Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2012	Feb. 15, 2013	Jun. 30, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	SIGA TECHNOLOGIES INC
Entity Central Index Key	0001010086
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Trading Symbol	SIGA
Document Type	10-K
Document Period End Date	Dec. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Amendment Flag	true
Amendment Description	This Amendment No. 1 on Form 10-K/A (Amendment No. 1) amends the Annual Report on Form 10-K of SIGA Technologies, Inc. (the Company) for the year ended December 31, 2012, as originally filed with the Securities and Exchange Commission (SEC) on March 6, 2012 (Original Filing).. The Company is filing this Amended Annual Report on Form 10-K/A (the “Amended Filing” or “Form 10-K/A”) to our Annual Report on Form 10-K for the year ended December 31, 2012 (the “Original Filing”) to amend and restate our audited consolidated financial statements and related disclosures as of and for the years ended December 31, 2011 and 2010 included in Item 8, Note 3, “Revision and Restatement of Consolidated Financial Statements”, as well as selected quarterly financial data (excluding footnotes) for the periods from March 31, 2011 through December 31, 2011 included in Item 8, Note 15 - “Revised and Restated Financial Information By Quarter (Unaudited).”  The audited consolidated financial statements and related disclosures as of and for the year ended December 31, 2012 and the selected quarterly financial data for each of the quarters therein have also been revised to conform with the restated financial statements referred to herein; the conclusion to revise the amounts for 2012 resulted from the immaterial nature of the adjustments based on quantitative and qualitative considerations. The Original Filing was filed with the Securities and Exchange Commission (“SEC”) on March 6, 2013.
Entity Common Stock, Shares Outstanding		51,642,520
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 147,685,687