Document And Entity Information Statistical Measurement [Axis] Note To Financial Statement Details Textual us-gaap_DividendsPayableDateDeclaredDayMonthAndYear Dividends Payable, Date Declared Significant Accounting Policies us-gaap_IncomeTaxExpenseBenefit Income Tax Expense (Benefit) Provision for income taxes Note 4 - Inventory ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] Note 5 - Property, Plant and Equipment Transferred at Point in Time [Member] ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Note 6 - Accrued Expenses and Other Current Liabilities Issuance of common stock upon vesting of RSUs (in shares) Trading Arrangements, by Individual [Table] Note 8 - Per Share Data us-gaap_IncomeLossAttributableToParent Income (Loss) Attributable to Parent, before Tax Material Terms of Trading Arrangement [Text Block] Note 11 - Segment and Geographic Information Related and Nonrelated Parties [Axis] Note 13 - Equity Note 14 - Leases Note 4 - Inventory - Inventory (Details) Payment of common stock tendered for employee stock-based compensation tax obligations (in shares) Payment of common stock tendered for employee stock-based compensation tax obligations (in shares) Note 5 - Property, Plant and Equipment - Property, Plant and Equipment (Details) Note 6 - Accrued Expenses - Accrued Expenses and Other Current Liabilities (Details) Note 8 - Per Share Data - Reconciliation of the Basic and Diluted Loss Per Share (Details) Statistical Measurement [Domain] Note 11 - Segment and Geographic Information - Schedule of Operating Results (Details) Maximum [Member] Note 11 - Segment and Geographic Information - Revenues by Geographic Region (Details) Note 13 - Equity - Changes in Stockholders' Equity (Details) Note 13 - Equity - Changes in Stockholders' Equity (Details) (Parentheticals) Note 14 - Leases - Future Undiscounted Cash Flows Under Operating Leases (Details) us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable Notes To Financial Statements Notes To Financial Statements [Abstract] Accounts payable, accrued expenses and other liabilities Cash flows from operating activities: Cash flows from investing activities: us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities Raw materials Cash flows from financing activities: Work in-process us-gaap_NetCashProvidedByUsedInInvestingActivities Cash used in investing activities us-gaap_NetCashProvidedByUsedInFinancingActivities Cash used in financing activities Finished goods us-gaap_EffectiveIncomeTaxRateContinuingOperations Effective Income Tax Rate Reconciliation, Percent siga_ProceedsFromPaymentsReceivedForPostmarketingActivities Proceeds from Payments Received for Post-marketing Activities The cash inflow from payments received for post-marketing activities. us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent siga_GovernmentContractValuePaymentsRelatedToExercisedOptionsFundingOfPostMarketingActivities Government Contract, Value, Payments Related to Exercised Options, Funding of Post-Marketing Activities The value of payments related to exercised options under the government contract to be used for funding of post-marketing activities. Operating Segments [Member] Employee expenses Income Tax Jurisdiction [Domain] Accounting Policies [Abstract] Segments [Domain] us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable Income tax payable us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted Purchase Commitment, Remaining Minimum Amount Committed Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Table] us-gaap_CommonStockDividendsPerShareDeclared Common Stock, Dividends, Per Share, Declared (in dollars per share) Segments [Axis] siga_RevenuePerformanceObligationNumberOfObligations Revenue, Performance Obligation, Number of Obligations Represents the number of performance obligations. Leasehold Improvements [Member] us-gaap_IncreaseDecreaseInInventories Inventory Income Statement [Abstract] us-gaap_SharesOutstanding Balances (in shares) Balances (in shares) us-gaap_NumberOfOperatingSegments Number of Operating Segments siga_LesseeOperatingLeaseNumberOfRenewalOptions Lessee, Operating Lease, Number of Renewal Options Description of terms and conditions of option to renew lessee's operating lease. us-gaap_NumberOfReportableSegments Number of Reportable Segments siga_IncreaseDecreaseInOperatingRightofuseAssets Increase (Decrease) in Operating Right-of-use Assets Amount of increase (decrease) in assets for operating lease. Two Years, Option Renewal Term [Member] Information on transactions in connection with the exercise of the renewal option. Three Years, Option RenewalTerm [Member] Information on transactions in connection with the exercise of the renewal option. Deferred income taxes, net us-gaap_DeferredIncomeTaxExpenseBenefit