Collaboration and License Agreements - Takeda Pharmaceuticals U.S.A., Inc - Additional Information (Detail) - Takeda License Agreement - License and Co-Funding Agreement - Subsequent Event $ in Millions	Oct. 07, 2020 USD ($) Obligation Bundle
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement date	Oct. 07, 2020
Ratio of Profit Sharing Structure for United States Commercialization	50/50 profit sharing
Cash received as due under collaboration agreement	$ 300.0
Development regulatory and sales milestones payments	$ 740.0
Number of distinct bundle | Bundle	1
Number of distinct performance obligations | Obligation	1
Initial transaction price	$ 300.0
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of eligible to receive tiered royalties on net sales	20.00%
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of eligible to receive tiered royalties on net sales	25.00%
Development regulatory and sales milestones payments	$ 740.0