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Concentration Risk, Credit Risk, Policy [Policy Text Block] Statement [Table] Directors’ fees payable Management Fee Payable Valuation Technique, Recent Transaction [Member] Measurement input valuation technique using recent transactions. Measurement Input, Equity Proceeds from Private Transaction [Member] Measurement input using equity proceeds from private transactions. srt_StockRepurchaseProgramAuthorizedAmount1 Stock Repurchase Program, Authorized Amount Ownership [Axis] us-gaap_IncreaseDecreaseInReceivableForInvestmentSold (Increase) decrease in receivable in investment sold Ownership [Domain] Consolidated Entities [Axis] Consolidated Entities [Domain] us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax Net Realized and Unrealized Gains (Losses) on Investments ASSETS Commitments and Contingencies Disclosure [Text Block] Statement [Line Items] Fair Value Hierarchy and NAV [Axis] Common stock, shares issued (in shares) Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Realized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax Net realized gain (loss) from security transactions and foreign currency Net realized gains (losses) Unrealized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax Net change in unrealized appreciation (depreciation) on investments Net change in unrealized appreciation (depreciation) Net unrealized (appreciation) depreciation from investments Total Shares of Common Stock outstanding (in shares) us-gaap_CommonStockSharesOutstanding Shares outstanding, beginning of period (in shares) Shares outstanding, end of period (in shares) Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Common stock, shares authorized (in shares) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Custody fees Those fees charged for services related to holding, advising, and managing customer investment assets. These account fees usually charged annually or semi-annually, on a per security basis, for the costs of services. us-gaap_CommonStockValue Common Stock, par value $0.001 per share 100,000,000 shares authorized Investment owned, cost yield Tax Period [Domain] Registration and filing fees Amount of registration fee expense for issuance of shares or units. Printing fees Amounts expended for printing of marketing and compliance communications and fulfillment services. 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Directors' fees may be paid in addition to salary and other benefits. Investment Company, Investment Owned, Measurement Input us-gaap_InvestmentCompanyInvestmentOwnedFairValueMeasurementInput Subsequent Event [Table] Deferred directors’ fees payable (Note 2) The amount of deferred director fees payable. Industry Sector [Domain] Fair Value Disclosures [Text Block] Substantial Doubt about Going Concern [Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] Accrued expenses and other payables Investments in and Advances to Affiliates, Schedule of Investments [Text Block] Treasury Stock [Text Block] Investment securities: Technology Sector [Member] Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name [Domain] Revenue Benchmark [Member] us-gaap_GainLossRelatedToLitigationSettlement Proceeds from Litigation Other Commitments [Table] Consulting fee payable Carrying value as of the balance sheet date of obligations incurred through that date and payable for consultation fees. Paid-in-capital Debt Disclosure [Text Block] svvc_NetAssets NET ASSETS Amount of net assets (liabilities). Use of Estimates, Policy [Policy Text Block] Fair Value, Recurring and Nonrecurring [Table] Industry Sector [Axis] Compliance fees Information pertaining to the amount of compliance fee expense. 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Share Valuation [Policy Text Block] Disclosure of accounting policy for the valuation of shares. EXPENSES Securities Transactions [Policy Text Block] Disclosure of accounting policy for security transactions. us-gaap_NetInvestmentIncome Net Investment Income NET INVESTMENT INCOME/(LOSS) Restricted Investments [Policy Text Block] Disclosure of accounting policy for restricted investments. Measurement Input Type [Domain] Measurement Input, Revenue Multiple [Member] Interest Interest Restricted Securities [Member] Represents investments in restricted securities. Measurement Input, Risk Free Interest Rate [Member] Capital loss carryforward Tax expense(2)(3) (in dollars per share) Per share or unit amount of deferred tax expense. Anti-dilutive effect from capital share transactions (in dollars per share) Per share or unit amount of the anti-dilutive effect from capital share transactions. State Valuation Technique, Option Pricing Model [Member] us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Unusual or Infrequent Items, or Both, Disclosure [Text Block] us-gaap_DeferredTaxAssetsGross Total deferred tax assets, net Income Tax Disclosure [Text Block] Unusual or Infrequent Item, or Both [Table] Total expenses, excluding incentive fees and deferred tax expense Percentage, net of incentive fee and deferred tax expense (benefit), of expense to average net assets. Net operating loss carryforward svvc_InvestmentCompanyExpenseRatioNetOfDeferredTaxExpenseBenefit Total expenses Percentage, after deferred tax expense (benefit), of expense to average net assets. Accounting Standards Update and Change in Accounting Principle [Table] us-gaap_DeferredTaxAssetsNet