siga_GovernmentContractValuePaymentsRelatedToExercisedOptionsDeliveryOfCourses Government Contract, Value, Payments Related to Exercised Options, Delivery of Courses The value of payments related to exercised options under the government contract to be used for the delivery of courses. Dividends [Axis] Dividends [Domain] Segment Reporting [Table Text Block] Net income Net income for basic earnings per share Net and comprehensive income Adjustments to reconcile net income to net cash provided by operating activities: us-gaap_DividendsPayableDateOfRecordDayMonthAndYear Dividends Payable, Date of Record us-gaap_Liabilities Total liabilities siga_MonthlyRentAfterInitialPeriod Monthly Rent After Initial Period The amount of the monthly rental payments due under the rental agreement entered into after the initial period of the rental agreement. siga_MonthlyRentInitialPeriod Monthly Rent, Initial Period (Month) The length of time of the initial period of the rental agreement in which the fixed monthly payments and other agreements may be different from the remainder of the rental agreement. Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] siga_MonthlyRentDuringInitialPeriod Monthly Rent During Initial Period The amount of the monthly rental payments due under the rental agreement entered into for the initial period of the rental agreement. MacAndrews and Forbes Incorporated [Member] Related to MacAndrews & Forbes Incorporated ("M&F"). siga_MonthlyFacilityFeeFinalYear Monthly Facility Fee, Final Year The amount of the monthly facility fee during the final year of the lease term. us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity Consolidation Items [Axis] us-gaap_AreaOfRealEstateProperty Area of Real Estate Property (Square Foot) siga_MonthlyFacilityFeeYearlyRateIncreaseAfterSecondYear Monthly Facility Fee, Yearly Rate Increase After Second Year The percentage rate increase to the monthly facility fee per year following the second year of the lease term. siga_MonthlyFacilityFeeSecondYear Monthly Facility Fee, Second Year The amount of the monthly facility fee during the second year of the lease term. Segment Reporting [Table] us-gaap_IncreaseDecreaseInPrepaidExpense Prepaid expenses and other assets The New HQ Lease [Member] Related to the "New HQ Lease" agreement. us-gaap_ShareBasedCompensation Stock-based compensation Selling, general and administrative us-gaap_CostsAndExpenses Total operating expenses Consolidation Items [Domain] Income Tax Disclosure [Text Block] Lessee, Lease, Description [Table] us-gaap_PaymentsForCapitalImprovements Capital expenditures Lease Contractual Term [Axis] Lease Contractual Term [Domain] Changes in assets and liabilities: IV FDP [Member] Related to the drug product IV FDP. siga_GovernmentContractValuePaymentsCurrentlySpecifiedAsUnexercisedOptionsManufactureOfCourses Government Contract, Value, Payments Currently Specified as Unexercised Options, Manufacture of Courses The value of payments to be received related to unexercised options under government contract to be used for the manufacture of courses. Fair Value, by Balance Sheet Grouping [Table] Asia Pacific [Member] us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents Cash and cash equivalents at the beginning of period Cash and cash equivalents at end of period Related and Nonrelated Parties [Domain] us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect Net (decrease)/increase in cash and cash equivalents us-gaap_CashAndCashEquivalentsFairValueDisclosure Cash and Cash Equivalents, Fair Value Disclosure Cash dividend per share (in dollars per share) siga_GovernmentContractValueOfAwardIncreaseDecrease Government Contract, Value of Award, Increase (Decrease) Amount of increase or decrease to the value of base contract award for a government contract. Related Party Transaction [Table] Related Party Transactions Disclosure [Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Antidilutive Securities, Name [Domain] Statement [Table] us-gaap_OperatingLeasePayments Operating Lease, Payments Fair Value Hierarchy and NAV [Domain] siga_PolicyTable Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Statement of Financial Position [Abstract] us-gaap_DividendPayableDateToBePaidDayMonthAndYear Dividends Payable, Date to be Paid Other income, net Other income, net Write down/(recovery) of inventory, net The amount of gain (loss) on inventory write-down net of credits received. Product and Service [Domain] Product and Service [Axis] Professional service fee expenses siga_GovernmentContractCoursesManufacturedUponExerciseOfOptions Government Contract, Courses Manufactured Upon Exercise of Options Under a government contract, the number of courses to be manufactured upon exercise of options. Other assets siga_GovernmentContractNumberOfOptionsForManufactureOfProduct Government Contract, Number of Options for Manufacture of Product Under a government contract, the number of options that require the Company to manufacture product upon exercise. