Related Party Transactions	9 Months Ended
Related Party Transactions	Sep. 30, 2020
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transactions	Related Party Transactions GeneOne Life Sciences On August 27, 2020, the Company sold 1,644,155 shares of common stock in GeneOne for net proceeds of approximately 47.4 billion KRW (approximately USD $40.1 million based on the exchange rate on the date of sale). The Company no longer holds an investment in GeneOne shares and GeneOne is no longer considered a related party to the Company under ASC 850. The Company's condensed consolidated balance sheet as of September 30, 2020 no longer reflects GeneOne’s portion in accounts receivable and accounts payable and accrued expenses with affiliated entities whereas the Company’s balance sheet as of December 31, 2019 reflects $128,000 and $511,000 in accounts receivable and accounts payable and accrued expenses with affiliated entities, respectively, related to GeneOne. Revenues recognized from GeneOne will no longer be presented as revenue with affiliated entity on the consolidated statement of operations after the change in related party designation in August 2020. 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. Revenue recognized from GeneOne consisted of patent and device maintenance fees. For both the three and nine months ended September 30, 2020 and 2019, the Company recognized revenue from GeneOne of $31,000 and $94,000, respectively. Operating expenses recorded from transactions with GeneOne related primarily to biologics manufacturing were $1.6 million and $4.4 million for the three and nine months ended September 30, 2020, respectively, and $232,000 and $2.1 million for the three and nine months ended September 30, 2019, respectively. Plumbline Life Sciences, Inc. The Company owns 597,808 shares of common stock in Plumbline Life Sciences, Inc. ("PLS") as of September 30, 2020 and one of the Company's directors, Dr. David B. Weiner, acts as a consultant to PLS. On February 20, 2020, the Company entered into a Debt and Share Subscription Agreement with PLS under which the Company received 202,050 shares of PLS common stock in exchange for a portion of the outstanding accounts receivable balance due from PLS. Following the issuance of these shares and as of September 30, 2020, the Company held a 19.9% ownership interest in PLS. Revenue recognized from PLS consists of milestone, license and patent fees. For the three and nine months ended September 30, 2020, the Company recognized revenue from PLS of $83,000 and $1.3 million, respectively, and $22,000 and $86,000 for the three and nine months ended September 30, 2019, respectively. At September 30, 2020 and December 31, 2019, the Company had an accounts receivable balance of $40,000 and $589,000, respectively, related to PLS. The Wistar Institute The Company's director Dr. David B. Weiner is a director of the Vaccine Center of The Wistar Institute ("Wistar"). Dr. Weiner is also the Executive Vice President of 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 under the agreement. In November 2016, the Company received a $6.1 million sub-grant through Wistar to develop a DNA-based monoclonal antibody against the Zika infection, with funding through December 2020. The Company is also a collaborator with Wistar on an Integrated Preclinical/Clinical AIDS Vaccine Development grant from the NIAID, with funding through February 2021. Deferred grant funding recognized from Wistar and recorded as contra-research and development expense is related to work performed by the Company on the research sub-contract agreements. For the three and nine months ended September 30, 2020, the Company recorded $1.0 million and $1.7 million, respectively, and for the three and nine months ended September 30, 2019 the Company recorded $482,000 and $1.7 million, respectively, as contra-research and development expense from Wistar. Research and development expenses recorded from Wistar relate primarily to the collaborative research agreements and sub-contract agreements related to the Bill and Melinda Gates Foundation and CEPI (see Note 15). Research and development expenses recorded from Wistar for the three and nine months ended September 30, 2020 were $411,000 and $1.2 million, respectively. Research and development expenses recorded from Wistar for the three and nine months ended September 30, 2019 were $313,000 and $1.1 million, respectively. At September 30, 2020 and December 31, 2019, the Company had an accounts receivable balance of $443,000 and $616,000, respectively, and an accounts payable and accrued liability balance of $795,000 and $219,000, respectively, related to Wistar. As of September 30, 2020, the Company had $173,000 recorded as deferred grant funding on the condensed consolidated balance sheet related to Wistar.