Related Party Transactions	12 Months Ended
Dec. 31, 2018
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transactions	Related Party Transactions GeneOne Life Sciences The Company owns 1,644,155 shares of common stock in GeneOne as of December 31, 2018; one of the Company's directors, Dr. David B. Weiner, acts as a consultant to GeneOne. In 2010, the Company entered into a collaboration and license agreement (the “GeneOne Agreement”) with GeneOne. Under the GeneOne Agreement, the Company granted GeneOne an exclusive license to the Company's SynCon^® universal influenza vaccine delivered with electroporation to be developed in certain countries in Asia (the “Product”). As consideration for the license granted to GeneOne, the Company received an upfront payment of $3.0 million, and is entitled to receive research support, annual license maintenance fees and royalties on net Product sales. The GeneOne Agreement also provides the Company with exclusive rights to supply devices for clinical and commercial purposes (including single use components) to GeneOne for use in the Product. The term of the GeneOne Agreement commenced upon execution and will extend on a country by country basis until the last to expire of all Royalty Periods for the territory (as such term is defined in the GeneOne Agreement) for any Product in that country, unless the GeneOne Agreement is terminated earlier in accordance with its provisions as a result of breach, by mutual agreement, or by GeneOne's right to terminate without cause upon prior written notice. In 2011, the Company entered into a collaborative development and license agreement (the “Hep Agreement”) with GeneOne. Under the Hep Agreement, as originally executed, the Company and GeneOne agreed to co-develop the Company’s SynCon^® therapeutic vaccines for hepatitis B and C infections (the “Hep Products”). Under the terms of the Hep Agreement, GeneOne will receive marketing rights for the Products in Asia, excluding Japan, and in return will fully fund IND-enabling and initial Phase 1 and 2 clinical studies with respect to the Hep Products. The Company will receive from GeneOne payments based on the achievement of clinical milestones and royalties based on sales of the Hep Products in the licensed territories, retaining all commercial rights to the Hep Products in all other territories. In 2013, the Company amended the Hep Agreement to grant back to the Company the SynCon^® therapeutic vaccines targeting hepatitis B, along with all associated rights, from the collaboration in return for certain remuneration including a percentage of license fees. In 2013, the Company further amended the Hep Agreement to in part provide exclusive patent rights to IL-28 technology for use with the Hep Products in Asia, excluding Japan. The Hep Agreement shall terminate upon the later of the expiration or abandonment of the last patent that is a component of the rights or 20 years after the effective date. In May 2015, the Company entered into a Collaborative Development Agreement with GeneOne to co-develop a DNA vaccine for MERS through Phase 1 clinical trials. Under the terms of the agreement, GeneOne will be responsible for funding all preclinical and clinical studies through Phase 1. In return, GeneOne will receive up to a 35% milestone-based ownership interest in the MERS immunotherapy upon achievement of the last milestone event of completion of the Phase 1 safety and immunogenicity study. The collaborative research program shall terminate upon the completion of activities under the development plan, unless sooner terminated. In January 2016, the Company and GeneOne amended the Collaborative Development Agreement for MERS to expand the agreement to test and advance the Company's DNA-based vaccine for preventing and treating Zika virus. GeneOne will be responsible for funding all preclinical and clinical studies through Phase 1. In return, GeneOne will receive up to a 35% milestone-based ownership interest in the Zika immunotherapy upon achievement of the last milestone event of the completion of the Phase 1 safety and immunogenicity study. All other agreement terms remain the same. In December 2017, the Company completed the sale of certain assets related to its compound VGX-1027 to GeneOne for a purchase price of $1.0 million. Revenue recognized from GeneOne consisted of licensing and other fees from the influenza and Zika collaborations. For the years ended December 31, 2018, 2017 and 2016, the Company recognized revenue from GeneOne of $342,000, $551,000 and $1.2 million, respectively. Operating expenses recorded from transactions with GeneOne relate primarily to biologics manufacturing and were $7.0 million, $2.3 million and $2.8 million for the years ended December 31, 2018, 2017 and 2016, respectively. At December 31, 2018 and 2017, the Company had an accounts payable and accrued liability balance of $372,000 and $107,000, respectively, related to GeneOne and its subsidiaries. At December 31, 2018 and 2017, $381,000 and $331,000, respectively, of prepayments made to GeneOne were classified as long-term other assets on the consolidated balance sheet. Plumbline Life Sciences, Inc. The Company owns 395,758 shares of common stock in PLS as of December 31, 2018; one of the Company's directors, Dr. David B Weiner, acts as a consultant to PLS. For the years ended December 31, 2018 and 2017, the Company recognized revenue from PLS of $107,000 and $215,000, respectively. At December 31, 2018 and 2017, the Company had an accounts receivable balance of $478,000 and $370,000, respectively, related to its license agreement with PLS. The Wistar Institute One of the Company's directors, Dr. David B. Weiner, is the Executive Vice President and Director of the Vaccine Center of The Wistar Institute ("Wistar"). In March 2016, the Company entered into collaborative research agreements with Wistar for preventive and therapeutic DNA-based immunotherapy applications and products developed by Dr. Weiner and Wistar for the treatment of cancers and infectious diseases. Under the terms of the agreement, the Company will reimburse Wistar for all direct and indirect costs incurred in the conduct of the collaborative research, not to exceed $3.1 million during the five-year term of the agreement. The Company will have the exclusive right to in-license new intellectual property developed in this agreement. In December 2016 the Company received a $6.1 million sub-grant through Wistar to develop a DNA-based monoclonal antibody against the Zika infection. The Company is also a collaborator with Wistar on an Integrated Preclinical/Clinical AIDS Vaccine Development grant from the NIAID, awarded in 2015. Deferred grant funding recognized from Wistar and recorded as contra-research and development expense, which was classified as grant revenue in the prior year, is related to work performed by the Company on the research sub-contract agreements. For the year ended December 31, 2018, the Company recorded $3.3 million as contra-research and development expense from Wistar. For the year ended December 31, 2017, the Company recognized revenue from Wistar of $2.6 million. Research and development expenses recorded from Wistar relate primarily to the collaborative research agreements and sub-contract agreements for the DARPA Ebola grant (see Note 4). Research and development expenses recorded from Wistar for the years ended December 31, 2018 and 2017 were $1.8 million and $2.3 million, respectively. At December 31, 2018 and 2017, the Company had an accounts receivable balance of $258,000 and $117,000, respectively, and an accounts payable and accrued liability balance of $554,000 and $820,000, respectively, related to Wistar.

