Subsequent Events	9 Months Ended
Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events In October 2021, the Company and SparingVision SAS (“SparingVision”), a genomic medicine company developing vision saving treatments for ocular diseases, announced a strategic collaboration to develop novel genomic medicines utilizing CRISPR/Cas9 technology for the treatment of ocular diseases. The Company will grant SparingVision exclusive rights to its proprietary in vivo CRISPR/Cas9-based genome editing technology for up to three ocular targets addressing diseases with significant unmet medical need. SparingVision will lead and fund the preclinical and clinical development for the genome editing product candidates pursued under the collaboration. In addition, the parties will research and develop novel self-inactivating adeno-associated virus (“AAV”) vectors and lipid nanoparticle-based approaches to address delivery of CRISPR/Cas9 genome editing reagents to the retina. The Company will receive a 10% equity ownership stake in SparingVision. The Company will also be eligible to receive certain development and commercial milestone payments (up to approximately $200 million per product) as well as royalties on potential future sales of products arising from the collaboration. The Company will have an option to obtain exclusive U.S. commercialization rights for product candidates arising from two of three collaboration targets. For product candidates the Company chooses to option, it will pay an opt-in fee, reimburse certain costs, share in 50% of development costs and pay royalties to SparingVision on U.S. sales.

Subsequent Events

9 Months Ended

Sep. 30, 2021

14. Subsequent Events

In October 2021, the Company and SparingVision SAS (“SparingVision”), a genomic medicine company developing vision saving treatments for ocular diseases, announced a strategic collaboration to develop novel genomic medicines utilizing CRISPR/Cas9 technology for the treatment of ocular diseases. The Company will grant SparingVision exclusive rights to its proprietary in vivo CRISPR/Cas9-based genome editing technology for up to three ocular targets addressing diseases with significant unmet medical need. SparingVision will lead and fund the preclinical and clinical development for the genome editing product candidates pursued under the collaboration. In addition, the parties will research and develop novel self-inactivating adeno-associated virus (“AAV”) vectors and lipid nanoparticle-based approaches to address delivery of CRISPR/Cas9 genome editing reagents to the retina. The Company will receive a 10% equity ownership stake in SparingVision. The Company will also be eligible to receive certain development and commercial milestone payments (up to approximately $200 million per product) as well as royalties on potential future sales of products arising from the collaboration. The Company will have an option to obtain exclusive U.S. commercialization rights for product candidates arising from two of three collaboration targets. For product candidates the Company chooses to option, it will pay an opt-in fee, reimburse certain costs, share in 50% of development costs and pay royalties to SparingVision on U.S. sales.