Organization and Basis of Presentation	12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure	Organization and Basis of Presentation Description of Business SIGA Technologies, Inc. (“SIGA” or the “Company”) is a commercial-stage pharmaceutical company focused on the health security market. Health security comprises countermeasures for biological, chemical, radiological and nuclear attacks (biodefense market), vaccines and therapies for emerging infectious diseases, and health preparedness. Our lead product is TPOXX®, an orally administered antiviral drug for the treatment of human smallpox disease caused by variola virus. In December of 2017, the Company submitted a New Drug Application (“NDA”) to the U.S Food and Drug Administration (“FDA”) for TPOXX®. In February 2018, the Company received notice that the FDA granted priority review of the NDA and that the FDA's target final action date is August 8, 2018. Liquidity The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern and contemplate the realization of assets and the satisfaction of liabilities in the normal course of business. The Company is not entitled to receive additional procurement-related payments under the current BARDA Contract (Note 3) if and until FDA approval of TPOXX® has been achieved, and there is no difference between the approved product and courses of TPOXX® that have been delivered to the U.S. Strategic National Stockpile (“Strategic Stockpile”). Upon meeting the aforementioned requirements, a determination of which is currently expected in the third quarter of 2018, the Company will be entitled to a $41 million hold back payment under the BARDA Contract. In the event that the Company does not receive a substantial portion of the hold back payment, or other substantial cash inflows, by October of 2018, then, based on currently forecasted operating costs, the Company will require additional sources of funding to continue operations and prevent an event of default under the term loan (Note 7). In this case, the Company would seek to increase cash liquidity by: raising proceeds through a financing, entering into a new contract for TPOXX® or any other product, a sale of assets, or the modification of the existing BARDA Contract; significantly reducing its operating expenses; or modifying the terms of the Term Loan Agreement. There can be no assurance that TPOXX® will receive FDA approval on a timely basis, if at all, or that there will be no difference between the approved product and courses of TPOXX® that have been delivered to the Strategic Stockpile. Furthermore, there can be no assurance that the Company would be able to increase cash liquidity, if needed, through a financing, a new contract for TPOXX® or any other product, a sale of assets, the modification of the existing BARDA Contract, or a significant reduction of its operating expenses or operations, or that the lenders would agree to modify the Term Loan Agreement, if needed. Because of these conditions, substantial doubt exists about the Company's ability to continue as a going concern for one year from the financial statement issuance date. Closing of Chapter 11 On April 12, 2016, the Company emerged from chapter 11 of the Bankruptcy Code when the Company's plan of reorganization (the “Plan”) became effective, and on December 22, 2016 the Company's chapter 11 case was closed by the Bankruptcy Court. Under the Plan, the Company fully paid all of its claims. The Company did not apply the provisions of fresh start accounting as ownership of existing shares of the Company's common stock remained unaltered by the Plan. Prior to April, 12 2016, the effective date of the Plan, the Company was operating its business as a “debtor-in-possession.” The Company had filed on September 16, 2014, a voluntary petition for relief under chapter 11 of Title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of New York (the “Bankruptcy Court”) chapter 11 Case Number 14-12623 (SHL). The chapter 11 case preserved the Company's ability to satisfy its commitments under the BARDA Contract (as defined in Note 3) and preserved its operations, which likely would have been jeopardized by the enforcement of a judgment stemming from the Company's litigation with PharmAthene, Inc. (“PharmAthene”) (see “PharmAthene Litigation” below). While operating as a debtor-in-possession under chapter 11, the Company pursued an appeal of the Delaware Court of Chancery Final Order and Judgment, without having to post a bond. PharmAthene Litigation On November 16, 2016, the Company satisfied the Judgment (as defined in Note 12) owed to PharmAthene in connection with the Company's litigation with PharmAthene. In total, PharmAthene was paid $217.0 million in connection with the Judgment. See Note 12 for additional details related to this litigation.

