNoteDueSeptemberTwoThousandTwentySixMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:AmericanAchievementCorpMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:TangoManagementConsultingLLCMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2020-01-012020-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-12-310001508655us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655tslx:SecondLienDebtInvestmentsMember2021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:PrimePayIntermediateLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMembertslx:TRPAssetsLLCMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:CedarFundingCloLtdSeriesTwoThousandEighteenSevenAMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:MoranFoodsLLCMemberus-gaap:DebtSecuritiesMembertslx:ABLFILOTermLoanDueAprilTwoThousandTwentyFourMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:FirstLienDebtInvestmentsMember2020-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentySixMembertslx:PassportLabsIncMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:IbisUSBlockerCoMember2021-01-012021-12-310001508655tslx:BaseDividendMember2020-11-040001508655us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembersrt:WeightedAverageMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2021-12-310001508655tslx:ReliaQuestHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMembertslx:BusinessServicesMember2022-12-310001508655tslx:InterestRateSwapSevenMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveFourMemberus-gaap:DebtSecuritiesMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:WarrantMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMembertslx:PassportLabsIncMember2021-12-310001508655tslx:DrydenSeniorLoanFundSeriesTwoThousandTwentyEightySixAMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:Octagon57LlcSeries20211AMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:UnfundedLoanCommitmentMember2021-12-3100015086552021-12-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveMember2021-12-310001508655us-gaap:TreasuryStockMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapFiveMemberus-gaap:ShortMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2021-12-3100015086552018-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AblFirstLienLoanDueAugustTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:DesignerBrandsIncMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:OfficeProductsMembertslx:ABLFILOTermLoanDueAprilTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:USRParentIncMember2022-01-012022-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2022-12-310001508655tslx:CedarFundingCloLtdSeriesTwoThousandEighteenSevenAMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:DrydenSeniorLoanFundSeriesTwoThousandTwentyEightySixAMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:EuroInterbankOfferRateMembertslx:KyribaCorpMember2022-12-310001508655tslx:CrunchtimeInformationSystemsIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMembertslx:FirstLienLoanDueJuneTwoThousandTwentyEightMember2022-01-012022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapOneMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-310001508655tslx:InterestRateSwapSixMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:IRGSEHoldingCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-3100015086552021-07-012021-09-300001508655tslx:WideOrbitIncMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentyFiveMembertslx:BusinessServicesMember2022-12-3100015086552020-04-012020-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:HigherLogicLLCMembertslx:InternetServicesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:SeriesCPreferredStockMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesOneMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2019-11-300001508655tslx:DelayedDrawAndRevolverMembertslx:HornetsecurityHoldingGmbhMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-01-012022-12-310001508655tslx:MitnickTaAggregatorLpMembertslx:MembershipInterestMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:TwoThousandTwentyThreeNotesMember2018-01-310001508655tslx:DelayedDrawAndRevolverMembertslx:LucidworksIncMember2022-12-310001508655tslx:FirstLienLoanDueNovemberTwoThousandTwentySevenMembertslx:Project44IncMemberus-gaap:DebtSecuritiesMembertslx:TransportationMember2021-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesDPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyThreeNotesMember2018-01-012018-01-310001508655tslx:IbisIntermediateCoMembertslx:DelayedDrawMember2022-12-310001508655tslx:SubordinatedNoteDueSeptemberTwoThousandTwentySixMembertslx:AmericanAchievementCorpMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:EquityAndOtherInvestmentsMembertslx:MadisonParkCloSeriesTwoThousandEighteenTwentyEightAMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveOneMembertslx:DaySmartHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2022-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-12-310001508655tslx:BaseDividendMember2022-11-102022-11-100001508655tslx:IRGSEHoldingCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyThreeMembertslx:FrontlineTechnologiesGroupLLCMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJanuaryTwoThousandTwentyEightMembertslx:ElysianFincoLtdMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:HotelGamingAndLeisureMembertslx:ClassCOneUnitsMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:EDBParentLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMemberus-gaap:HealthcareSectorMembertslx:IntegratedPracticeSolutionsIncMember2021-01-012021-12-310001508655us-gaap:FinancialServicesSectorMember2021-12-310001508655tslx:InterestRateSwapTenMember2021-01-012021-12-310001508655tslx:CommunicationsMembertslx:WarrantOneMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMembertslx:MerativeLPMembertslx:FirstLienLoanDueJuneTwoThousandTwentyEightMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2021-12-310001508655tslx:WarrantOneMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:FirstLienNoteDueMarchTwoThousandTwentyNineMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:TIBCOSoftwareIncMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyFourNotesMember2020-02-052020-02-0500015086552020-07-012020-09-300001508655tslx:HomecareSoftwareSolutionsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2022-01-012022-12-310001508655tslx:SMATechnologiesHoldingsLLCMembertslx:ClassAUnitsMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2022-02-170001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:OctagonInvestmentPartnersEighteenLimitedSeriesTwoThousandEighteenEighteenAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:ReliaQuestLLCMembertslx:BusinessServicesMembertslx:ClassAOneUnitsMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:PrimePayIntermediateLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixTwoMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:SignalPeakCloLLCSeriesTwoThousandEighteenFiveAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-01-012022-12-310001508655tslx:CapitalGainsAccrueFollowingMarchThirtyFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655us-gaap:SeriesEPreferredStockMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMembertslx:EmploymentHeroHoldingsPtyLtdMember2022-12-310001508655tslx:TangoManagementConsultingLLCMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:DerivativeLiabilitiesInterestRateSwapTwoMemberus-gaap:LongMember2021-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2022-01-012022-12-310001508655tslx:StructuredCreditMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PrimeRevenueIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyThreeMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:WarrantMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:CommonStockMember2021-02-280001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveMember2022-01-012022-12-310001508655tslx:DerivativeAssetInterestRateSwapTwoMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMembertslx:ConvertibleNoteDueMayTwoThousandTwentyEightMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:AsgIiLlcMembertslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapThreeMember2022-01-012022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-01-012022-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:SecondLienLoanDueOctoberTwoThousandTwentyNineMembertslx:AstraAcquisitionCorpMember2021-12-310001508655country:CA2021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentySixMembertslx:PassportLabsIncMember2021-12-310001508655tslx:SeriesAPreferredUnitsMembertslx:ClearCompanyLLCMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:MDAmericaEnergyLimitedLiabilityCompanyMember2021-12-310001508655tslx:AvidXchangeIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:PianoSoftwareIncMembertslx:FirstLienLoanDueFebruaryTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-01-012021-12-310001508655tslx:SupplementalDividendMember2021-08-032021-08-030001508655tslx:CommunicationsMembertslx:ClassAUnitsMembertslx:CeltraTechnologiesIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:CeltraTechnologiesIncMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapMember2021-01-012021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PrimePayIntermediateLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixFourMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapEightMember2021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:SecondLienDebtInvestmentsMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2019-01-012019-12-310001508655tslx:TwoThousandTwentyFourNotesMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueNovemberTwoThousandTwentySevenMembertslx:Project44IncMemberus-gaap:DebtSecuritiesMembertslx:TransportationMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMembertslx:TherapeuticsMDIncMembertslx:FirstLienLoanDueMarchTwentyTwentyFourMember2021-12-310001508655tslx:TwentyTwentyFourNotesMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:MitnickCorporatePurchaserIncMembertslx:BusinessServicesMembertslx:FirstLienLoanDueMayTwoThousandTwentyNineMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourFourMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:MDAmericaEnergyLLCMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-01-012021-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:BattalionCloLtdSeriesTwoThousandTwentyOneTwentyOneAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:IbisIntermediateCoMembertslx:FirstLienLoanDueMayTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2022-01-012022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PageUpPeopleLtdMember2021-12-310001508655tslx:FirstLienDebtInvestmentsMember2021-01-012021-12-310001508655tslx:EducationMembertslx:RMCFIVCIVXXXVLPMembertslx:EquityAndOtherInvestmentsMember2022-12-3100015