Note 10 - Related Party Transactions (Details Textual)		3 Months Ended
May 26, 2017 USD ($) ft²	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)
Director [Member]
Accounts Payable and Accrued Liabilities		$ 0
Consulting Agreement, Monthly Fee		20,000
Consulting Expense		60,000
MacAndrews and Forbes Incorporated [Member] \| The New HQ Lease [Member]
Area of Real Estate Property (Square Foot) \| ft²	3,200
Monthly Rent During Initial Period	$ 25,333
Monthly Rent, Initial Period (Month)	63 months
Monthly Rent After Initial Period	$ 29,333
Monthly Facility Fee, Second Year	$ 3,333
Monthly Facility Fee, Yearly Rate Increase After Second Year	5.00%
Monthly Facility Fee, Final Year	$ 4,925
Operating Lease, Expense		100,000	$ 100,000
Accounts Payable and Accrued Liabilities		$ 0

Represents monthly fee for consulting agreement.

No definition available.

Name:	siga_ConsultingAgreementMonthlyFee
Namespace Prefix:	siga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount of consulting expense during the period.

+ References

No definition available.

+ Details

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

- Definition

The amount of the monthly facility fee during the final year of the lease term.

+ References

No definition available.

+ Details

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

- Definition

The amount of the monthly facility fee during the second year of the lease term.

+ References

No definition available.

+ Details

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

- Definition

The percentage rate increase to the monthly facility fee per year following the second year of the lease term.

+ References

No definition available.

+ Details

Name:	siga_MonthlyFacilityFeeYearlyRateIncreaseAfterSecondYear
Namespace Prefix:	siga_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the monthly rental payments due under the rental agreement entered into after the initial period of the rental agreement.

+ References

No definition available.

+ Details

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

- Definition

The amount of the monthly rental payments due under the rental agreement entered into for the initial period of the rental agreement.

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

Sum of the carrying values as of the balance sheet date of obligations incurred through that date, including liabilities incurred and payable to vendors for goods and services received, taxes, interest, rent and utilities, compensation costs, payroll taxes and fringe benefits (other than pension and postretirement obligations), contractual rights and obligations, and statutory obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

+ Details

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

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of operating lease expense. Excludes sublease income.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479041/842-20-45-4

+ Details

Name:	us-gaap_OperatingLeaseExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	srt_TitleOfIndividualAxis=srt_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=siga_MacAndrewsAndForbesIncorporatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseContractualTermAxis=siga_TheNewHQLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: