3.24.3 html 1516 387 1 true 198 0 false 6 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://www.fdus.com/20240930/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - Consolidated Statements of Assets and Liabilities (unaudited) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedStatementsOfAssetsAndLiabilitiesUnaudited Consolidated Statements of Assets and Liabilities (unaudited) Statements 2 false false R3.htm 100020 - Statement - Consolidated Statements of Assets and Liabilities (Parenthetical) (unaudited) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedStatementsOfAssetsAndLiabilitiesParentheticalUnaudited Consolidated Statements of Assets and Liabilities (Parenthetical) (unaudited) Statements 3 false false R4.htm 100030 - Statement - Consolidated Statements of Operations (unaudited) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedStatementsOfOperationsUnaudited Consolidated Statements of Operations (unaudited) Statements 4 false false R5.htm 100040 - Statement - Consolidated Statements of Changes in Net Assets (unaudited) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedStatementsOfChangesInNetAssetsUnaudited Consolidated Statements of Changes in Net Assets (unaudited) Statements 5 false false R6.htm 100050 - Statement - Consolidated Statements of Cash Flows (unaudited) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsUnaudited Consolidated Statements of Cash Flows (unaudited) Statements 6 false false R7.htm 100060 - Statement - Consolidated Schedule of Investments (unaudited) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsUnaudited Consolidated Schedule of Investments (unaudited) Statements 7 false false R8.htm 100070 - Statement - Consolidated Schedule of Investments (unaudited) (Parenthetical) Sheet http://www.fdus.com/20240930/taxonomy/role/StatementConsolidatedScheduleOfInvestmentsUnauditedParenthetical Consolidated Schedule of Investments (unaudited) (Parenthetical) Statements 8 false false R9.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 9 false false R10.htm 995455 - Disclosure - Organization and Nature of Business Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureOrganizationAndNatureOfBusiness Organization and Nature of Business Notes 10 false false R11.htm 995465 - Disclosure - Significant Accounting Policies Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureSignificantAccountingPolicies1 Significant Accounting Policies Notes 11 false false R12.htm 995470 - Disclosure - N-2 Sheet http://xbrl.sec.gov/cef/role/N2 N-2 Notes 12 false false R13.htm 995475 - Disclosure - Portfolio Company Investments Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestments Portfolio Company Investments Notes 13 false false R14.htm 995485 - Disclosure - Fair Value Measurements Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurements1 Fair Value Measurements Notes 14 false false R15.htm 995495 - Disclosure - Related Party Transactions Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureRelatedPartyTransactions1 Related Party Transactions Notes 15 false false R16.htm 995505 - Disclosure - Debt Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebt3 Debt Notes 16 false false R17.htm 995515 - Disclosure - Commitments and Contingencies Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommitmentsAndContingencies1 Commitments and Contingencies Notes 17 false false R18.htm 995525 - Disclosure - Common Stock Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStock1 Common Stock Notes 18 false false R19.htm 995535 - Disclosure - Dividends and Distributions Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDividendsAndDistributions1 Dividends and Distributions Notes 19 false false R20.htm 995545 - Disclosure - Financial Highlights Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFinancialHighlights1 Financial Highlights Notes 20 false false R21.htm 995555 - Disclosure - Subsequent Events Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureSubsequentEvents Subsequent Events Notes 21 false false R22.htm 995565 - Disclosure - Significant Accounting Policies (Policies) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureSignificantAccountingPoliciesPolicies Significant Accounting Policies (Policies) Policies http://www.fdus.com/20240930/taxonomy/role/DisclosureSignificantAccountingPolicies1 22 false false R23.htm 995575 - Disclosure - Portfolio Company Investments (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsTables Portfolio Company Investments (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestments 23 false false R24.htm 995585 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurements1 24 false false R25.htm 995595 - Disclosure - Debt (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtTables Debt (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosureDebt3 25 false false R26.htm 995605 - Disclosure - Commitments and Contingencies (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommitmentsAndContingenciesTables Commitments and Contingencies (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosureCommitmentsAndContingencies1 26 false false R27.htm 995615 - Disclosure - Common Stock (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStockTables Common Stock (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStock1 27 false false R28.htm 995625 - Disclosure - Dividends and Distributions (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDividendsAndDistributionsTables Dividends and Distributions (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosureDividendsAndDistributions1 28 false false R29.htm 995635 - Disclosure - Financial Highlights (Tables) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFinancialHighlightsTables Financial Highlights (Tables) Tables http://www.fdus.com/20240930/taxonomy/role/DisclosureFinancialHighlights1 29 false false R30.htm 995645 - Disclosure - Organization and Nature of Business - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureOrganizationAndNatureOfBusinessAdditionalInformationDetails