086552020-01-012020-03-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:DerivativeLiabilitiesInterestRateSwapTwoMemberus-gaap:LongMember2022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveOneMembertslx:PageUpPeopleLtdMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapMember2022-01-012022-12-310001508655tslx:StructuredProductDueJuneTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:AllegroCloLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:MurchisonOilAndGasLlcMembertslx:DelayedDrawMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMembertslx:ManufacturingMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:AvalaraIncMember2022-12-310001508655tslx:AmericanAchievementCorpMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:CarlstarGroupLLCMemberus-gaap:DebtSecuritiesMemberus-gaap-supplement:AutomotiveSectorMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2022-01-012022-12-310001508655tslx:CommunicationsMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembersrt:PartnershipInterestMembertslx:EquityAndOtherInvestmentsMembertslx:TRPAssetsLLCMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2021-01-012021-12-310001508655tslx:WindRiverCloLtdSeriesTwoThousandEighteenThreeAMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourFiveMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655us-gaap:AssetPledgedAsCollateralMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMember2021-12-310001508655us-gaap:RevolvingCreditFacilityMember2021-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMemberus-gaap:BaseRateMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMembertslx:EmploymentHeroHoldingsPtyLtdMember2022-12-310001508655tslx:ClassAUnitsMembertslx:SMPAHoldingsLLCMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:MarketingServicesMember2022-12-310001508655tslx:InterestRateSwapFourteenMember2021-01-012021-12-310001508655tslx:DelayedDrawMembertslx:AxonifyIncMember2022-12-310001508655us-gaap:WarrantMembertslx:PharmaceuticalsMembertslx:TherapeuticsMDIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:WindRiverCloLtdSeries20142AMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesCPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveTwoMemberus-gaap:DebtSecuritiesMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:SeriesDPreferredStockMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:AdditionalPaidInCapitalMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2020-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2020-12-310001508655us-gaap:CommonStockMember2020-12-310001508655tslx:TwoThousandTwentyFourNotesMember2021-01-012021-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapThreeMember2021-12-310001508655us-gaap:HealthcareSectorMember2021-12-310001508655tslx:PrimeRevenueIncMembertslx:DelayedDrawAndRevolverMember2022-12-310001508655tslx:CarlyleGlobalMarketStrategiesCloLtdSeriesTwoThousandFourteenFourRaMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapTwoMember2021-12-3100015086552021-10-012021-12-310001508655tslx:BaseDividendMember2021-11-020001508655tslx:DaySmartHoldingsLLCMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:ValidityIncMemberus-gaap:SeriesAPreferredStockMembertslx:MarketingServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:ProjectPIntermediate2LLCMembertslx:ABLFILOTermLoanDueMayTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:ABLFILOTermLoanDueMayTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:NinetyNineCentsOnlyStoresLLCMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:WarrantOneMembertslx:PharmaceuticalsMembertslx:TherapeuticsMDIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueJuneTwoThousandThirtyOneMembertslx:WhiteboxCloILtdSeriesTwoThousandTwentyTwoAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-09-300001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:StructuredProductMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:CommonStockMember2021-12-310001508655us-gaap:WarrantMembertslx:CommunicationsMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapTwoMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeAssetInterestRateSwapTwoMember2021-12-3100015086552022-03-310001508655tslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:EatonCloLtdSeriesTwoThousandTwentyOneAMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueAugustTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-3100015086552020-10-012020-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:IbisUSBlockerCoMember2022-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMembertslx:AssetValuationWaterfallMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveOneMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:ValidityIncMemberus-gaap:SeriesAPreferredStockMembertslx:MarketingServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-3100015086552020-01-012020-12-310001508655tslx:ChemicalsMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:TangoManagementConsultingLLCMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Member2021-12-310001508655tslx:DaySmartHoldingsLLCMembertslx:FirstLienRevolvingLoanOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:MerativeLPMemberus-gaap:HealthcareSectorMembertslx:FirstLienLoanDueJuneTwoThousandTwentyEightMember2022-12-310001508655tslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMember2021-12-3100015086552021-02-280001508655tslx:ABLFILOTermLoanDueMayTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:NinetyNineCentsOnlyStoresLLCMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:GTreasurySSLLCMembertslx:DelayedDrawMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:MarketingServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:JeffersonMillCloLtdSeriesTwoThousandFifteenOneAMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:ClassAUnitsMembertslx:TradingScreenIncMemberus-gaap:FinancialServicesSectorMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapNineMember2021-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentySixMembertslx:AxonifyIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2021-01-012021-12-310001508655tslx:IbisIntermediateCoMembertslx:FirstLienLoanDueMayTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:SecuredOvernightFinancingRateMembertslx:HomecareSoftwareSolutionsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:HealthcareSectorMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:BiohavenPharmaceuticalsIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMembertslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMember2021-12-3100015086552022-07-012022-09-300001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMembertslx:AssetValuationWaterfallMember2021-12-310001508655tslx:CommonUnitsMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:CeltraTechnologiesIncMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMarchTwentyTwentySixMembertslx:OmnigoSoftwareLLCMemberus-gaap:DebtSecuritiesMembertslx:OtherMember2021-12-310001508655tslx:BaseDividendMember2022-11-010001508655tslx:WarrantOneMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyThreeMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMember2022-12-310001508655tslx:StructuredCreditMembertslx:KkrCloLtdFortyNineAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJulyTwoThousandThirtyFiveMember2022-01-012022-12-310001508655tslx:FinancialServicesMembertslx:AvidXchangeIncMemberus-gaap:CommonStockMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:EuroInterbankOfferRateMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveOneMember2021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:EuroInterbankOfferRateMember2021-12-310001508655tslx:IRGSEHoldingCorpMembertslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMembertslx:ClassCOneUnitsMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyTwoMembertslx:LithiumTechnologiesLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655tslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:TreasuryStockMember2020-01-012020-12-310001508655tslx:SupplementalDividendMember2021-05-042021-05-040001508655tslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:EquityAndOtherInvestmentsMembertslx:MadisonParkCloSeriesTwoThousandEighteenTwentyEightAMember2022-12-310001508655tslx:WideOrbitIncMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentyFiveMembertslx:BusinessServicesMember2021-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:InterestRateSwapMember2021-01-012021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:CommonStockMembertslx:OxfordSquareCapitalCorpMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ForeScoutTechnologiesIncMember2021-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2014-01-012014-12-310001508655us-gaap:CommonStockMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:PrimePayIntermediateLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:TwentyTwentyThreeNotesMember2019-01-012019-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwentyTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:TRPAssetsLLCMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2020-01-012020-12-310001508655tslx:TangoManagementConsultingLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:LithiumTechnologiesLLCMembertslx:RevolverMember2021-12-310001508655tslx:InterestRateSwapFiveMember2021-01-012021-12-310001508655us-gaap:RetainedEarningsMember2021-01-012021-12-310001508655tslx:NewportParentHoldingsLPMembertslx:ClassATwoUnitsMemberus-gaap:FinancialServicesSectorMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienNoteDueMarchTwoThousandTwentyNineMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:TIBCOSoftwareIncMember2022-12-310001508655tslx:EquityAndOtherInvestmentsMember2020-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:BlackScholesModelMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueMarchTwoThousandTwentyNineMembertslx:TIBCOSoftwareIncMember2022-12-310001508655tslx:NeuintelLLCMembertslx:DelayedDrawMember2022-12-310001508655tslx:FirstLienDebtInvestmentsMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapOneMember2022-01-012022-12-310001508655tslx:InternetServicesMember2022-12-310001508655us-gaap:SeriesFPreferredStockMembertslx:LucidworksIncMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:SupplementalDividendMember2022-02-170001508655tslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SouthwickParkCloLtdSeries20194AMembertslx:StructuredProductDueJulyTwoThousandThirtyTwoMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2022-08-022022-08-020001508655us-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMembertslx:AssetValuationWaterfallMember2021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentySixMembertslx:PassportLabsIncMember2021-01-012021-12-310001508655tslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:AdditionalPaidInCapitalMember2022-12-310001508655tslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMembertslx:NetwrixCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-01-012021-12-310001508655tslx:AresCloLtdSeriesTwoThousandTwentyOneFiftyNineAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyFourMember2022-01-012022-12-310001508655tslx:EMSLinqIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2022-01-012022-12-310001508655tslx:SeriesCOnePreferredSharesMembertslx:PianoSoftwareIncMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655srt:PartnershipInterestMembertslx:EducationMembertslx:RMCFIVCIVXXXVLPMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2022-01-012022-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienRevolvingLoanDecemberTwoThousandTwentySixMember2022-12-310001508655tslx:FirstLienNoteDueJuneTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:MarketingServicesMembertslx:AcousticLPMember2021-12-310001508655tslx:BaseDividendMember2020-11-042020-11-040001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:ShackeltonCloLtdSeries20157RaMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:ReliaQuestHoldingsLLCMembertslx:SecuredOvernightFinancingRateMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeLiabilitiesInterestRateSwapOneMember2022-12-310001508655tslx:InterestRateSwapSixMember2021-01-012021-12-310001508655tslx:PingIdentityCorporationMembertslx:RevolverMember2022-12-310001508655tslx:HomecareSoftwareSolutionsLLCMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyNineMember2022-01-012022-12-310001508655us-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2020-08-042020-08-040001508655tslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMembertslx:TherapeuticsMDIncMembertslx:FirstLienLoanDueMarchTwentyTwentyFourMember2021-01-012021-12-310001508655tslx:BlueSnapIncMembertslx:DelayedDrawAndRevolverMember2021-12-310001508655tslx:NortheastMember2022-12-310001508655tslx:InterestRateSwapTwoMember2021-01-012021-12-310001508655tslx:DrydenSeniorLoanFundSeriesTwoThousandTwentyEightySixAMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655country:GB2022-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesDPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:SouthwickParkCloLtdSeries20194AMembertslx:StructuredProductDueJulyTwoThousandThirtyTwoMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:MidoceanCreditCloLtdSeries20189AMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveTwoMemberus-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2021-12-310001508655tslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655tslx:SecondLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-12-310001508655tslx:CommunicationsMembertslx:ClassAUnitsMembertslx:CeltraTechnologiesIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:DebtSecuritiesMembertslx:ConvertibleNotesDueJuneTwoThousandTwentySevenMembertslx:EmploymentHeroHoldingsPtyLtdMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:TRPAssetsLLCMember2021-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:FutureRealizedCapitalGainsPriorToAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2020-03-310001508655us-gaap:SeriesCPreferredStockMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:HealthcareSectorMember2022-12-310001508655tslx:AvidXchangeIncMemberus-gaap:FinancialServicesSectorMemberus-gaap:CommonStockMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapNineMember2021-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapTwoMember2022-12-310001508655tslx:ParkAvenueInstitutionalAdvisersCloLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SupplementalDividendMember2021-05-040001508655tslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMember2021-12-3100015086552021-04-012021-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMemberus-gaap:HealthcareSectorMembertslx:IntegratedPracticeSolutionsIncMember2021-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixTwoMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2020-01-012020-12-310001508655tslx:ClassAUnitsMembertslx:ValantMedicalSolutionsIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:StructuredProductDueAprilTwoThousandThirtyThreeMembertslx:StructuredCreditMembertslx:MidoceanCreditCloLtdSeriesTwoThousandSixteenSixAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:TIBCOSoftwareIncMembertslx:FirstLienLoanDueMarchTwoThousandTwentyNineMember2022-12-310001508655tslx:ABLFILOTermLoanDueMayTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:NinetyNineCentsOnlyStoresLLCMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueAugustTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655tslx:ReliaQuestHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMembertslx:BusinessServicesMember2022-01-012022-12-3100015086552019-01-012019-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2021-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2021-01-012021-12-310001508655tslx:ClassAUnitsMembertslx:NeuintelLLCMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655tslx:BearOpCoLLCMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMember2022-01-012022-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:KkrCloLtdFortyNineAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJulyTwoThousandThirtyFiveMember2022-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyThreeMembertslx:FrontlineTechnologiesGroupLLCMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapSevenMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyThreeNotesMember2021-01-012021-12-310001508655us-gaap:DomesticCountryMember2022-01-012022-12-310001508655tslx:StructuredCreditMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveMember2021-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2018-06-300001508655tslx:EducationMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2020-12-310001508655us-gaap:AdditionalPaidInCapitalMember2021-01-012021-12-3100015086552021-06-300001508655tslx:SecondLienDebtInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:DestinySolutionsParentHoldingCompanyMember2021-12-310001508655tslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveTwoMembertslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapFourMember2022-12-310001508655us-gaap:SeriesDPreferredStockMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:CeltraTechnologiesIncMember2021-12-310001508655tslx:StructuredProductMembertslx:StructuredCreditMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwentyTwentyFourNotesMember2022-12-310001508655tslx:PrimeRevenueIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMember2022-01-012022-12-310001508655us-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:GTreasurySSLLCMember2022-12-310001508655tslx:LithiumTechnologiesLLCMembertslx:RevolverMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:ExtraHopNetworksIncMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2021-12-310001508655tslx:PharmaceuticalsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueAugustTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655tslx:InvestmentAdvisoryAgreementMember2021-01-012021-12-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:InterestRateSwapMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:IbisUSBlockerCoMember2022-01-012022-12-310001508655tslx:AresLoanFundingILtdSeriesTwoThousandTwentyOneAlfaClassEMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapTwoMemberus-gaap:ShortMember2021-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesCPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2022-12-310001508655tslx:DaySmartHoldingsLLCMembertslx:FirstLienRevolvingLoanOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:BiohavenPharmaceuticalsIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMembertslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:BCTOAcePurchaserIncMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:BearOpCoLLCMembertslx:SecuredOvernightFinancingRateMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMember2022-12-310001508655tslx:SprinklrIncMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-08-012022-08-310001508655tslx:EmploymentHeroHoldingsPtyLtdMembertslx:DelayedDrawAndRevolverMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:ClinicientIncMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourThreeMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:CeltraTechnologiesIncMember2022-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2020-01-012020-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2020-01-012020-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveTwoMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655srt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2020-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:HigherLogicLLCMembertslx:InternetServicesMember2022-12-310001508655tslx:RealizedCapitalGainsAccruedPriorToMarchThirtyFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655tslx:ChemicalsMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyEightMembertslx:ErlingLuxBidcoSarlMember2022-01-012022-12-310001508655srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655tslx:ErlingLuxBidcoSarlMembertslx:DelayedDrawAndRevolverMember2022-12-310001508655us-gaap:SeriesEPreferredStockMembertslx:EquityAndOtherInvestmentsMembertslx:EmploymentHeroHoldingsPtyLtdMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:NetwrixCorpMembertslx:BusinessServicesMember2021-12-310001508655tslx:TwentyTwentyThreeNotesMember2020-01-012020-12-3100015086552021-01-012021-12-310001508655us-gaap:CommonStockMembertslx:InternetServicesMembertslx:BayshoreIntermediate2LPMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveOneMembertslx:DaySmartHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:BankBillSwapBidRateMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:StewartParkCloLtdSeriesTwoThousandFifteenOneAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:LucidworksIncMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapThreeMember2021-01-012021-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMember2022-01-012022-12-310001508655tslx:IRGSEHoldingCorpMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:IRGSEHoldingCorpMemberus-gaap:DebtSecuritiesMembertslx:FirstLienRevolvingLoanJuneTwoThousandTwentyThreeMembertslx:HotelGamingAndLeisureMember2022-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueJulyTwentyTwentyFourMembertslx:LucidworksIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:StructuredProductDueJuneTwoThousandThirtyOneMembertslx:AllegroCloLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-01-012022-12-310001508655tslx:StructuredCreditMembertslx:BenefitStreetPartnersCloLtdSeriesTwoThousandFifteenEightAMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentyThreeNotesMember2022-12-310001508655tslx:SupplementalDividendMember2020-11-042020-11-040001508655tslx:WindRiverCloLtdSeries20142AMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:SupplementalDividendMember2