Net svvc_InvestmentCompanyExpenseRatioBeforeDeferredTaxExpenseBenefit Before tax (benefit)/expense Percentage, before deferred tax expense (benefit), of expense to average net assets. Unusual Risk or Uncertainty [Table] Income Tax, Policy [Policy Text Block] Miscellaneous fees Related and Nonrelated Parties [Domain] Related Party Transaction [Table] Related Party Transactions Disclosure [Text Block] Valuation Technique, Liquidation Value [Member] Valuation technique using the liquidation value. Measurement Input, Going Concern Probability [Member] Measurement input using going concern probability. Deferred Tax Asset [Domain] Net investment income (loss)(1) (in dollars per share) Per share or unit amount, after investment expense, of dividend and interest investment income (loss) before deferred income taxes. Fair Value Hierarchy and NAV [Domain] Valuation Allowance by Deferred Tax Asset [Axis] Venture Capital Funds [Member] Statement of Financial Position [Abstract] us-gaap_DeferredTaxAssetsValuationAllowance Valuation allowance Deferred Tax Asset, Valuation Allowance [Table] Carryforward, Expiration Date 4 [Member] Pertains to the expiration date of the carryforward. Realized gains (losses) Class of Treasury Stock [Table] Investment advisory fees (Note 4) Total percentage of net asset value The percentage of net assets of net assets. Other assets Mutual Fund [Member] Directors' fees svvc_DeferredCompensationArrangementPercentOfCompensationDeferred Deferred Compensation Arrangement, Percent of Compensation Deferred Amount of compensation deferred under deferred compensation arrangement as percentage. Transfer agent fees Measurement input, Market Value of Invested Capital [Member] Measurement input using the market Value of invested capital. svvc_InvestmentCompanyFeeWaivedOrReimbursed Net legal fees reimbursement Amount of fee waived or reimbursed by investment company. us-gaap_IncreaseDecreaseInOtherOperatingAssets (Increase) decrease in other assets Net asset value per share (Note 2) (in dollars per share) Net Asset Value Per Share (in dollars per share) Net asset value at beginning of period (in dollars per share) Net asset value at end of period (in dollars per share) Document Type Document Information [Line Items] Document Quarterly Report us-gaap_ConcentrationRiskPercentage1 Concentration Risk, Percentage Document Information [Table] Entity Interactive Data Current Document Transition Report Net Increase (Decrease) In Net Assets Per Share Resulting From Operations (1) (in dollars per share) svvc_InvestmentCompanyExpenseIncomeAfterReductionOfFeeWaiverAndReimbursement TOTAL NET EXPENSES Amount, after reimbursement and fee waiver, of expense for generation of investment income classified as operating. Document Fiscal Period Focus Document Fiscal Year Focus Amendment Flag Unrealized appreciation (depreciation) Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Common Stock [Member] Maturity date Document Period End Date Investment [Table Text Block] Legal Entity [Axis] Entity File Number Entity Tax Identification Number Total Affiliates and Controlled Investments Amount, after tax, of unrealized gain (loss) on investment, derivative, and foreign currency transaction, classified as operating. Investment includes, but is not limited to, debt and equity securities, security sold short, real estate, and commodity. Entity [Domain] Entity Central Index Key Entity Registrant Name Entity Current Reporting Status Entity Incorporation, State or Country Code Current Fiscal Year End Date Entity Ex Transition Period Entity Filer Category Entity Shell Company Entity Emerging Growth Company Entity Small Business Investments [Domain] Valuation Approach and Technique [Axis] Capital loss carryforwards Operating Loss Carryforwards Securities, realized gain (loss) svvc_NumberOfSubsidiaries Number of Subsidiaries The number of subsidiaries. Valuation Approach and Technique [Domain] Valuation, Market Approach [Member] Entity Address, State or Province Entity Address, City or Town Total distributable earnings (loss) Entity Address, Address Line One Small-cap Stocks Companies [Member] Companies with market capitalizations less than $250 million. Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Technology Companies [Member] Information by name of entity in which ownership interest is disclosed. Excludes equity method investee and named security investment. City Area Code Local Phone Number Entity Address, Postal Zip Code Cayman Subsidiaries [Member] Represent Cayman subsidiaries. Preferred Stock [Member] Unusual Risks and Uncertainties Disclosure [Text Block] The entire disclosure of the nature of the unusual risk or uncertainty, if estimable, such as the threat of expropriation of its assets by a foreign government, rapid technological obsolescence in the industry, risk of natural disaster from earthquake or weather events, and availability of or continuation of a labor force at a reasonable cost. Title of 12(b) Security Trading Symbol Derivatives, Policy [Policy Text Block] Class of Stock [Axis] Subsidiaries [Member] Revenue [Policy Text Block] Affiliated/controlled investments and foreign currency Amount, before tax, of unrealized gain (loss) from debt, equity securities and foreign currency transactions. Entity Common Stock, Shares Outstanding Management [Member] us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales Sales Accrued taxes Purchases us-gaap_FairValueAssetRecurringBasisStillHeldUnrealizedGainLossStatementOfIncomeExtensibleList Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Common stock, par value (in dollars per share) Basis of Accounting, Policy [Policy Text Block] Medical Devices Sector [Member] Sector of economy consisting of companies engaged in business activity related to medical devices. Advanced Materials Sector [Member] Sector of economy consisting of companies engaged in business activity related to advanced materials. Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Net investment income (loss) before fee waiver Percentage of investment income (loss) to average net assets before deduction of fee waiver. us-gaap_Assets Total Assets Cash and Cash Equivalents, Policy [Policy Text Block] Investments, market value, total Investments, fair value Investment Owned, Fair Value Investments, fair value Investments, fair value Total expenses, excluding incentive fees and deferred tax expense and fee waiver Percentage, after deduction of fee waiver, incentive fee, and deferred tax expense (benefit), of expense to average net assets. svvc_IncreaseDecreaseInInterestDividendsAndReclaimsReceivable (Increase) decrease in dividends, interest, and reclaims receivable The increase (decrease) during the reporting period in the aggregate amount due to the entity in the form of unpaid interest, dividends. and reclaims. Investments in and Advances to Affiliates [Table Text Block] Investments in and Advances to Affiliates [Table] svvc_PolicyTable Investment Holdings [Text Block] Investment [Text Block] Investment, shares/par value (in shares) Investment, shares/par value (in shares) us-gaap_TaxBasisOfInvestmentsUnrealizedAppreciationDepreciationNet Net unrealized depreciation NET ASSETS: Investment Company, Change in Net Assets [Abstract] Investment Company, Financial Highlights [Text Block] Investment Holdings [Table] Investment Company, Financial Highlights [Table Text Block] us-gaap_ProceedsFromSaleOfSecuritiesOperatingActivities Proceeds from sales and maturities of investment securities us-gaap_InvestmentCompanyDistributionToShareholdersPerShare Realized capital gains (in dollars per share) Semiconductor Equipment Sector [Member] Sector of economy consisting of companies engaged in business activity related to semi-conductor equipment. Investment Type [Axis] NET ASSETS — 100.0% Net assets at end of period (millions) Net Assets NET ASSETS Beginning of period End of period us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare Total from investment operations (in dollars per share) Net realized and unrealized gains (losses) on investments (in dollars per share) Investment Company, Financial Highlights [Table] Investment, cost Investment, cost Based on Net Asset Value Disposal Group Name [Domain] Asset Less Noninvestment Liability, Percent of Net Asset Total Return Net investment income (loss) Federal income tax cost, Investments OTHER LIABILITIES IN EXCESS OF OTHER ASSETS — 133.3% svvc_OperatingLossCarryforwardsPeriod Operating Loss Carryforwards, Period (Year) Pertains to operating loss carryforward period. INVESTMENT INCOME Difference in Tax Rate Due to changes in Deferred Tax Assets [Member] Pertains to the deferred tax asset for which a valuation reserve exists. Federal Income Tax Note [Table] Disposal Group Name [Axis] us-gaap_TaxBasisOfInvestmentsGrossUnrealizedDepreciation Gross unrealized depreciation COMMON STOCK ACTIVITY: Gross unrealized appreciation Carryforward, Expiration Date 3 [Member] Pertains to the expiration date of the carryforward. Carryforward, Expiration Date 2 [Member] Pertains to the expiration date of the carryforward. Investment, Affiliated Issuer, Controlled [Member] Investment, Unaffiliated Issuer [Member] Investment, Affiliated Issuer [Member] Investment, Issuer Affiliation [Axis] Carryforward, Expiration Date 1 [Member] Pertains to the expiration date of the carryforward. Investment, Issuer Affiliation [Domain] Investment Company, Modified Dutch Auction Tender Offer [Member] Pertains to the type of buyback. Investment Company, Share Repurchase Plan [Member] Pertains to the type of buyback. Acquisition date Acquisition date Investment Company, Tender Offer [Member] Pertains to the type of buyback. Concentration Risk Benchmark [Axis] us-gaap_RepurchaseAgreementDateOfRepurchase Repurchase Agreement, Date of Repurchase us-gaap_InvestmentsInAndAdvancesToAffiliatesAtFairValueGrossReductions Sales/maturity/expiration Concentration Risk Benchmark [Domain] Federal Income Tax Note [Table Text Block] us-gaap_RepurchaseAgreementDate Repurchase Agreement, Date Purchase/merger Consolidation, Less-than-Wholly-Owned Subsidiary, Parent Ownership Interest, Effect of Change [Table] svvc_DeferredCompensationArrangementNetAssetValueToTriggerNotationalCashContingency Deferred Compensation Arrangement, Net Asset Value to Trigger Notational Cash Contingency (in dollars per share) The net asset value amount that triggers the notational cash contingency in a deferred compensation arrangement. ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] svvc_StockRepurchasePurchasePriceOfCommonStockPercent Stock Repurchase, Purchase Price of Common Stock, Percent Purchase price of common stock expressed as a percentage of Net Value Added (NAV) per share. Investment, Controlled [Member] Represents controlled investment. Summary Investment Holdings [Table Text Block] Income from investment operations: