Commitments and Contingencies	9 Months Ended
Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	4. Commitments and Contingencies Litigation In the ordinary course of business, the Company is from time to time involved in lawsuits, claims, investigations, proceedings, and threats of litigation relating to intellectual property, commercial arrangements, employment and other matters. While the outcome of those proceedings and claims cannot be predicted with certainty, the Company is not party to any legal or arbitration proceedings that may have significant effects on its financial position. It is not a party to any material proceedings in which any director, member of executive management or affiliate of the Company is either a party adverse to it or its subsidiaries or has a material interest adverse to it or its subsidiaries. As disclosed in its Current Report on Form 8-K filed with the SEC on June 26, 2019, on June 25, 2019, the Company received notification that the United States Patent and Trademark Office initiated an interference proceeding at the Patent Trial and Appeal Board (the “PTAB”) between certain pending U.S. patent applications co-owned by the University of California, the University of Vienna and Dr. Emmanuelle Charpentier (collectively, the “CVC Group”) and certain patents and a patent application currently owned by the Broad Institute and Massachusetts Institute of Technology and, in some instances, the President and Fellows of Harvard College (individually and collectively, the “Broad”), all of which are related to the single guide format of CRISPR/Cas9 genome editing technology in eukaryotic cells. The Company has an exclusive worldwide license in the field of human therapeutics to Dr. Charpentier’s rights as a co-owner of the CVC Group portfolio. Specifically, the PTAB has declared Patent Interference No. 106,115 between the CVC Group’s pending U.S. Patent Application Nos. 15/947,680; 15/947,700; 15/947,718; 15/981,807; 15/981,808; 15/981,809; 16/136,159; 16/136,165; 16/136,168; and 16/136,175, and the Broad’s U.S. Patent Nos. 8,697,359; 8,771,945; 8,795,965; 8,865,406; 8,871,445; 8,889,356; 8,895,308; 8,906,616; 8,932,814; 8,945,839; 8,993,233; 8,999,641; 9,840,713, and U.S. Patent Application No. 14/704,551. Letters of Credit As of September 30, 2019, the Company had restricted cash of $3.9 million representing letters of credit securing the Company’s obligations under certain leased facilities in Cambridge, Massachusetts, as well as certain credit card arrangements. The letters of credit are secured by cash held in a restricted depository account. The cash deposit is recorded in restricted cash in the accompanying consolidated balance sheet as of September 30, 2019. Research Agreements The Company has engaged several research institutions and companies to identify new delivery strategies and applications of its gene-editing technology. The Company is also a party to a number of research license agreements which require significant upfront payments, future royalty payments and potential milestone payments from time to time, as well as intellectual property agreements, which require maintenance and milestone payments from time to time. In association with these agreements, the Company has committed to making payments of $1.4 million and $2.3 million in the fourth quarter of 2019 and for the year ended December 31, 2020, respectively. For the three and nine months ended September 30, 2019, the Company paid $0.2 million and $2.4 million, respectively, related to these research agreements. For the three and nine months ended September 30, 2018, the Company paid $0.3 million and $1.4 million, respectively, related to these research agreements. The Company is also a party to a number of manufacturing agreements that require upfront payments for the future performance of services. In connection with these agreements, the Company paid $2.2 million in upfront payments, which were recorded as prepaid expenses as of September 30, 2019. The Company will amortize the prepaid balance as services are performed.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2019

Commitments And Contingencies Disclosure [Abstract]

4. Commitments and Contingencies

Litigation

In the ordinary course of business, the Company is from time to time involved in lawsuits, claims, investigations, proceedings, and threats of litigation relating to intellectual property, commercial arrangements, employment and other matters. While the outcome of those proceedings and claims cannot be predicted with certainty, the Company is not party to any legal or arbitration proceedings that may have significant effects on its financial position. It is not a party to any material proceedings in which any director, member of executive management or affiliate of the Company is either a party adverse to it or its subsidiaries or has a material interest adverse to it or its subsidiaries.

As disclosed in its Current Report on Form 8-K filed with the SEC on June 26, 2019, on June 25, 2019, the Company received notification that the United States Patent and Trademark Office initiated an interference proceeding at the Patent Trial and Appeal Board (the “PTAB”) between certain pending U.S. patent applications co-owned by the University of California, the University of Vienna and Dr. Emmanuelle Charpentier (collectively, the “CVC Group”) and certain patents and a patent application currently owned by the Broad Institute and Massachusetts Institute of Technology and, in some instances, the President and Fellows of Harvard College (individually and collectively, the “Broad”), all of which are related to the single guide format of CRISPR/Cas9 genome editing technology in eukaryotic cells. The Company has an exclusive worldwide license in the field of human therapeutics to Dr. Charpentier’s rights as a co-owner of the CVC Group portfolio. Specifically, the PTAB has declared Patent Interference No. 106,115 between the CVC Group’s pending U.S. Patent Application Nos. 15/947,680; 15/947,700; 15/947,718; 15/981,807; 15/981,808; 15/981,809; 16/136,159; 16/136,165; 16/136,168; and 16/136,175, and the Broad’s U.S. Patent Nos. 8,697,359; 8,771,945; 8,795,965; 8,865,406; 8,871,445; 8,889,356; 8,895,308; 8,906,616; 8,932,814; 8,945,839; 8,993,233; 8,999,641; 9,840,713, and U.S. Patent Application No. 14/704,551.

Letters of Credit

As of September 30, 2019, the Company had restricted cash of $3.9 million representing letters of credit securing the Company’s obligations under certain leased facilities in Cambridge, Massachusetts, as well as certain credit card arrangements. The letters of credit are secured by cash held in a restricted depository account. The cash deposit is recorded in restricted cash in the accompanying consolidated balance sheet as of September 30, 2019.

Research Agreements

The Company has engaged several research institutions and companies to identify new delivery strategies and applications of its gene-editing technology. The Company is also a party to a number of research license agreements which require significant upfront payments, future royalty payments and potential milestone payments from time to time, as well as intellectual property agreements, which require maintenance and milestone payments from time to time. In association with these agreements, the Company has committed to making payments of $1.4 million and $2.3 million in the fourth quarter of 2019 and for the year ended December 31, 2020, respectively. For the three and nine months ended September 30, 2019, the Company paid $0.2 million and $2.4 million, respectively, related to these research agreements. For the three and nine months ended September 30, 2018, the Company paid $0.3 million and $1.4 million, respectively, related to these research agreements.

The Company is also a party to a number of manufacturing agreements that require upfront payments for the future performance of services. In connection with these agreements, the Company paid $2.2 million in upfront payments, which were recorded as prepaid expenses as of September 30, 2019. The Company will amortize the prepaid balance as services are performed.