Related Party Transactions

GeneOne Life Sciences

The Company owns 1,644,155 shares of common stock in GeneOne as of December 31, 2018; one of the Company's directors, Dr. David B. Weiner, acts as a consultant to GeneOne.

In 2010, the Company entered into a collaboration and license agreement (the “GeneOne Agreement”) with GeneOne. Under the GeneOne Agreement, the Company granted GeneOne an exclusive license to the Company's SynCon^® universal influenza vaccine delivered with electroporation to be developed in certain countries in Asia (the “Product”). As consideration for the license granted to GeneOne, the Company received an upfront payment of $3.0 million, and is entitled to receive research support, annual license maintenance fees and royalties on net Product sales. The GeneOne Agreement also provides the Company with exclusive rights to supply devices for clinical and commercial purposes (including single use components) to GeneOne for use in the Product. The term of the GeneOne Agreement commenced upon execution and will extend on a country by country basis until the last to expire of all Royalty Periods for the territory (as such term is defined in the GeneOne Agreement) for any Product in that country, unless the GeneOne Agreement is terminated earlier in accordance with its provisions as a result of breach, by mutual agreement, or by GeneOne's right to terminate without cause upon prior written notice.

In 2011, the Company entered into a collaborative development and license agreement (the “Hep Agreement”) with GeneOne. Under the Hep Agreement, as originally executed, the Company and GeneOne agreed to co-develop the Company’s SynCon^® therapeutic vaccines for hepatitis B and C infections (the “Hep Products”). Under the terms of the Hep Agreement, GeneOne will receive marketing rights for the Products in Asia, excluding Japan, and in return will fully fund IND-enabling and initial Phase 1 and 2 clinical studies with respect to the Hep Products. The Company will receive from GeneOne payments based on the achievement of clinical milestones and royalties based on sales of the Hep Products in the licensed territories, retaining all commercial rights to the Hep Products in all other territories. In 2013, the Company amended the Hep Agreement to grant back to the Company the SynCon^® therapeutic vaccines targeting hepatitis B, along with all associated rights, from the collaboration in return for certain remuneration including a percentage of license fees. In 2013, the Company further amended the Hep Agreement to in part provide exclusive patent rights to IL-28 technology for use with the Hep Products in Asia, excluding Japan. The Hep Agreement shall terminate upon the later of the expiration or abandonment of the last patent that is a component of the rights or 20 years after the effective date.

