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Collaborations (Details)	1 Months Ended							3 Months Ended		12 Months Ended
Collaborations (Details)	Oct. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Aug. 31, 2020 USD ($)	Nov. 30, 2018 USD ($)	Feb. 28, 2014 USD ($)	Jun. 30, 2013 USD ($)	Jul. 31, 2012 target	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2019 USD ($)	Nov. 30, 2020 USD ($)
Revenue under collaborations
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues								$ 0	$ 0
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
Potential revenue through milestone payments				$ 6,800,000
Agreement period				24 months
Upfront payment non-creditable portion recognized										$ 6,800,000
Enrollment Milestone			10,000,000
Contract with customer, asset											$ 5,000,000
Development milestone not achievable								$ 25,000,000
Sanofi \| Minimum \| United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales								10.00%
Sanofi \| Minimum \| Outside of the United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales								10.00%
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 United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalties based on percentage of net sales								20.00%
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]
Potential revenue through milestone payments								38,800,000
Sanofi \| Clinical
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential revenue through milestone payments								25,000,000
Sanofi \| Regulatory and Commercialization Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential revenue through milestone payments								$ 130,000,000
Sanofi \| Development Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential revenue through milestone payments			25,000,000	$ 40,000,000
Sanofi \| Enrollment Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential revenue through milestone payments				$ 10,000,000
Sanofi \| Materials Sold
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential revenue through milestone payments			4,000,000
Sanofi \| Achievement of Enrollment Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential revenue through milestone payments			$ 5,000,000