021-11-020001508655tslx:HomecareSoftwareSolutionsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyNineMemberus-gaap:HealthcareSectorMember2022-12-310001508655us-gaap:DomesticCountryMember2021-12-310001508655tslx:ClassATwoUnitsMembertslx:NewportParentHoldingsLPMemberus-gaap:FinancialServicesSectorMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:RetainedEarningsMember2020-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:ClassAUnitsMembertslx:NeuintelLLCMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:RisksRelatedToOurPortfolioCompanyInvestmentsMember2022-01-012022-12-310001508655tslx:HornetsecurityHoldingGmbhMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueNovemberTwoThousandTwentyNineMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655tslx:BlueSnapIncMembertslx:DelayedDrawAndRevolverMember2022-12-310001508655us-gaap:CommonStockMember2020-01-012020-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel1Member2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentySixMembertslx:PassportLabsIncMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapNineMember2021-12-310001508655tslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:ABLFILOTermLoanDueMayTwoThousandTwentySixMembertslx:ProjectPIntermediate2LLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMember2022-12-310001508655tslx:SprinklrIncMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BswiftLlcMembertslx:FirstLienLoanDueNovemberTwoThousandTwentyEightMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMembertslx:ConvertibleNoteDueMayTwoThousandTwentyEightMember2021-12-310001508655tslx:FirstLienRevolvingLoanDueOctoberTwoThousandAndTwentySevenMembertslx:CrunchtimeInformationSystemsIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:RevolverMember2021-12-310001508655us-gaap:TreasuryStockMember2021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:NetwrixCorpMember2021-12-310001508655tslx:PrimePayIntermediateLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixTwoMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:RisksRelatedToOurBusinessAndStructureMember2022-01-012022-12-310001508655us-gaap:AdditionalPaidInCapitalMember2021-12-310001508655tslx:BaseDividendMember2021-08-032021-08-030001508655us-gaap:WarrantMembertslx:WideOrbitIncMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveTwoMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:NetwrixCorpMember2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2021-12-310001508655tslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMembertslx:AlphaMidcoIncMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourTwoMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixOneMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:AcceoSolutionsIncMember2022-12-310001508655tslx:ManufacturingMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapOneMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapSevenMember2021-12-310001508655tslx:SMATechnologiesHoldingsLLCMembertslx:ClassBUnitsMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SMATechnologiesHoldingsLLCMembertslx:ClassBUnitsMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:WarrantMembertslx:WideOrbitIncMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueJanuaryTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:HigherLogicLLCMembertslx:InternetServicesMember2021-12-310001508655srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapSevenMember2022-12-310001508655tslx:CommonUnitsMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:CrownPointCloLtdSeriesTwoThousandTwentyOneTenAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:VoyaCloLtdSeries20183AMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:InvestmentAdvisoryAgreementMember2022-01-012022-12-310001508655tslx:ReliaQuestLLCMembertslx:BusinessServicesMembertslx:ClassAOneUnitsMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:OfficeProductsMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2020-02-052020-02-050001508655tslx:StructuredCreditMembertslx:GoldentreeCloLtdSeriesTwoThousandTwentySevenAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyFourMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueFebruaryTwoThousandTwentySevenMembertslx:LucidworksIncMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655tslx:MidwestMember2022-12-310001508655tslx:PingIdentityHoldingCorporationMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyNineMember2022-12-310001508655tslx:GeneralRiskFactorsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentyThreeNotesMember2018-01-012018-01-310001508655tslx:FirstLienLoanDueNovemberTwoThousandTwentySevenMembertslx:Project44IncMemberus-gaap:DebtSecuritiesMembertslx:TransportationMember2022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapTwoMember2022-12-310001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:MitnickCorporatePurchaserIncMembertslx:BusinessServicesMembertslx:FirstLienLoanDueMayTwoThousandTwentyNineMember2022-12-310001508655tslx:FirstLienLoanDueMarchTwoThousandTwentySixMembertslx:OmnigoSoftwareLLCMemberus-gaap:DebtSecuritiesMembertslx:OtherMember2022-12-310001508655tslx:AxonifyIncMembertslx:EquityAndOtherInvestmentsMembertslx:ClassAOneUnitsMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMembertslx:BlueSnapIncMember2022-12-310001508655us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2020-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:OilGasAndConsumableFuelsMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:TRPAssetsLLCMember2022-12-310001508655tslx:EMSLinqIncMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2022-12-310001508655us-gaap:AssetPledgedAsCollateralMember2021-12-310001508655tslx:NewportParentHoldingsLPMembertslx:ClassATwoUnitsMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:MagnetiteCloLtdSeriesTwoThousandTwentyOneThirtyAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2022-08-020001508655tslx:SecondLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2021-12-310001508655tslx:TwentyTwentyFourNotesMember2022-01-012022-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:CifcCloLtdSeriesTwoThousandEighteenThreeAMember2022-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:MurchisonOilAndGasLlcMember2022-01-012022-12-310001508655tslx:SubordinatedNoteDueSeptemberTwoThousandTwentySixMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:AmericanAchievementCorpMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMembertslx:MDAmericaEnergyLimitedLiabilityCompanyMember2021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:LithiumTechnologiesLLCMembertslx:InternetServicesMember2021-01-012021-12-3100015086552022-06-300001508655us-gaap:FairValueInputsLevel3Member2022-01-012022-12-310001508655us-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:PikesPeakCloSeriesTwoThousandTwentyOneNineAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueNovemberTwoThousandTwentySevenMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:Project44IncMemberus-gaap:DebtSecuritiesMembertslx:TransportationMember2021-12-310001508655tslx:TwoThousandTwentyThreeNotesMembersrt:MaximumMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapThreeMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeLiabilitiesInterestRateSwapOneMember2021-12-310001508655us-gaap:DebtSecuritiesMember2021-12-310001508655tslx:OfficeProductsMember2021-12-310001508655tslx:CommunicationsMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:IntelePeerHoldingsIncMember2021-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2021-12-310001508655tslx:SpecialDividendMember2020-02-192020-02-190001508655tslx:StructuredCreditMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMember2021-01-012021-12-310001508655tslx:HornetsecurityHoldingGmbhMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueNovemberTwoThousandTwentyNineMember2022-01-012022-12-310001508655tslx:TradingScreenIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:BayshoreIntermediate2LPMembertslx:RevolverMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:DestinySolutionsParentHoldingCompanyMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2022-01-012022-12-310001508655tslx:BiohavenPharmaceuticalsIncMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMembertslx:PharmaceuticalsMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:BCTOAcePurchaserIncMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:AresLoanFundingILtdSeriesTwoThousandTwentyOneAlfaClassEMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapTenMember2021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeAssetInterestRateSwapOneMember2022-12-310001508655tslx:LithiumTechnologiesLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienRevolvingLoanDueJanuaryTwoThousandAndTwentyFourMembertslx:InternetServicesMember2022-12-310001508655tslx:InterestRateSwapEightMember2022-01-012022-12-310001508655srt:PartnershipInterestMembertslx:EducationMembertslx:RMCFIVCIVXXXVLPMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:IRGSEHoldingCorpMembertslx:FirstLienRevolvingLoanJuneTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-01-012021-12-310001508655tslx:OfficeProductsMemberus-gaap:DebtSecuritiesMembertslx:ABLFILOTermLoanMembertslx:USRParentIncMember2021-01-012021-12-310001508655us-gaap:DebtSecuritiesMembertslx:MitnickCorporatePurchaserIncMembertslx:BusinessServicesMembertslx:FirstLienLoanDueMayTwoThousandTwentyNineMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:ConvertibleNotesDueJuneTwoThousandTwentySevenMembertslx:HumanResourceSupportServicesMembertslx:EmploymentHeroHoldingsPtyLtdMember2021-01-012021-12-310001508655tslx:OtherMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:ClinicientIncMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourThreeMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:SprinklrIncMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655country:AU2022-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:CanadianDollarOfferedRateMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMember2021-12-310001508655tslx:CommonUnitsMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2022-01-012022-12-310001508655tslx:RevolverMembertslx:ClinicientIncMember2021-12-310001508655tslx:ChemicalsMember2022-12-310001508655tslx:SpecialDividendMember2021-11-020001508655tslx:MezzanineDebtInvestmentsMember2021-12-310001508655us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveOneMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:SecuredOvernightFinancingRateMembertslx:FirstLienLoanDueJanuaryTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:LithiumTechnologiesLLCMembertslx:InternetServicesMember2022-12-310001508655tslx:ReliaQuestLLCMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMembertslx:ClassAOneUnitsMember2022-12-310001508655tslx:CarvalCloIiiLtdSeriesTwoThousandNineteenTwoAMembertslx:StructuredProductDueJulyTwoThousandThirtyTwoMