Name:	siga_BasePeriodOfPerformanceExerciseOfOptions
Namespace Prefix:	siga_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The number of deliveries to be made during the base period of the government contract.

No definition available.

Name:	siga_GovernmentContractBasePeriodNumberOfDeliveries
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The value of the award for delivery and support activities under the government contract during the base period.

No definition available.

Name:	siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivities
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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.

No definition available.

Name:	siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesAdvancedDevelopment
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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.

No definition available.

Name:	siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesDeliveryOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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.

No definition available.

Name:	siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesManufactureOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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.

No definition available.

Name:	siga_GovernmentContractBasePeriodValueOfAwardForDeliveryAndSupportActivitiesSupportiveProcurementActivities
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Under a government contract, the number of courses to be manufactured upon exercise of options.

No definition available.

Name:	siga_GovernmentContractCoursesManufacturedUponExerciseOfOptions
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Under a government contract, the number of options that require the Company to manufacture product upon exercise.

No definition available.

Name:	siga_GovernmentContractNumberOfOptionsForManufactureOfProduct
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

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.

No definition available.

Name:	siga_GovernmentContractTotalAmountOfExercisedOptionsDeliveryOfMaterials
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Value of base contract award for a government contract.

No definition available.

Name:	siga_GovernmentContractValueOfAward
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of increase or decrease to the value of base contract award for a government contract.

No definition available.

Name:	siga_GovernmentContractValueOfAwardIncreaseDecrease
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The value of payments to be received related to unexercised options under the government contract to be used for supportive procurement activities.

No definition available.

Name:	siga_GovernmentContractValueOfUnexercisedOptionsSupportiveProcurementActivities
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of options exercised related to government contract value.

No definition available.

Name:	siga_GovernmentContractValueOptionExercisedValue
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the portion of the monetary value of a government contract related to payments currently specified as unexercised options.

No definition available.

Name:	siga_GovernmentContractValuePaymentsCurrentlySpecifiedAsUnexercisedOptions
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The value of payments to be received related to unexercised options under government contract to be used for the manufacture of courses.

No definition available.

Name:	siga_GovernmentContractValuePaymentsCurrentlySpecifiedAsUnexercisedOptionsManufactureOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The value of payments related to exercised options under the government contract to be used for the delivery of courses.

No definition available.

Name:	siga_GovernmentContractValuePaymentsRelatedToExercisedOptionsDeliveryOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The value of payments related to exercised options under the government contract to be used for funding of post-marketing activities.

No definition available.

Name:	siga_GovernmentContractValuePaymentsRelatedToExercisedOptionsFundingOfPostMarketingActivities
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the value of payments to be received from a government contract related to the exercise of options.

No definition available.

Name:	siga_GovernmentContractValuePaymentsRemainingRelatedToExercisedOptions
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents government contract value related to exercised options.

No definition available.

Name:	siga_GovernmentContractValueRelatedToExercisedOptions
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The number of courses delivered during the period.

No definition available.

Name:	siga_NumberOfCoursesDelivered
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of courses to be delivered.

No definition available.

Name:	siga_NumberOfCoursesToBeDelivered
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of steps in the manufacturing process of a product.

No definition available.

Name:	siga_NumberOfManufacturingSteps
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of vials in a course.

No definition available.

Name:	siga_NumberOfVialsInACourse
Namespace Prefix:	siga_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The cash inflow due to successful delivery of courses.

No definition available.

Name:	siga_ProceedsFromDeliveryOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The cash inflow during the period for activities classified as other during the base period of the contract.

No definition available.

Name:	siga_ProceedsFromOtherBasePeriodActivities
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The cash inflow from payments received for post-marketing activities.

No definition available.

Name:	siga_ProceedsFromPaymentsReceivedForPostmarketingActivities
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The cash inflow during the period from the delivery of courses.

No definition available.

Name:	siga_ProceedsFromTheDeliveryOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The cash inflow during the period from the manufacture of courses.

No definition available.

Name:	siga_ProceedsFromTheManufactureOfCourses
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479837/606-10-45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-8

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479837/606-10-45-2

Name:	us-gaap_ContractWithCustomerLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of revenue 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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-8

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=siga_The19CBARDAContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredOverTimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredAtPointInTimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ProductOrServiceAxis=siga_IVTPOXXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ProductOrServiceAxis=siga_IVBDSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ProductOrServiceAxis=siga_IVFDPContainingIvBdsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ProductOrServiceAxis=siga_OralTPOXXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ProductOrServiceAxis=siga_IVFDPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=siga_USDepartmentOfDefenseDoDMember
Namespace Prefix:
Data Type:	na
Balance Type:
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