3.24.0.1 html 355 324 1 true 89 0 false 8 false false R1.htm 0000001 - Document - Cover Sheet http://fskkrcapitalcorp.com/role/Cover Cover Cover 1 false false R2.htm 0000002 - Document - Audit Information Sheet http://fskkrcapitalcorp.com/role/AuditInformation Audit Information Cover 2 false false R3.htm 0000003 - Statement - Consolidated Statements of Assets and Liabilities Sheet http://fskkrcapitalcorp.com/role/ConsolidatedStatementsofAssetsandLiabilities Consolidated Statements of Assets and Liabilities Statements 3 false false R4.htm 0000004 - Statement - Consolidated Statements of Assets and Liabilities (Parenthetical) Sheet http://fskkrcapitalcorp.com/role/ConsolidatedStatementsofAssetsandLiabilitiesParenthetical Consolidated Statements of Assets and Liabilities (Parenthetical) Statements 4 false false R5.htm 0000005 - Statement - Consolidated Statements of Operations Sheet http://fskkrcapitalcorp.com/role/ConsolidatedStatementsofOperations Consolidated Statements of Operations Statements 5 false false R6.htm 0000006 - Statement - Consolidated Statements of Changes in Net Assets Sheet http://fskkrcapitalcorp.com/role/ConsolidatedStatementsofChangesinNetAssets Consolidated Statements of Changes in Net Assets Statements 6 false false R7.htm 0000007 - Statement - Consolidated Statements of Cash Flows Sheet http://fskkrcapitalcorp.com/role/ConsolidatedStatementsofCashFlows Consolidated Statements of Cash Flows Statements 7 false false R8.htm 0000008 - Statement - Consolidated Schedule of Investments Sheet http://fskkrcapitalcorp.com/role/ConsolidatedScheduleofInvestments Consolidated Schedule of Investments Statements 8 false false R9.htm 0000009 - Statement - Consolidated Schedule of Investments (Parenthetical) Sheet http://fskkrcapitalcorp.com/role/ConsolidatedScheduleofInvestmentsParenthetical Consolidated Schedule of Investments (Parenthetical) Statements 9 false false R10.htm 0000010 - Disclosure - Principal Business and Organization Sheet http://fskkrcapitalcorp.com/role/PrincipalBusinessandOrganization Principal Business and Organization Notes 10 false false R11.htm 0000011 - Disclosure - Summary of Significant Accounting Policies Sheet http://fskkrcapitalcorp.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 11 false false R12.htm 0000012 - Disclosure - Share Transactions Sheet http://fskkrcapitalcorp.com/role/ShareTransactions Share Transactions Notes 12 false false R13.htm 0000013 - Disclosure - Related Party Transactions Sheet http://fskkrcapitalcorp.com/role/RelatedPartyTransactions Related Party Transactions Notes 13 false false R14.htm 0000014 - Disclosure - Distributions Sheet http://fskkrcapitalcorp.com/role/Distributions Distributions Notes 14 false false R15.htm 0000015 - Disclosure - Investment Portfolio Sheet http://fskkrcapitalcorp.com/role/InvestmentPortfolio Investment Portfolio Notes 15 false false R16.htm 0000016 - Disclosure - Fair Value of Financial Instruments Sheet http://fskkrcapitalcorp.com/role/FairValueofFinancialInstruments Fair Value of Financial Instruments Notes 16 false false R17.htm 0000017 - Disclosure - Financing Arrangements Sheet http://fskkrcapitalcorp.com/role/FinancingArrangements Financing Arrangements Notes 17 false false R18.htm 0000018 - Disclosure - Commitments and Contingencies Sheet http://fskkrcapitalcorp.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 18 false false R19.htm 0000019 - Disclosure - Financial Highlights Sheet http://fskkrcapitalcorp.com/role/FinancialHighlights Financial Highlights Notes 19 false false R20.htm 0000020 - Disclosure - Subsequent Events Sheet http://fskkrcapitalcorp.com/role/SubsequentEvents Subsequent Events Notes 20 false false R21.htm 0000021 - Disclosure - Selected Quarterly Financial Data (Unaudited) Sheet http://fskkrcapitalcorp.com/role/SelectedQuarterlyFinancialDataUnaudited Selected Quarterly Financial Data (Unaudited) Notes 21 false false R22.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 22 false false R23.