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:CordanceOperationsLlcMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:EDBParentLLCMembertslx:DelayedDrawMember2022-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFourMembertslx:IntelePeerHoldingsIncMember2022-12-310001508655us-gaap:SeriesDPreferredStockMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:PianoSoftwareIncMembertslx:SecuredOvernightFinancingRateMembertslx:FirstLienLoanDueFebruaryTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-12-310001508655tslx:AresCloLtdSeriesTwoThousandTwentyOneFiftyNineAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyFourMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:DerivativeLiabilitiesInterestRateSwapThreeMember2021-12-310001508655tslx:ExtraHopNetworksIncMembertslx:DelayedDrawMember2022-12-310001508655tslx:SeriesAPreferredUnitsMembertslx:ClearCompanyLLCMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:FirstLienLoanDueJuneTwoThousandTwentySixOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2022-01-012022-12-310001508655tslx:DestinySolutionsParentHoldingCompanyMembertslx:DelayedDrawMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesDPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:InterestRateSwapNineMember2021-01-012021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveOneMember2022-12-3100015086552017-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:AssetValuationWaterfallMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2016-01-012016-12-310001508655tslx:BCTOAcePurchaserIncMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2022-01-012022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:HotelGamingAndLeisureMembertslx:ClassCOneUnitsMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienTermLoanDueDecemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:EmploymentHeroHoldingsPtyLtdMembertslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentySixMembertslx:PassportLabsIncMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:FirstLienDebtInvestmentsMember2021-01-012021-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2022-12-310001508655tslx:HornetsecurityHoldingGmbhMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:EuroInterbankOfferRateMembertslx:FirstLienLoanDueNovemberTwoThousandTwentyNineMember2022-12-310001508655tslx:FutureRealizedCapitalGainsPriorToAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2020-03-312020-03-310001508655tslx:IbisIntermediateCoMembertslx:FirstLienLoanDueMayTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductMembertslx:BainCapitalCreditCLOLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:SouthMember2021-12-310001508655tslx:IRGSEHoldingCorpMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-12-310001508655tslx:SeriesCOnePreferredSharesMembertslx:PianoSoftwareIncMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:IlluminateEducationIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyTwoMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:DelayedDrawAndMembershipInterestMembertslx:TRPAssetsLLCMember2022-12-310001508655tslx:DelayedDrawMembertslx:IntelePeerHoldingsIncMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapNineMember2022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-01-012022-12-3100015086552020-09-300001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMember2022-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:MississippiResourcesLLCMember2021-12-310001508655tslx:ExtraHopNetworksIncMembertslx:DelayedDrawMember2021-12-310001508655tslx:SpecialDividendTwoMember2020-02-192020-02-190001508655tslx:FirstLienTermLoanDueDecemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:EmploymentHeroHoldingsPtyLtdMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienRevolvingLoanOctoberTwoThousandTwentyFiveMembertslx:DaySmartHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentySixNotesMember2022-01-012022-12-310001508655tslx:SMATechnologiesHoldingsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:WindRiverCloLtdSeriesTwoThousandEighteenThreeAMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:GoldentreeCloLtdSeriesTwoThousandTwentySevenAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueAprilTwoThousandThirtyFourMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2020-01-012020-12-310001508655tslx:SeriesCOnePreferredSharesMembertslx:PianoSoftwareIncMembertslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SubordinatedNoteDueSeptemberTwoThousandTwentySixMembertslx:AmericanAchievementCorpMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:AdministrationAgreementMember2021-11-012021-11-300001508655tslx:FirstLienLoanDueAugustTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-01-012021-12-310001508655us-gaap:InterestRateSwapMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMembertslx:BlueSnapIncMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMember2022-01-012022-12-310001508655tslx:BaseDividendMember2021-05-042021-05-040001508655tslx:FirstLienRevolvingLoanMayTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:ClinicientIncMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:TwoThousandTwentyThreeAndTwentyFourAndTwentySixNotesMember2020-01-012020-12-310001508655tslx:FirstLienLoanDueJulyTwentyTwentyFourMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:LucidworksIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655tslx:SupplementalDividendMember2022-02-172022-02-170001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapSixMember2022-12-310001508655tslx:StructuredCreditMembertslx:DrydenSeniorLoanFundSeriesTwoThousandEighteenFiftyFiveAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655country:DE2022-12-310001508655tslx:Octagon57LlcSeries20211AMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:ClassAUnitsMembertslx:NeuintelLLCMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourFourMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:BankBillSwapBidRateMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:AcceoSolutionsIncMember2022-01-012022-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:CrownPointCloLtdSeriesTwoThousandTwentyOneTenAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-01-012022-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:MurchisonOilAndGasLlcMember2022-12-310001508655tslx:WarrantTwoMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyThreeOneMember2021-12-310001508655tslx:EducationMembertslx:MembershipInterestMembertslx:Astra2LHoldingsIILLCMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BedBathAndBeyondIncMembertslx:AblFiloTermLoanDueAugustTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerControlledMembertslx:MississippiResourcesLLCMember2022-01-012022-12-310001508655tslx:SupplementalDividendMember2020-02-192020-02-190001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMemberus-gaap:HealthcareSectorMembertslx:IntegratedPracticeSolutionsIncMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductOneMembertslx:CarlyleGlobalMarketStrategiesCLOLtdMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveOneMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:MDAmericaEnergyLLCMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-12-310001508655tslx:StructuredProductTwoMembertslx:StructuredCreditMembertslx:CarlyleGlobalMarketStrategiesCLOLtdMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:PrimePayIntermediateLLCMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixFourMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapTenMember2021-01-012021-12-310001508655tslx:IlluminateEducationIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyTwoMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:DelayedDrawMembertslx:VerdadResourcesIntermediateHoldingsLLCMember2021-12-310001508655tslx:SecondLienDebtInvestmentsMember2022-01-012022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2021-12-310001508655tslx:ChemicalsMembertslx:FirstLienLoanOneDueSeptemberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:ErlingLuxBidcoSarlMember2022-12-310001508655tslx:MarketingServicesMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixOneMembertslx:HumanResourceSupportServicesMembertslx:EmploymentHeroHoldingsPtyLtdMember2021-12-310001508655tslx:PrimePayIntermediateLLCMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixFourMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:StructuredProductDueMayTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:AmericanMoneyManagementCorpCloLtdSeriesTwoThousandSixteenEighteenAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveOneMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:SterlingOvernightInterbankAverageRateMembertslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:RevolvingCreditFacilityMember2022-03-310001508655srt:MaximumMembertslx:TwoThousandTwentyFourNotesMember2020-01-012020-12-310001508655tslx:BaseDividendMember2021-08-030001508655tslx:EMSLinqIncMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2022-01-012022-12-310001508655tslx:OilGasAndConsumableFuelsMembersrt:PartnershipInterestMembertslx:EquityAndOtherInvestmentsMembertslx:TRPAssetsLLCMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyMembertslx:OctagonInvestmentPartnersThirtyEightLtdSeriesTwoThousandEighteenOneAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyThreeOneMember2021-01-012021-12-310001508655tslx:AblFirstLienLoanDueAugustTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:DesignerBrandsIncMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwoThousandTwentySixNotesMember2021-12-310001508655tslx:TangoManagementConsultingLLCMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:ProjectPIntermediate2LLCMembertslx:ABLFILOTermLoanDueMayTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:ReliaQuestHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMembertslx:BusinessServicesMember2021-12-310001508655tslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveTwoMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2020-12-310001508655tslx:IRGSEHoldingCorpMembertslx:ClassAUnitsMembertslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMemberus-gaap:HealthcareSectorMembertslx:IntegratedPracticeSolutionsIncMember2022-01-012022-12-310001508655tslx:AresLoanFundingILtdSeriesTwoThousandTwentyOneAlfaClassEMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:TreasuryStockMember2020-12-310001508655tslx:TwoThousandTwentySixNotesMember2022-12-310001508655tslx:FirstLienRevolvingLoanDueOctoberTwoThousandAndTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueAprilTwoThousandThirtyThreeMembertslx:StructuredCreditMembertslx:RRLtdSeriesTwoThousandTwentyEightAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapSixMember2021-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapThreeMember2022-12-310001508655us-gaap:FinancialServicesSectorMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:EMSLinqIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:CrunchtimeInformationSystemsIncMembertslx:DelayedDrawMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:ClassAUnitsMembertslx:HotelGamingAndLeisureMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:OfficeProductsMembertslx:ABLFILOTermLoanMemberus-gaap:DebtSecuritiesMembertslx:USRParentIncMember2021-12-310001508655tslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMembertslx:TRPAssetsLLCMember2022-01-012022-12-3100015086552022-01-012022-12-310001508655tslx:DerivativeAssetInterestRateSwapNineMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:BCTOAcePurchaserIncMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:IbisIntermediateCoMembertslx:DelayedDrawMember2021-12-310001508655tslx:AutomotiveMembertslx:CarlstarGroupLLCMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2022-12-310001508655tslx:AxonifyIncMembertslx:EquityAndOtherInvestmentsMembertslx:ClassAOneUnitsMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:InvestmentAdvisoryAgreementMembertslx:RealizedCapitalGainsAccruedBeginningAprilFirstTwoThousandFourteenMember2011-04-152011-04-150001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2018-01-012018-12-310001508655tslx:CopperBidcoLLCMembertslx:TrustCertificatesTwoMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655us-gaap:WarrantMembertslx:ValantMedicalSolutionsIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:RevolvingCreditsFacilitiesMember2019-01-012019-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:SecondLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:KyribaCorpMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:CarvalCloIiiLtdSeriesTwoThousandNineteenTwoAMembertslx:StructuredProductDueJulyTwoThousandThirtyTwoMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:ForeScoutTechnologiesIncMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:EuroInterbankOfferRateMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveOneMember2022-12-310001508655us-gaap:RevolvingCreditFacilityMember2022-04-250001508655tslx:BaseDividendMember2022-11-012022-11-010001508655tslx:RisksRelatedToEconomicConditionsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMembertslx:ExtraHopNetworksIncMember2022-12-310001508655us-gaap:AdditionalPaidInCapitalMember2020-01-012020-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-12-310001508655us-gaap:CommonStockMember2021-01-012021-12-310001508655tslx:DelayedDrawMembertslx:AlphaMidcoIncMember2021-12-3100015086552021-01-012021-03-310001508655tslx:FirstLienLoanDueNovemberTwoThousandTwentySevenMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:Project44IncMemberus-gaap:DebtSecuritiesMembertslx:TransportationMember2022-12-310001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:BswiftLlcMembertslx:FirstLienLoanDueNovemberTwoThousandTwentyEightMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:EatonCloLtdSeriesTwoThousandFifteenOneAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2022-12-310001508655tslx:IRGSEHoldingCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2022-01-012022-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:SMPAHoldingsLLCMembertslx:CommonUnitsMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFourMemberus-gaap:DebtSecuritiesMembertslx:LithiumTechnologiesLLCMembertslx:InternetServicesMember2022-01-012022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:ExtraHopNetworksIncMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2022-01-012022-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2017-01-012017-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:AcceoSolutionsIncMembertslx:CanadianDollarOfferedRateMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PrimeRevenueIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapSixMember2021-01-012021-12-310001508655tslx:OfficeProductsMembertslx:ABLFILOTermLoanDueAprilTwoThousandTwentySevenMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:USRParentIncMember2022-12-3100015086552020-06-300001508655us-gaap:DebtSecuritiesMember2022-12-310001508655tslx:CommunicationsMembertslx:ClassAUnitsMembertslx:CeltraTechnologiesIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesDPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapEightMember2022-01-012022-12-310001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJanuaryTwoThousandTwentyEightMembertslx:ElysianFincoLtdMembertslx:HumanResourceSupportServicesMember2022-12-3100015086552020-04-012020-06-300001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixMembertslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:DestinySolutionsParentHoldingCompanyMember2021-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:DebtSecuritiesMembertslx:CarisLifeSciencesIncMemberus-gaap:HealthcareSectorMember2021-01-012021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:MurchisonOilAndGasLlcMembertslx:ClassCOneUnitsMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtySixMembertslx:EquityAndOtherInvestmentsMembertslx:WindRiverCloLtdSeriesTwoThousandSeventeenOneAMember2022-01-012022-12-310001508655tslx:TwentyTwentyFourNotesMember2021-01-012021-12-310001508655tslx:BswiftLlcMembertslx:ClassAOneUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:OilGasAndConsumableFuelsMember2021-12-310001508655tslx:AdministrationAgreementMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdviserMember2021-01-012021-12-310001508655us-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapFourMember2021-12-310001508655tslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:IbisUSBlockerCoMember2022-12-310001508655tslx:OfficeProductsMembertslx:ABLFILOTermLoanDueAprilTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:USRParentIncMember2022-12-310001508655tslx:FirstLienLoanDueJulyTwentyTwentyFourMembertslx:LucidworksIncMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-01-012021-12-310001508655tslx:FinancialServicesMembertslx:AvidXchangeIncMemberus-gaap:CommonStockMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-3100015086552015-08-042015-08-040001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMembertslx:ExtraHopNetworksIncMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeAssetInterestRateSwapEightMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:BenefitStreetPartnersCloLtdSeriesTwoThousandFifteenEightAMembertslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapSixMember2022-01-012022-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapNineMember2022-12-310001508655country:AU2021-12-310001508655tslx:WestMember2021-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:MidoceanCreditCloLtdSeries20189AMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:SecondLienDebtInvestmentsMember2021-12-310001508655tslx:ReliaQuestLLCMembertslx:BusinessServicesMembertslx:ClassAOneUnitsMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-12-310001508655tslx:StructuredProductDueJuneTwoThousandThirtyOneMembertslx:WhiteboxCloILtdSeriesTwoThousandTwentyTwoAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BusinessServicesMember2022-12-310001508655tslx:ClassAUnitsMembertslx:NeuintelLLCMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-3100015086552022-01-012022-03-310001508655tslx:DerivativeLiabilitiesInterestRateSwapOneMember2022-12-310001508655tslx:StructuredCreditMembertslx:StructuredProductDueJanuaryTwoThousandThirtySevenMembertslx:GulfStreamMeridianSeriesTwoThousandTwentyOneSixAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:CommunicationsMembertslx:FirstLienLoanDueNovemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:CeltraTechnologiesIncMember2021-12-310001508655tslx:RevolvingCreditsFacilitiesMember2020-01-012020-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-310001508655tslx:CifcCloLimitedSeriesTwoThousandAndTwentyOneFourAMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyThreeMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:AlphaMidcoIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Member2022-12-3100015086552021-03-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentySixMembertslx:AxonifyIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:IRGSEHoldingCorpMembertslx:FirstLienRevolvingLoanJuneTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-12-310001508655tslx:Project44IncMembertslx:DelayedDrawMember2022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:AsgIiLlcMembertslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:TradingScreenIncMembertslx:FirstLienLoanDueAprilTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2022-01-012022-12-310001508655us-gaap:ShortMembertslx:DerivativeLiabilitiesInterestRateSwapThreeMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PianoSoftwareIncMembertslx:FirstLienLoanDueFebruaryTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655tslx:RevolvingCreditFacilityMaturityOnJanuary312025Member2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapSixMember2021-12-310001508655tslx:FirstLienRevolvingLoanDueOctoberTwoThousandAndTwentySevenMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMembertslx:BayshoreIntermediate2LPMember2022-12-310001508655tslx:DyeDurhamLtdMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeAssetInterestRateSwapFourMember2021-12-310001508655tslx:DerivativeAssetInterestRateSwapFourMember2021-12-310001508655tslx:FirstLienRevolvingLoanOctoberTwoThousandTwentyTwoMembertslx:SecuredOvernightFinancingRateMembertslx:LithiumTechnologiesLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-3100015086552022-10-012022-12-310001508655tslx:VoyaCloLtdSeries20183AMembertslx:StructuredCreditMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BenefitStreetPartnersCloLtdSeriesTwoThousandFifteenBRMembertslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyEightMembertslx:OutsystemsLuxcoMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2020-02-050001508655tslx:SecondLienDebtInvestmentsMember2022-12-310001508655tslx:ParkAvenueInstitutionalAdvisersCloLtdSeriesTwoThousandEighteenOneAMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:BusinessServicesMember2021-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2018-01-012018-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixOneMembertslx:HumanResourceSupportServicesMembertslx:EmploymentHeroHoldingsPtyLtdMember2021-01-012021-12-310001508655tslx:TangoManagementConsultingLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel2Member2022-12-310001508655tslx:TwoThousandTwentySixNotesMember2021-02-032021-02-030001508655tslx:SecuredOvernightFinancingRateMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:BtrsHoldingsIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyEightMember2022-12-310001508655tslx:TwentyTwentySixNotesMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueDecemberTwentyTwentyFiveMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:Project44IncMembertslx:DelayedDrawMember2021-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:BattalionCloLtdSeriesTwoThousandTwentyOneTwentyOneAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:AutomotiveMembertslx:CarlstarGroupLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2022-01-012022-12-310001508655tslx:SpecialDividendMember2021-02-172021-02-170001508655tslx:SecondLienDebtInvestmentsMember2021-01-012021-12-310001508655us-gaap:RetainedEarningsMember2019-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:HomecareSoftwareSolutionsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMember2021-12-310001508655tslx:BaseDividendMember2022-05-032022-05-030001508655tslx:DelayedDrawAndRevolverMembertslx:KyribaCorpMember2021-12-310001508655tslx:TradingScreenIncMembertslx:FirstLienLoanDueAprilTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2021-12-310001508655tslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:PikesPeakCloSeriesTwoThousandTwentyOneNineAMember2022-12-310001508655tslx:WarrantTwoMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:IbisUSBlockerCoMember2021-12-310001508655tslx:InterestRateSwapFourMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:GTreasurySSLLCMembertslx:FirstLienLoanDueAprilTwoThousandTwentyThreeMember2021-12-310001508655tslx:BearOpCoLLCMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMember2022-12-310001508655tslx:StructuredCreditMembertslx:EatonCloLtdSeriesTwoThousandFifteenOneAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2022-12-310001508655tslx:SecondLienDebtInvestmentsMember2020-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMemberus-gaap:HealthcareSectorMembertslx:IntegratedPracticeSolutionsIncMember2021-12-310001508655tslx:AsgIiLlcMembertslx:DelayedDrawMember2022-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMember2022-01-012022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFourMembertslx:BlueSnapIncMember2022-12-310001508655tslx:AdministrationAgreementMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdviserMember2022-01-012022-12-310001508655us-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655tslx:ParkAvenueInstitutionalAdvisersCloLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:ProjectPIntermediate2LLCMembertslx:ABLFILOTermLoanDueMayTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:SecuredOvernightFinancingRateMembertslx:PrimePayIntermediateLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2018-01-012018-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFourOneMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMembertslx:VerdadResourcesIntermediateHoldingsLLCMember2021-12-310001508655tslx:ClassAUnitsMembertslx:ValantMedicalSolutionsIncMemberus-gaap:HealthcareSectorMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:LetterOfCreditMember2022-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMember2021-01-012021-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:CanadianDollarOfferedRateMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMember2022-12-310001508655srt:ObligorGroupMemberus-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2022-12-310001508655tslx:SMPAHoldingsLLCMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-12-310001508655tslx:SupplementalDividendMember2020-02-190001508655us-gaap:RetainedEarningsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:AcceoSolutionsIncMember2021-12-310001508655tslx:FirstLienLoanDueDecemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:BankBillSwapBidRateMembertslx:EmploymentHeroHoldingsPtyLtdMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:EMSLinqIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFourOneMembertslx:OilGasAndConsumableFuelsMemberus-gaap:DebtSecuritiesMembertslx:VerdadResourcesIntermediateHoldingsLLCMember2021-01-012021-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:MidoceanCreditCloLtdSeries20189AMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:AdministrationAgreementMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdviserMember2020-01-012020-12-310001508655tslx:InterestRateSwapFiveMember2022-01-012022-12-310001508655tslx:InterestRateSwapEightMember2021-01-012021-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMembertslx:LeantaasHoldingsIncMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655tslx:ManufacturingMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:AvalaraIncMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TradingScreenIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:NetwrixCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyNineMembertslx:BusinessServicesMember2022-01-012022-12-310001508655tslx:JeffersonMillCloLtdSeriesTwoThousandFifteenOneAMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeAssetInterestRateSwapFourMember2022-12-310001508655tslx:FinancialServicesMembertslx:ClassAUnitsMembertslx:TradingScreenIncMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwoThousandTwentyFourNotesMember2021-12-310001508655tslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:EatonCloLtdSeriesTwoThousandTwentyOneAMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:MDAmericaEnergyLLCMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-01-012022-12-310001508655tslx:AmericanAchievementCorpMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655us-gaap:FairValueInputsLevel3Member2021-01-012021-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveMember2022-12-310001508655tslx:MoranFoodsLLCMemberus-gaap:DebtSecuritiesMembertslx:ABLFILOTermLoanDueAprilTwoThousandTwentyFourMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:RevolvingCreditFacilityMaturityOnJanuary312025Member2022-12-310001508655us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-01-012021-12-310001508655tslx:TradingScreenIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PassportLabsIncMember2021-12-310001508655us-gaap:PrimeRateMembertslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienRevolvingLoanDecemberTwoThousandTwentySixMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ReliaQuestHoldingsLLCMember2022-12-310001508655tslx:TwentyTwentyFourNotesMember2019-01-012019-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredCreditMembertslx:DrydenSeniorLoanFundSeriesTwoThousandEighteenFiftyFiveAMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:CommunicationsMemberus-gaap:SeriesCPreferredStockMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:CifcCloLimitedSeriesTwoThousandAndTwentyOneFourAMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyThreeMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FinancialServicesMembertslx:ClassAUnitsMembertslx:TradingScreenIncMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeAssetInterestRateSwapThreeMember2022-12-310001508655tslx:WarrantOneMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueMarchTwoThousandTwentyNineMembertslx:TIBCOSoftwareIncMember2022-01-012022-12-310001508655tslx:FinancialServicesMembertslx:ClassAUnitsMembertslx:TradingScreenIncMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:EducationMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2019-11-012019-11-300001508655tslx:SupplementalDividendMember2020-11-040001508655us-gaap:TreasuryStockMember2019-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2022-04-250001508655tslx:EMSLinqIncMembertslx:EducationMembertslx:ClassBUnitsMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DelayedDrawAndMembershipInterestMembertslx:TRPAssetsLLCMember2021-12-310001508655tslx:TwentyTwentyThreeNotesMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapTwoMember2021-12-310001508655tslx:SubordinatedNoteDueSeptemberTwoThousandTwentySixMembertslx:AmericanAchievementCorpMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2021-12-310001508655tslx:BaseDividendMember2020-08-040001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StructuredProductDueOctoberTwoThousandThirtyFourMembertslx:StructuredCreditMembertslx:PikesPeakCloSeriesTwoThousandTwentyOneNineAMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveTwoMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMember2021-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredCreditInvestmentsMember2021-12-310001508655tslx:OilGasAndConsumableFuelsMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:MississippiResourcesLLCMember2021-01-012021-12-310001508655tslx:SupplementalDividendMember2021-02-170001508655tslx:FirstLienLoanDueMayTwoThousandTwentyFourFiveMembertslx:PayScaleHoldingsIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-3100015086552021-04-012021-06-300001508655tslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandEighteenOneAMembertslx:StructuredCreditMembertslx:StructuredProductDueAprilTwoThousandThirtyOneMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655us-gaap:RevolvingCreditFacilityMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueJulyTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:CordanceOperationsLlcMembertslx:RetailAndConsumerProductsMember2022-12-310001508655us-gaap:ShortMembertslx:DerivativeLiabilitiesInterestRateSwapTwoMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:EMSLinqIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2021-12-3100015086552020-03-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TangoManagementConsultingLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMembertslx:RetailAndConsumerProductsMember2021-12-3100015086552020-12-310001508655tslx:ChemicalsMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentyEightMembertslx:ErlingLuxBidcoSarlMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySixMembertslx:NeuintelLLCMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2017-01-012017-12-310001508655tslx:TangoManagementConsultingLLCMembertslx:DelayedDrawAndRevolverMember2021-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:SecondLienLoanDueOctoberTwoThousandTwentyNineMembertslx:AstraAcquisitionCorpMember2022-01-012022-12-310001508655tslx:EducationMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:CommunicationsMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655country:CA2022-12-310001508655tslx:HotelGamingAndLeisureMember2021-12-310001508655tslx:CommunicationsMembertslx:WarrantOneMembertslx:IntelePeerHoldingsIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveMembertslx:InformationClearinghouseLLCAndMSMarketServiceLLCMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655us-gaap:WarrantMembertslx:PharmaceuticalsMembertslx:TherapeuticsMDIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:BayshoreIntermediate2LPMembertslx:InternetServicesMember2022-12-310001508655tslx:SeriesAPreferredUnitsMembertslx:ClearCompanyLLCMembertslx:EquityAndOtherInvestmentsMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:StructuredCreditMembertslx:CarlyleGlobalMarketStrategiesCLOLtdSeriesTwoThousandSeventeenFourAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2021-01-012021-12-310001508655tslx:TangoManagementConsultingLLCMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2021-