Organization and Nature of Business - Additional Information (Details) Details 30 false false R31.htm 995655 - Disclosure - Significant Accounting Policies - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureSignificantAccountingPoliciesAdditionalInformationDetails Significant Accounting Policies - Additional Information (Details) Details 31 false false R32.htm 995665 - Disclosure - Portfolio Company Investments - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsAdditionalInformationDetails Portfolio Company Investments - Additional Information (Details) Details 32 false false R33.htm 995675 - Disclosure - Portfolio Company Investments - Schedule of Investments Type With Corresponding Percentage of Total Portfolio Investments (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsScheduleOfInvestmentsTypeWithCorrespondingPercentageOfTotalPortfolioInvestmentsDetails Portfolio Company Investments - Schedule of Investments Type With Corresponding Percentage of Total Portfolio Investments (Details) Details 33 false false R34.htm 995685 - Disclosure - Portfolio Company Investments - Schedule of Investments Type With Corresponding Percentage of Total Portfolio Investments (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsScheduleOfInvestmentsTypeWithCorrespondingPercentageOfTotalPortfolioInvestmentsParentheticalDetails Portfolio Company Investments - Schedule of Investments Type With Corresponding Percentage of Total Portfolio Investments (Parenthetical) (Details) Details 34 false false R35.htm 995695 - Disclosure - Portfolio Company Investments - Schedule of Portfolio Composition by Geographic Region at Fair Value and Cost and as Percentage of Total Investments (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsScheduleOfPortfolioCompositionByGeographicRegionAtFairValueAndCostAndAsPercentageOfTotalInvestments Portfolio Company Investments - Schedule of Portfolio Composition by Geographic Region at Fair Value and Cost and as Percentage of Total Investments (Details) Details 35 false false R36.htm 995705 - Disclosure - Portfolio Company Investments - Schedule of Portfolio Composition by Type And by Geographic Region at Fair Value (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsScheduleOfPortfolioCompositionByTypeAndByGeographicRegionAtFairValueDetails Portfolio Company Investments - Schedule of Portfolio Composition by Type And by Geographic Region at Fair Value (Details) Details 36 false false R37.htm 995715 - Disclosure - Portfolio Company Investments - Schedule of Debt Investment on Non-Accrual Status (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsScheduleOfDebtInvestmentOnNonaccrualStatusDetails Portfolio Company Investments - Schedule of Debt Investment on Non-Accrual Status (Details) Details 37 false false R38.htm 995725 - Disclosure - Portfolio Company Investments - Schedule of Consolidated Schedule of Investments in and Advances to Affiliates (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosurePortfolioCompanyInvestmentsScheduleOfConsolidatedScheduleOfInvestmentsInAndAdvancesToAffiliatesDetails Portfolio Company Investments - Schedule of Consolidated Schedule of Investments in and Advances to Affiliates (Details) Details 38 false false R39.htm 995735 - Disclosure - Fair Value Measurements - Schedule of Fair Value Measuruments of Investments by Major Class According to Fair Value Hierachy (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfFairValueMeasurumentsOfInvestmentsByMajorClassAccordingToFairValueHierachyDetails Fair Value Measurements - Schedule of Fair Value Measuruments of Investments by Major Class According to Fair Value Hierachy (Details) Details 39 false false R40.htm 995745 - Disclosure - Fair Value Measurements - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetails Fair Value Measurements - Additional Information (Details) Details 40 false false R41.htm 995755 - Disclosure - Fair Value Measurements - Summary of Reconciliation of Beginning and Ending Balances for Fair Valued Investments (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfReconciliationOfBeginningAndEndingBalancesForFairValuedInvestmentsDetails Fair Value Measurements - Summary of Reconciliation of Beginning and Ending Balances for Fair Valued Investments (Details) Details 41 false false R42.htm 995765 - Disclosure - Fair Value Measurements - Summary of Significant Unobservable Inputs by Valuation Technique to Determine Fair Value (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfSignificantUnobservableInputsByValuationTechniqueToDetermineFairValueDetails Fair Value Measurements - Summary of Significant Unobservable Inputs by Valuation Technique to Determine Fair Value (Details) Details 42 false false R43.htm 995775 - Disclosure - Fair Value Measurements - Summary of Significant Unobservable Inputs by Valuation Technique to Determine Fair Value (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfSignificantUnobservableInputsByValuationTechniqueToDetermineFairValueParentheticalDetails Fair Value Measurements - Summary of Significant Unobservable Inputs by Valuation Technique to Determine Fair Value (Parenthetical) (Details) Details 43 false false R44.htm 995785 - Disclosure - Fair Value Measurements - Summary of Carrying Value and Fair Value of Debt Obligations (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfCarryingValueAndFairValueOfDebtObligationsDetails Fair Value Measurements - Summary of Carrying Value and Fair Value of Debt Obligations (Details) Details 44 false false R45.htm 995795 - Disclosure - Fair Value Measurements - Summary of Carrying Value and Fair Value of Debt Obligations (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfCarryingValueAndFairValueOfDebtObligationsParentheticalDetails Fair Value Measurements - Summary of Carrying Value and Fair Value of Debt Obligations (Parenthetical) (Details) Details 45 false false R46.htm 995805 - Disclosure - Fair Value Measurements - Summary of Inputs Used to Value Debt