Collaborations (Details)	1 Months Ended						12 Months Ended
	Oct. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Aug. 31, 2020 USD ($)	Nov. 30, 2018 USD ($)	Feb. 28, 2014 USD ($)	Jul. 31, 2012 target	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Nov. 30, 2020 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue							$ 0	$ 10,006,000
Contract with customer, asset										$ 5,000,000
Development Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments			$ 25,000,000
Materials Sold
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments			4,000,000
Achievement of Enrollment Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments			5,000,000
Strategic Alliances and Collaborations
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue							0	$ 10,000,000
Sanofi
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of collaborative areas granted | target						4
Initial upfront option payment	$ 4,000,000	$ 1,000,000	1,000,000
Expected revenue through milestone payments				$ 6,800,000
Agreement period				24 months
Milestone payments, earned									$ 6,800,000
Enrollment milestone			$ 10,000,000
Development milestone not achievable							25,000,000
Sanofi | Development Commercialization And License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue creditable against future milestones					$ 1,250,000		1,250,000
Initial upfront option payment					$ 2,500,000
Sanofi | Proof-of-Concept Trial
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments							38,800,000
Sanofi | Clinical
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments							25,000,000
Sanofi | Regulatory and Commercialization Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments							$ 130,000,000
Sanofi | Development Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments				$ 40,000,000
Sanofi | Enrollment Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected revenue through milestone payments				$ 10,000,000
Sanofi | Minimum | United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales							1000.00%
Sanofi | Minimum | Outside of the US
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales							1000.00%
Sanofi | Maximum | United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales							20.00%
Sanofi | Maximum | Outside of the US
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales							20.00%