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total undiscounted cash flows under leases Oral TPOXX [Member] Related to the oral TPOXX product. siga_NumberOfManufacturingSteps Number of Manufacturing Steps The number of steps in the manufacturing process of a product. Deferred IV TPOXX® revenue us-gaap_IncreaseDecreaseInDeferredRevenue us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent Document Type us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent Accounts Payable and Accrued Liabilities Operating expenses Document Information [Line Items] Document Quarterly Report us-gaap_LesseeOperatingLeaseTermOfContract Lessee, Operating Lease, Term of Contract (Year) 2026 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths us-gaap_LesseeOperatingLeaseRenewalTerm Lessee, Operating Lease, Renewal Term (Year) us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1 Operating Lease, Weighted Average Remaining Lease Term (Year) Document Information [Table] us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1 Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year) us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) us-gaap_OperatingLeaseExpense Operating Lease, Expense Antidilutive Securities [Axis] us-gaap_IncrementalCommonSharesAttributableToContingentlyIssuableShares Effect of potential common shares (in shares) Entity Interactive Data Current Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Document Transition Report Commitments and Contingencies Disclosure [Text Block] 2027 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo Weighted average shares outstanding: diluted (in shares) Weighted-average shares: diluted (in shares) Statement [Line Items] Fair Value Hierarchy and NAV [Axis] Common stock, shares issued (in shares) Common stock, shares outstanding (in shares) Common stock, shares authorized (in shares) Weighted average shares outstanding: basic (in shares) Weighted-average shares (in shares) Schedule of Accrued Liabilities [Table Text Block] Basic income per share (in dollars per share) Income per share: basic (in dollars per share) Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table] Common stock ($.0001 par value, 600,000,000 shares authorized, 71,844,042 and 71,611,302, issued and outstanding at June 30, 2026 and December 31, 2025, respectively) Effective Income Tax Rate Reconciliation [Table] EMEA [Member] Schedule of Inventory, Current [Table Text Block] Schedule of Stockholders Equity [Table Text Block] Accounts payable Income Tax Jurisdiction [Axis] us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_TableTextBlock Notes Tables Compensation Computer Equipment [Member] Document Fiscal Period Focus Document Fiscal Year Focus us-gaap_AccountsPayableTradeCurrent Inventory Amendment Flag Common Stock [Member] Professional fees Goodwill Accrued expenses and other current liabilities Accrued expenses and other current liabilities Document Period End Date Property, Plant, and Equipment [Text Block] Long-Lived Asset, Class [Domain] Legal Entity [Axis] Significant Accounting Policies [Text Block] us-gaap_OperatingLeaseCost Operating Lease, Cost siga_GovernmentContractValueRelatedToExercisedOptions Government Contract Value Related To Exercised Options Represents government contract value related to exercised options. us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Less: Imputed interest Entity File Number us-gaap_RevenueRemainingPerformanceObligation Revenue, Remaining Performance Obligation, Amount Accrued dividends on unvested equity awards Represents the amount of accrued dividends on unvested equity awards. Entity Tax Identification Number Present value of lease liabilities Other us-gaap_OtherAccruedLiabilitiesCurrent Transferred over Time [Member] Lease liability, current portion Entity [Domain] Entity Central Index Key Entity Registrant Name Entity Current Reporting Status Entity Incorporation, State or Country Code Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Domain] Current Fiscal Year End Date Research and development Entity Filer Category Entity Shell Company Operating Lease Right of Use Assets [Member] Represents operating lease right of use assets. CANADA Entity Emerging Growth Company Entity Small Business us-gaap_OperatingIncomeLoss Operating income Income Tax Jurisdiction, Domestic Federal [Member] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Cash dividend ($0.60 per share) Cash dividend ($0.60) Amount of paid and unpaid common stock dividends declared with the form of settlement in cash. us-gaap_ContractWithCustomerLiabilityRevenueRecognized