Obligations (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfInputsUsedToValueDebtObligationsDetails Fair Value Measurements - Summary of Inputs Used to Value Debt Obligations (Details) Details 46 false false R47.htm 995815 - Disclosure - Related Party Transactions - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails Related Party Transactions - Additional Information (Details) Details 47 false false R48.htm 995825 - Disclosure - Debt - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtAdditionalInformationDetails Debt - Additional Information (Details) Details 48 false false R49.htm 995835 - Disclosure - Debt - Summary of Issued and Outstanding SBA Debentures (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtSummaryOfIssuedAndOutstandingSbaDebenturesDetails Debt - Summary of Issued and Outstanding SBA Debentures (Details) Details 49 false false R50.htm 995855 - Disclosure - Debt - Summary of Interest and Fees Related to Debt (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtSummaryOfInterestAndFeesRelatedToDebtDetails Debt - Summary of Interest and Fees Related to Debt (Details) Details 50 false false R51.htm 995865 - Disclosure - Debt - Summary of Deferred Financing Costs Amortized into Interest and Financing Expenses (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtSummaryOfDeferredFinancingCostsAmortizedIntoInterestAndFinancingExpensesDetails Debt - Summary of Deferred Financing Costs Amortized into Interest and Financing Expenses (Details) Details 51 false false R52.htm 995875 - Disclosure - Debt - Summary of Outstanding Debt Net of Unamortized Deferred Financing Costs (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtSummaryOfOutstandingDebtNetOfUnamortizedDeferredFinancingCostsDetails Debt - Summary of Outstanding Debt Net of Unamortized Deferred Financing Costs (Details) Details 52 false false R53.htm 995885 - Disclosure - Debt - Summary of Outstanding Debt Net of Unamortized Deferred Financing Costs (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtSummaryOfOutstandingDebtNetOfUnamortizedDeferredFinancingCostsParentheticalDetails Debt - Summary of Outstanding Debt Net of Unamortized Deferred Financing Costs (Parenthetical) (Details) Details 53 false false R54.htm 995895 - Disclosure - Debt - Scheduled to Mature Debt Liabilities (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtScheduledToMatureDebtLiabilitiesDetails Debt - Scheduled to Mature Debt Liabilities (Details) Details 54 false false R55.htm 995905 - Disclosure - Debt - Scheduled to Mature Debt Liabilities (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDebtScheduledToMatureDebtLiabilitiesParentheticalDetails Debt - Scheduled to Mature Debt Liabilities (Parenthetical) (Details) Details 55 false false R56.htm 995915 - Disclosure - Commitments and Contingencies - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails Commitments and Contingencies - Additional Information (Details) Details 56 false false R57.htm 995925 - Disclosure - Commitments and Contingencies - Summary Of Outstanding Commitments (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommitmentsAndContingenciesSummaryOfOutstandingCommitmentsDetails Commitments and Contingencies - Summary Of Outstanding Commitments (Details) Details 57 false false R58.htm 995935 - Disclosure - Common Stock - Summary of Common Stock (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStockSummaryOfCommonStockDetails Common Stock - Summary of Common Stock (Details) Details 58 false false R59.htm 995945 - Disclosure - Common Stock - Summary of Common Stock (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStockSummaryOfCommonStockParentheticalDetails Common Stock - Summary of Common Stock (Parenthetical) (Details) Details 59 false false R60.htm 995955 - Disclosure - Common Stock - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStockAdditionalInformationDetails Common Stock - Additional Information (Details) Details 60 false false R61.htm 995965 - Disclosure - Common Stock - Summary of Equity ATM Program (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureCommonStockSummaryOfEquityAtmProgramDetails Common Stock - Summary of Equity ATM Program (Details) Details 61 false false R62.htm 995975 - Disclosure - Dividends and Distributions - Summary of Dividends Paid (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDividendsAndDistributionsSummaryOfDividendsPaidDetails Dividends and Distributions - Summary of Dividends Paid (Details) Details 62 false false R63.htm 995985 - Disclosure - Dividends and Distributions - Schedule of Purchased and Reissued Shares to Satisfy the DRIP Obligation (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureDividendsAndDistributionsScheduleOfPurchasedAndReissuedSharesToSatisfyTheDripObligationDetails Dividends and Distributions - Schedule of Purchased and Reissued Shares to Satisfy the DRIP Obligation (Details) Details 63 false false R64.htm 995995 - Disclosure - Financial Highlights - Schedule of Financial Highlights (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFinancialHighlightsScheduleOfFinancialHighlightsDetails Financial Highlights - Schedule of Financial Highlights (Details) Details 64 false false R65.htm 996005 - Disclosure - Financial Highlights - Schedule of Financial Highlights (Parenthetical) (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureFinancialHighlightsScheduleOfFinancialHighlightsParentheticalDetails Financial Highlights - Schedule of Financial Highlights (Parenthetical) (Details) Details 65 false false R66.htm 996015 - Disclosure - Subsequent Events - Additional Information (Details) Sheet http://www.fdus.com/20240930/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails Subsequent Events - Additional Information (Details) Details 66 false false All Reports Book All Reports fdus-20240930.htm fdus-20240930.xsd http://fasb.org/srt/2024 http://fasb.org/us-gaap/2024 http://xbrl.sec.gov/cef/2024 http://xbrl.sec.gov/dei/2024 http://xbrl.sec.gov/ecd/2024 false false