Organization and Basis of Presentation

Description of Business

SIGA Technologies, Inc. (“SIGA” or the “Company”) is a commercial-stage pharmaceutical company focused on the health security market. Health security comprises countermeasures for biological, chemical, radiological and nuclear attacks (biodefense market), vaccines and therapies for emerging infectious diseases, and health preparedness. Our lead product is TPOXX®, an orally administered antiviral drug for the treatment of human smallpox disease caused by variola virus.

In December of 2017, the Company submitted a New Drug Application (“NDA”) to the U.S Food and Drug Administration (“FDA”) for TPOXX®. In February 2018, the Company received notice that the FDA granted priority review of the NDA and that the FDA's target final action date is August 8, 2018.

Liquidity

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern and contemplate the realization of assets and the satisfaction of liabilities in the normal course of business. The Company is not entitled to receive additional procurement-related payments under the current BARDA Contract (Note 3) if and until FDA approval of TPOXX® has been achieved, and there is no difference between the approved product and courses of TPOXX® that have been delivered to the U.S. Strategic National Stockpile (“Strategic Stockpile”). Upon meeting the aforementioned requirements, a determination of which is currently expected in the third quarter of 2018, the Company will be entitled to a $41 million hold back payment under the BARDA Contract.

In the event that the Company does not receive a substantial portion of the hold back payment, or other substantial cash inflows, by October of 2018, then, based on currently forecasted operating costs, the Company will require additional sources of funding to continue operations and prevent an event of default under the term loan (Note 7). In this case, the Company would seek to increase cash liquidity by: raising proceeds through a financing, entering into a new contract for TPOXX® or any other product, a sale of assets, or the modification of the existing BARDA Contract; significantly reducing its operating expenses; or modifying the terms of the Term Loan Agreement. There can be no assurance that TPOXX® will receive FDA approval on a timely basis, if at all, or that there will be no difference between the approved product and courses of TPOXX® that have been delivered to the Strategic Stockpile. Furthermore, there can be no assurance that the Company would be able to increase cash liquidity, if needed, through a financing, a new contract for TPOXX® or any other product, a sale of assets, the modification of the existing BARDA Contract, or a significant reduction of its operating expenses or operations, or that the lenders would agree to modify the Term Loan Agreement, if needed. Because of these conditions, substantial doubt exists about the Company's ability to continue as a going concern for one year from the financial statement issuance date.

Closing of Chapter 11

On April 12, 2016, the Company emerged from chapter 11 of the Bankruptcy Code when the Company's plan of reorganization (the “Plan”) became effective, and on December 22, 2016 the Company's chapter 11 case was closed by the Bankruptcy Court. Under the Plan, the Company fully paid all of its claims. The Company did not apply the provisions of fresh start accounting as ownership of existing shares of the Company's common stock remained unaltered by the Plan.

Prior to April, 12 2016, the effective date of the Plan, the Company was operating its business as a “debtor-in-possession.” The Company had filed on September 16, 2014, a voluntary petition for relief under chapter 11 of Title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of New York (the “Bankruptcy Court”) chapter 11 Case Number 14-12623 (SHL). The chapter 11 case preserved the Company's ability to satisfy its commitments under the BARDA Contract (as defined in Note 3) and preserved its operations, which likely would have been jeopardized by the enforcement of a judgment stemming from the Company's litigation with PharmAthene, Inc. (“PharmAthene”) (see “PharmAthene Litigation” below). While operating as a debtor-in-possession under chapter 11, the Company pursued an appeal of the Delaware Court of Chancery Final Order and Judgment, without having to post a bond.

PharmAthene Litigation

On November 16, 2016, the Company satisfied the Judgment (as defined in Note 12) owed to PharmAthene in connection with the Company's litigation with PharmAthene. In total, PharmAthene was paid $217.0 million in connection with the Judgment. See Note 12 for additional details related to this litigation.