In May 2015, the Company entered into a Collaborative Development Agreement with GeneOne to co-develop a DNA vaccine for MERS through Phase 1 clinical trials. Under the terms of the agreement, GeneOne will be responsible for funding all preclinical and clinical studies through Phase 1. In return, GeneOne will receive up to a 35% milestone-based ownership interest in the MERS immunotherapy upon achievement of the last milestone event of completion of the Phase 1 safety and immunogenicity study. The collaborative research program shall terminate upon the completion of activities under the development plan, unless sooner terminated.

In January 2016, the Company and GeneOne amended the Collaborative Development Agreement for MERS to expand the agreement to test and advance the Company's DNA-based vaccine for preventing and treating Zika virus. GeneOne will be responsible for funding all preclinical and clinical studies through Phase 1. In return, GeneOne will receive up to a 35% milestone-based ownership interest in the Zika immunotherapy upon achievement of the last milestone event of the completion of the Phase 1 safety and immunogenicity study. All other agreement terms remain the same.

In December 2017, the Company completed the sale of certain assets related to its compound VGX-1027 to GeneOne for a purchase price of $1.0 million.

Revenue recognized from GeneOne consisted of licensing and other fees from the influenza and Zika collaborations. For the years ended December 31, 2018, 2017 and 2016, the Company recognized revenue from GeneOne of $342,000, $551,000 and $1.2 million, respectively.

Operating expenses recorded from transactions with GeneOne relate primarily to biologics manufacturing and were $7.0 million, $2.3 million and $2.8 million for the years ended December 31, 2018, 2017 and 2016, respectively.

At December 31, 2018 and 2017, the Company had an accounts payable and accrued liability balance of $372,000 and $107,000, respectively, related to GeneOne and its subsidiaries. At December 31, 2018 and 2017, $381,000 and $331,000, respectively, of prepayments made to GeneOne were classified as long-term other assets on the consolidated balance sheet.

Plumbline Life Sciences, Inc.

The Company owns 395,758 shares of common stock in PLS as of December 31, 2018; one of the Company's directors, Dr. David B Weiner, acts as a consultant to PLS.

For the years ended December 31, 2018 and 2017, the Company recognized revenue from PLS of $107,000 and $215,000, respectively. At December 31, 2018 and 2017, the Company had an accounts receivable balance of $478,000 and $370,000, respectively, related to its license agreement with PLS.

The Wistar Institute

One of the Company's directors, Dr. David B. Weiner, is the Executive Vice President and Director of the Vaccine Center of The Wistar Institute ("Wistar").

In March 2016, the Company entered into collaborative research agreements with Wistar for preventive and therapeutic DNA-based immunotherapy applications and products developed by Dr. Weiner and Wistar for the treatment of cancers and infectious diseases. Under the terms of the agreement, the Company will reimburse Wistar for all direct and indirect costs incurred in the conduct of the collaborative research, not to exceed $3.1 million during the five-year term of the agreement. The Company will have the exclusive right to in-license new intellectual property developed in this agreement.

In December 2016 the Company received a $6.1 million sub-grant through Wistar to develop a DNA-based monoclonal antibody against the Zika infection.

The Company is also a collaborator with Wistar on an Integrated Preclinical/Clinical AIDS Vaccine Development grant from the NIAID, awarded in 2015.

Deferred grant funding recognized from Wistar and recorded as contra-research and development expense, which was classified as grant revenue in the prior year, is related to work performed by the Company on the research sub-contract agreements. For the year ended December 31, 2018, the Company recorded $3.3 million as contra-research and development expense from Wistar. For the year ended December 31, 2017, the Company recognized revenue from Wistar of $2.6 million.

Research and development expenses recorded from Wistar relate primarily to the collaborative research agreements and sub-contract agreements for the DARPA Ebola grant (see Note 4). Research and development expenses recorded from Wistar for the years ended December 31, 2018 and 2017 were $1.8 million and $2.3 million, respectively. At December 31, 2018 and 2017, the Company had an accounts receivable balance of $258,000 and $117,000, respectively, and an accounts payable and accrued liability balance of $554,000 and $820,000, respectively, related to Wistar.