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapSevenMember2021-12-310001508655tslx:AmericanAchievementCorpMembertslx:ClassAUnitsMembertslx:EquityAndOtherInvestmentsMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveOneMembertslx:DaySmartHoldingsLLCMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapOneMember2021-12-310001508655us-gaap:FairValueInputsLevel1Member2022-12-310001508655tslx:ConvertibleNoteDueSeptemberTwoThousandTwentyThreeMemberus-gaap:DebtSecuritiesMemberus-gaap:HealthcareSectorMembertslx:CarisLifeSciencesIncMember2021-12-310001508655tslx:MezzanineDebtInvestmentsMember2021-01-012021-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-01-012022-12-310001508655srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembertslx:EquityAndOtherInvestmentsMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourFourMembertslx:ModernHireIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:StewartParkCloLtdSeriesTwoThousandFifteenOneAMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2022-12-310001508655tslx:CommunicationsMembertslx:ClassAUnitsMembertslx:CeltraTechnologiesIncMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:DerivativeAssetInterestRateSwapFiveMember2021-12-310001508655us-gaap:WarrantMembertslx:FinancialServicesMembertslx:EquityAndOtherInvestmentsMembertslx:PassportLabsIncMember2022-01-012022-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:ExtraHopNetworksIncMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2021-01-012021-12-310001508655tslx:SouthMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PassportLabsIncMember2022-12-310001508655tslx:ReliaQuestHoldingsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-01-012021-12-310001508655tslx:EMSLinqIncMembertslx:RevolverMember2021-12-310001508655tslx:HomecareSoftwareSolutionsLLCMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentySixMemberus-gaap:HealthcareSectorMember2021-12-310001508655us-gaap:RevolvingCreditFacilityMember2022-12-310001508655tslx:InterestRateSwapOneMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:PageUpPeopleLtdMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentyFiveTwoMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:StructuredProductDueJulyTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:CifcCloLtdSeriesTwoThousandEighteenThreeAMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:ABLFILOTermLoanDueMayTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:NinetyNineCentsOnlyStoresLLCMembertslx:RetailAndConsumerProductsMember2021-12-310001508655tslx:IbisIntermediateCoMemberus-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueMayTwoThousandTwentySevenMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:CifcCloLimitedSeriesTwoThousandAndTwentyOneFourAMembertslx:StructuredCreditMembertslx:StructuredProductDueJulyTwoThousandThirtyThreeMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:EMSLinqIncMembertslx:EducationMembertslx:ClassBUnitsMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:BaseDividendMember2020-02-190001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMembertslx:FirstLienRevolvingLoanAprilTwoThousandTwentyFiveMember2021-01-012021-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJanuaryTwoThousandTwentyEightMembertslx:ElysianFincoLtdMembertslx:HumanResourceSupportServicesMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueMarchTwoThousandTwentySixMembertslx:OmnigoSoftwareLLCMemberus-gaap:DebtSecuritiesMembertslx:OtherMember2022-01-012022-12-310001508655tslx:CrunchtimeInformationSystemsIncMembertslx:SecuredOvernightFinancingRateMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJuneTwoThousandTwentyEightMembertslx:InternetServicesMember2022-12-310001508655tslx:FinancialServicesMembertslx:AvidXchangeIncMemberus-gaap:CommonStockMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655us-gaap:ShortMembertslx:DerivativeAssetInterestRateSwapThreeMember2022-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapTwoMember2022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2021-12-310001508655tslx:NortheastMember2021-12-310001508655tslx:RisksRelatedToOurSecuritiesMember2022-01-012022-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMember2022-01-012022-12-310001508655tslx:AlphaMidcoIncMembertslx:FirstLienLoanDueAugustTwoThousandTwentyFiveMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueJuneTwoThousandTwentySixOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:JonasCollectionsAndRecoveryIncMember2021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:LongMembertslx:DerivativeLiabilitiesInterestRateSwapThreeMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueAprilTwoThousandTwentySixMembertslx:PassportLabsIncMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:ExtraHopNetworksIncMembertslx:FirstLienLoanDueJulyTwoThousandTwentySevenMember2022-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655tslx:CedarFundingCloLtdSeriesTwoThousandEighteenSevenAMembertslx:StructuredProductDueJanuaryTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655us-gaap:FinancialServicesSectorMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:VoyaCloLtdSeries20183AMembertslx:StructuredProductDueOctoberTwoThousandThirtyOneMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:EMSLinqIncMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenMembertslx:EducationMemberus-gaap:DebtSecuritiesMember2021-01-012021-12-310001508655us-gaap:LongMembertslx:DerivativeAssetInterestRateSwapElevenMember2021-12-310001508655tslx:FirstLienLoanDueMayTwothousandTwentySixOneMembertslx:AxonifyIncMemberus-gaap:DebtSecuritiesMembertslx:HumanResourceSupportServicesMember2021-12-310001508655tslx:BedBathAndBeyondIncMembertslx:AblFiloTermLoanDueAugustTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMembertslx:RetailAndConsumerProductsMember2022-01-012022-12-310001508655tslx:TwoThousandTwentySixNotesMember2021-01-012021-12-310001508655tslx:AmericanAchievementCorpMembertslx:RevolverMember2021-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2020-12-310001508655tslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-01-260001508655tslx:CommonUnitsMembertslx:InternetServicesMembertslx:BayshoreIntermediate2LPMembertslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwentyTwentyFourNotesMember2019-11-302019-11-300001508655us-gaap:CommonStockMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueMayTwoThousandTwentyEightMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:IbisUSBlockerCoMember2021-12-310001508655tslx:DyeDurhamLtdMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:MDAmericaEnergyLLCMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2020-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:WideOrbitIncMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentyFiveMembertslx:BusinessServicesMember2021-12-310001508655tslx:DyeDurhamCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMembertslx:FirstLienLoanDueDecemberTwoThousandTwentySevenOneMember2021-12-310001508655tslx:BaseDividendMember2021-02-170001508655tslx:IRGSEHoldingCorpMembertslx:FirstLienLoanDueJuneTwoThousandTwentyTwoMemberus-gaap:DebtSecuritiesMembertslx:HotelGamingAndLeisureMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2022-12-310001508655us-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:GTreasurySSLLCMembertslx:FirstLienLoanDueAprilTwoThousandTwentyThreeMember2021-01-012021-12-310001508655tslx:InternetServicesMembertslx:EquityAndOtherInvestmentsMember2022-12-310001508655tslx:StructuredCreditMembertslx:EatonCloLtdSeriesTwoThousandFifteenOneAMembertslx:EquityAndOtherInvestmentsMembertslx:StructuredProductDueJanuaryTwoThousandThirtyMember2022-01-012022-12-310001508655tslx:MitnickTaAggregatorLpMembertslx:MembershipInterestMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:EducationMemberus-gaap:DebtSecuritiesMembertslx:SecondLienLoanDueOctoberTwoThousandTwentyNineMembertslx:AstraAcquisitionCorpMember2022-12-310001508655tslx:FirstLienLoanDueJanuaryTwoThousandTwentyFourMembertslx:LithiumTechnologiesLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655tslx:PrimePayIntermediateLLCMembertslx:DelayedDrawMember2021-12-310001508655tslx:SouthwickParkCloLtdSeries20194AMembertslx:StructuredProductDueJulyTwoThousandThirtyTwoMembertslx:StructuredCreditMembertslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:FirstLienLoanDueOctoberTwoThousandTwentyTwoMembertslx:LithiumTechnologiesLLCMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2021-12-310001508655tslx:LeantaasHoldingsIncMembertslx:DelayedDrawMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Membertslx:FirstLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2021-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2022-01-012022-12-310001508655tslx:FirstLienLoanDueAprilTwoThousandTwentyFiveOneMemberus-gaap:FinancialServicesSectorMemberus-gaap:DebtSecuritiesMembertslx:KyribaCorpMember2021-01-012021-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TradingScreenIncMemberus-gaap:FinancialServicesSectorMembertslx:FirstLienLoanDueAprilTwoThousandTwentySevenMemberus-gaap:DebtSecuritiesMember2021-12-310001508655us-gaap:DebtSecuritiesMembertslx:ClinicientIncMembertslx:FirstLienLoanDueMayTwoThousandTwentyFourThreeMemberus-gaap:HealthcareSectorMember2021-01-012021-12-310001508655us-gaap:DebtSecuritiesMembertslx:BswiftLlcMembertslx:FirstLienLoanDueNovemberTwoThousandTwentyEightMembertslx:HumanResourceSupportServicesMember2022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:TwoThousandTwentyThreeNotesMember2022-01-012022-12-310001508655us-gaap:LondonInterbankOfferedRateLIBORMembertslx:FirstLienLoanDueSeptemberTwoThousandTwentySixMembertslx:NetwrixCorpMemberus-gaap:DebtSecuritiesMembertslx:BusinessServicesMember2021-12-310001508655tslx:TwentyTwentyThreeNotesMember2022-12-310001508655tslx:TwentyTwentySixNotesMember2022-01-012022-12-310001508655tslx:DyeDurhamLtdMemberus-gaap:CommonStockMembertslx:BusinessServicesMembertslx:EquityAndOtherInvestmentsMember2021-01-012021-12-310001508655tslx:DerivativeLiabilitiesInterestRateSwapOneMember2021-01-012021-12-310001508655tslx:DerivativeAssetInterestRateSwapTwoMember2021-01-012021-12-310001508655tslx:SMATechnologiesHoldingsLLCMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:InternetServicesMember2022-12-310001508655us-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueOctoberTwoThousandTwentyFiveFourMembertslx:WorkwellAcquisitionCoMembertslx:HumanResourceSupportServicesMember2021-01-012021-12-310001508655tslx:ChemicalsMembertslx:FirstLienLoanOneDueSeptemberTwoThousandTwentyEightMemberus-gaap:DebtSecuritiesMembertslx:SterlingOvernightInterbankAverageRateMembertslx:ErlingLuxBidcoSarlMember2022-12-310001508655us-gaap:ShortMembertslx:DerivativeLiabilitiesInterestRateSwapOneMember2021-12-310001508655tslx:WideOrbitIncMemberus-gaap:DebtSecuritiesMembertslx:FirstLienLoanDueJulyTwoThousandTwentyFiveMembertslx:BusinessServicesMember2021-01-012021-12-31