Contract with Customer, Liability, Revenue Recognized us-gaap_SegmentReportingOtherItemAmount Other segment items us-gaap_Revenues Revenue Entity Address, State or Province Entity Address, City or Town Inventory, Current [Table] Accumulated deficit Entity Address, Address Line One Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Statement of Cash Flows [Abstract] City Area Code us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation Payment of employee tax obligations for common stock tendered Local Phone Number Statutory Accounting Practices [Table] Entity Address, Postal Zip Code Revenue from Contract with Customer [Text Block] siga_NumberOfVialsInACourse Number of Vials in a Course The number of vials in a course. Stockholders’ equity Title of 12(b) Security Equity Components [Axis] Security Exchange Name Trading Symbol siga_ContractWithCustomerLiabilityRevenueRecognizedIncludingBeginningBalance Contract With Customer Liability, Revenue Recognized Including Beginning Balance Amount of revenue including beginning balance recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Class of Stock [Axis] Equity Component [Domain] siga_GovernmentContractTotalAmountOfExercisedOptionsDeliveryOfMaterials Government Contract, Total Amount of Exercised Options, Delivery of Materials The value of the total amount of exercised options in a period for the delivery of courses to the Strategic Stockpile under the government contract. Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 1 [Member] Equity [Text Block] AOCI Attributable to Parent [Member] Entity Common Stock, Shares Outstanding Additional Paid-in Capital [Member] Retained Earnings [Member] Earnings Per Share [Text Block] Cost of sales and supportive services us-gaap_InventoryWriteDown Inventory Write-down Property, plant and equipment, net Property, plant and equipment, net Property, plant and equipment, gross Purchase of manufacturing equipment Research and Development [Member] Revenue generating activities related to research and development. Product Sales and Supportive Services [Member] Article or substance produced by nature, labor or machinery and act of providing assistance. siga_AccruedManufacturingEquipmentCosts Manufacturing equipment Represents the amount of accrued manufacturing equipment costs at balance sheet date. Deferred tax asset, net Property, Plant, and Equipment [Policy Text Block] Facilities and Office Space in Corvallis Oregon [Member] Represents facilities and office space in corvallis oregon. Income tax payable Research and Development, Contract to Perform for Others [Table] siga_NumberOfCoursesToBeDelivered Number of Courses to Be Delivered The number of courses to be delivered. Procurement Contract and Research Agreements [Text Block] The entire disclosure for procurement contracts and research agreements including grants or contracts from various agencies of the U.S. government to support the reporting entity's research and development activities. Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Property, Plant, and Equipment [Table] Common stock, par value (in dollars per share) siga_GovernmentContractValueOfAward Government Contract, Value of Award Value of base contract award for a government contract. Furniture and Fixtures [Member] Stock-based compensation Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Deferred Compensation Arrangement with Individual, Excluding Share-Based Payment and Postretirement Benefit [Table] Long-Lived Asset, Class [Axis] us-gaap_Assets Total assets Cash and cash equivalents Geographical [Domain] Geographical [Axis] Fair Value Disclosures [Text Block] Supplemental disclosure of non-cash investing activities: Current liabilities us-gaap_LiabilitiesCurrent Total current liabilities Diluted income per share (in dollars per share) Income per share: diluted (in dollars per share) Revenue from Contract with Customer [Policy Text Block] Deferred IV TPOXX® revenue Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue [Table Text Block] Accounts receivable Depreciation and other amortization Depreciation, Depletion and Amortization us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation Payment of common stock tendered for employee stock-based compensation tax obligations International Procurement [Member] Information pertaining to the international procurement Contract. siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivities Government Contract, Base Period, Value of Award for Delivery and Support Activities The value of the award for delivery and support activities under the government contract during the base period. siga_GovernmentContractValuePaymentsCurrentlySpecifiedAsUnexercisedOptions Government Contract, Value, Payments Currently Specified as Unexercised Options Represents the portion of the monetary value of a government contract related to payments currently specified as unexercised options. siga_GovernmentContractValuePaymentsRemainingRelatedToExercisedOptions Government Contract, Value, Payments Remaining Related to Exercised Options Represents the value of payments to be received from a government contract related to the exercise of options. The 19C BARDA Contract [Member] Information pertaining to the 19C BARDA Contract. Inventory Disclosure [Text Block] Other Commitments [Table] us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less – accumulated depreciation and amortization siga_BasePeriodOfPerformanceExerciseOfOptions Base Period of Performance, Exercise of Options, Term (Year) The length of the base period of performance for a contract excluding extensions, and other modifications, in which options granted in the contract may be exercised. siga_ProceedsFromTheDeliveryOfCourses Proceeds from the Delivery of Courses The cash inflow during the period from the delivery of courses. S 2026 Q1 Dividends [Member] Represents special 2026 Q1 dividend. Manufacturing Equipment [Member] Represents the manufacturing equipment. Inventory Inventory Cash Settled and Performance Based RSU's [Member] Represents the cash settled and the performance based RSU's. us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Income before income taxes Research and development vendor costs Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to accrued research and development costs (due within one year or within the normal operating cycle if longer). Additional paid-in capital siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesDeliveryOfCourses Government Contract, Base Period, Value of Award for Delivery and Support Activities, Delivery of Courses The value of award for the delivery of courses portion of the government contract for delivery and support activities during the base period of the contract. us-gaap_StockholdersEquity Total stockholders’ equity Balances Balances siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesManufactureOfCourses Government Contract, Base Period, Value of Award for Delivery and Support Activities, Manufacture of Courses The value of award for the manufacture of courses portion of the government contract for delivery and support activities during the base period of the contract. siga_GovernmentContractBasePeriodNumberOfDeliveries Government Contract, Base Period, Number of Deliveries The number of deliveries to be made during the base period of the government contract. Prepaid expenses and other current assets siga_ProceedsFromDeliveryOfCourses Proceeds from Delivery of Courses The cash inflow due to successful delivery of courses. siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesSupportiveProcurementActivities Government Contract, Base Period, Value of Award for Delivery and Support Activities, Supportive Procurement Activities The value of award for the supportive procurement activities portion of the government contract for delivery and support activities during the base period of the contract. siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesAdvancedDevelopment Government Contract, Base Period, Value of Award for Delivery and Support Activities, Advanced Development The value of award for the advanced funding for new product portion of the government contract for delivery and support activities during the base period of the contract. IV BDS [Member] Related to the drug substance IV BDS, used in the manufacture of IV FDP. IV FDP Containing IV BDS [Member] IV FDP Containing IV BDS. us-gaap_PaymentsOfDividends Payment of dividend siga_ProceedsFromOtherBasePeriodActivities Proceeds from Other Base Period Activities The cash inflow during the period for activities classified as other during the base period of the contract. Lessee, Operating Leases [Text Block] siga_ProceedsFromTheManufactureOfCourses Proceeds from the Manufacture of Courses The cash inflow during the period from the manufacture of courses. Stock, Class of Stock [Table] UNITED STATES siga_NumberOfCoursesDelivered Number of Courses Delivered The number of courses delivered during the period. Non-US [Member] IV TPOXX [Member] Related to the final drug product IV TPOXX. Consolidation, Less-than-Wholly-Owned Subsidiary, Parent Ownership Interest, Effect of Change [Table] Current assets us-gaap_AssetsCurrent Total current assets Other liabilities Issuance of common stock upon vesting of RSUs ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] Property, Plant, and Equipment [Table Text Block] Total revenues ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] Single Reportable Segment [Member] Single Reportable Segment Commitments and contingencies