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 23 false false R24.htm 995470 - Disclosure - N-2 Sheet http://xbrl.sec.gov/cef/role/N2 N-2 Notes 24 false false R25.htm 9954701 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://fskkrcapitalcorp.com/role/SummaryofSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://fskkrcapitalcorp.com/role/SummaryofSignificantAccountingPolicies 25 false false R26.htm 9954702 - Disclosure - Share Transactions (Tables) Sheet http://fskkrcapitalcorp.com/role/ShareTransactionsTables Share Transactions (Tables) Tables http://fskkrcapitalcorp.com/role/ShareTransactions 26 false false R27.htm 9954703 - Disclosure - Related Party Transactions (Tables) Sheet http://fskkrcapitalcorp.com/role/RelatedPartyTransactionsTables Related Party Transactions (Tables) Tables http://fskkrcapitalcorp.com/role/RelatedPartyTransactions 27 false false R28.htm 9954704 - Disclosure - Distributions (Tables) Sheet http://fskkrcapitalcorp.com/role/DistributionsTables Distributions (Tables) Tables http://fskkrcapitalcorp.com/role/Distributions 28 false false R29.htm 9954705 - Disclosure - Investment Portfolio (Tables) Sheet http://fskkrcapitalcorp.com/role/InvestmentPortfolioTables Investment Portfolio (Tables) Tables http://fskkrcapitalcorp.com/role/InvestmentPortfolio 29 false false R30.htm 9954706 - Disclosure - Fair Value of Financial Instruments (Tables) Sheet http://fskkrcapitalcorp.com/role/FairValueofFinancialInstrumentsTables Fair Value of Financial Instruments (Tables) Tables http://fskkrcapitalcorp.com/role/FairValueofFinancialInstruments 30 false false R31.htm 9954707 - Disclosure - Financing Arrangements (Tables) Sheet http://fskkrcapitalcorp.com/role/FinancingArrangementsTables Financing Arrangements (Tables) Tables http://fskkrcapitalcorp.com/role/FinancingArrangements 31 false false R32.htm 9954708 - Disclosure - Commitments and Contingencies (Tables) Sheet http://fskkrcapitalcorp.com/role/CommitmentsandContingenciesTables Commitments and Contingencies (Tables) Tables http://fskkrcapitalcorp.com/role/CommitmentsandContingencies 32 false false R33.htm 9954709 - Disclosure - Financial Highlights (Tables) Sheet http://fskkrcapitalcorp.com/role/FinancialHighlightsTables Financial Highlights (Tables) Tables http://fskkrcapitalcorp.com/role/FinancialHighlights 33 false false R34.htm 9954710 - Disclosure - Selected Quarterly Financial Data (Unaudited) (Tables) Sheet http://fskkrcapitalcorp.com/role/SelectedQuarterlyFinancialDataUnauditedTables Selected Quarterly Financial Data (Unaudited) (Tables) Tables http://fskkrcapitalcorp.com/role/SelectedQuarterlyFinancialDataUnaudited 34 false false R35.htm 9954711 - Disclosure - Summary of Significant Accounting Policies (Details) Sheet http://fskkrcapitalcorp.com/role/SummaryofSignificantAccountingPoliciesDetails Summary of Significant Accounting Policies (Details) Details http://fskkrcapitalcorp.com/role/SummaryofSignificantAccountingPoliciesPolicies 35 false false R36.htm 9954712 - Disclosure - Share Transactions - Schedule of Common Stock Transactions (Details) Sheet http://fskkrcapitalcorp.com/role/ShareTransactionsScheduleofCommonStockTransactionsDetails Share Transactions - Schedule of Common Stock Transactions (Details) Details 36 false false R37.htm 9954713 - Disclosure - Share Transactions - Narrative (Details) Sheet http://fskkrcapitalcorp.com/role/ShareTransactionsNarrativeDetails Share Transactions - Narrative (Details) Details 37 false false R38.htm 9954714 - Disclosure - Related Party Transactions - Narrative (Details) Sheet http://fskkrcapitalcorp.com/role/RelatedPartyTransactionsNarrativeDetails Related Party Transactions - Narrative (Details) Details 38 false false R39.htm 9954715 - Disclosure - Related Party Transactions - Fees And Expenses Accrued (Details) Sheet http://fskkrcapitalcorp.com/role/RelatedPartyTransactionsFeesAndExpensesAccruedDetails Related Party Transactions - Fees And Expenses Accrued (Details) Details 39 false false R40.htm 9954716 - Disclosure - Related Party Transactions - Expense Support Agreement and Expiration for Future Possible Reimbursements (Details) Sheet http://fskkrcapitalcorp.com/role/RelatedPartyTransactionsExpenseSupportAgreementandExpirationforFuturePossibleReimbursementsDetails Related Party Transactions - Expense Support Agreement and Expiration for Future Possible Reimbursements (Details) Details 40 false false R41.htm 9954717 - Disclosure - Distributions - Cash Distributions (Details) Sheet http://fskkrcapitalcorp.com/role/DistributionsCashDistributionsDetails Distributions - Cash Distributions (Details) Details 41 false false R42.htm 9954718 - Disclosure - Distributions - Narrative (Details) Sheet http://fskkrcapitalcorp.com/role/DistributionsNarrativeDetails Distributions - Narrative (Details) Details 42 false false R43.htm 9954719 - Disclosure - Distributions - Cash Distributions on Common Stock (Details) Sheet http://fskkrcapitalcorp.com/role/DistributionsCashDistributionsonCommonStockDetails Distributions - Cash Distributions on Common Stock (Details) Details 43 false false R44.htm 9954720 - Disclosure - Distributions - Reconciliation Between GAAP-Basis Net Investment Income And Tax-basis Net Investment Income (Details) Sheet http://fskkrcapitalcorp.com/role/DistributionsReconciliationBetweenGAAPBasisNetInvestmentIncomeAndTaxbasisNetInvestmentIncomeDetails Distributions - Reconciliation Between GAAP-Basis Net Investment Income And Tax-basis Net Investment Income (Details) Details 44 false false R45.htm 9954721 - Disclosure - Distributions - Components Of Accumulated Earnings On A Tax Basis (Details) Sheet http://fskkrcapitalcorp.com/role/DistributionsComponentsOfAccumulatedEarningsOnATaxBasisDetails Distributions - Components Of Accumulated Earnings On A Tax Basis (Details) Details 45 false false R46.htm 9954722 - Disclosure - Investment Portfolio - Composition by Investment Type (Details) Sheet http://fskkrcapitalcorp.com/role/InvestmentPortfolioCompositionbyInvestmentTypeDetails Investment Portfolio - Composition by Investment Type (Details) Details 46 false false R47.htm 9954723 - Disclosure - Investment Portfolio - Narrative (Details) Sheet http://fskkrcapitalcorp.com/role/InvestmentPortfolioNarrativeDetails Investment Portfolio - Narrative (Details) Details 47 false false R48.htm 9954724 - Disclosure - Investment Portfolio - Composition by Industry Sector (Details) Sheet http://fskkrcapitalcorp.com/role/InvestmentPortfolioCompositionbyIndustrySectorDetails Investment Portfolio - Composition by Industry Sector (Details) Details 48 false false R49.htm 9954725 - Disclosure - Fair Value of Financial Instruments - Fair Value Hierarchy (Details) Sheet http://fskkrcapitalcorp.com/role/FairValueofFinancialInstrumentsFairValueHierarchyDetails Fair Value of Financial Instruments - Fair Value Hierarchy (Details) Details 49 false false R50.htm 9954726 - Disclosure - Fair Value of Financial Instruments - Roll Forward Level III (Details) Sheet http://fskkrcapitalcorp.com/role/FairValueofFinancialInstrumentsRollForwardLevelIIIDetails Fair Value of Financial Instruments - Roll Forward Level III (Details) Details 50 false false R51.htm 9954727 - Disclosure - Fair Value of Financial Instruments - Unobservable Inputs (Details) Sheet http://fskkrcapitalcorp.com/role/FairValueofFinancialInstrumentsUnobservableInputsDetails Fair Value of Financial Instruments - Unobservable Inputs (Details) Details 51 false false R52.htm 9954728 - Disclosure - Financing Arrangements - Narrative (Details) Sheet http://fskkrcapitalcorp.com/role/FinancingArrangementsNarrativeDetails Financing Arrangements - Narrative (Details) Details 52 false false R53.htm 9954729 - Disclosure - Financing Arrangements - Outstanding Financing Arrangements (Details) Sheet http://fskkrcapitalcorp.com/role/FinancingArrangementsOutstandingFinancingArrangementsDetails Financing Arrangements - Outstanding Financing Arrangements (Details) Details 53 false false R54.htm 9954730 - Disclosure - Financing Arrangements - Interest Expense (Details) Sheet http://fskkrcapitalcorp.com/role/FinancingArrangementsInterestExpenseDetails Financing Arrangements - Interest Expense (Details) Details 54 false false R55.htm 9954731 - Disclosure - Commitments and Contingencies - Narrative (Details) Sheet http://fskkrcapitalcorp.com/role/CommitmentsandContingenciesNarrativeDetails Commitments and Contingencies - Narrative (Details) Details 55 false false R56.htm 9954732 - Disclosure - Commitments and Contingencies - Unfunded Commitments (Details) Sheet http://fskkrcapitalcorp.com/role/CommitmentsandContingenciesUnfundedCommitmentsDetails Commitments and Contingencies - Unfunded Commitments (Details) Details 56 false false R57.htm 9954733 - Disclosure - Financial Highlights (Details) Sheet http://fskkrcapitalcorp.com/role/FinancialHighlightsDetails Financial Highlights (Details) Details http://fskkrcapitalcorp.com/role/FinancialHighlightsTables 57 false false R58.htm 9954734 - Disclosure - Subsequent Events (Details) Sheet http://fskkrcapitalcorp.com/role/SubsequentEventsDetails Subsequent Events (Details) Details http://fskkrcapitalcorp.com/role/SubsequentEvents 58 false false R59.htm 9954735 - Disclosure - Selected Quarterly Financial Data (Unaudited) (Details) Sheet http://fskkrcapitalcorp.com/role/SelectedQuarterlyFinancialDataUnauditedDetails Selected Quarterly Financial Data (Unaudited) (Details) Details http://fskkrcapitalcorp.com/role/SelectedQuarterlyFinancialDataUnauditedTables 59 false false All Reports Book All Reports kfit-20231231.htm kfit-20231231.xsd kfit-20231231_cal.xml kfit-20231231_def.xml kfit-20231231_lab.xml kfit-20231231_pre.xml kfit-20231231_g1.jpg kfit-20231231_g2.jpg http://fasb.org/us-gaap/2023 http://xbrl.sec.gov/cef/2023 http://xbrl.sec.gov/dei/2023 http://xbrl.sec.gov/ecd/2023 true true