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Payment for license agreement.

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License Agreements - Additional Information (Detail)		1 Months Ended		9 Months Ended	12 Months Ended
License Agreements - Additional Information (Detail)	Aug. 31, 2016 USD ($)	Oct. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	May 31, 2020 USD ($)
Related Party Transaction [Line Items]
Percentage of Purchase Requirement				100.00%
License and supply agreement notice period				90 days
Profit sharing ratio				0.5
Receivable for foreign tax withholding				$ 20,420,000
Kyowa Kirin Co
Related Party Transaction [Line Items]
Upfront payment		$ 10,000,000
Total upfront payment receivable for grant of rights				100,000,000		$ 100,000,000
Receivable for foreign tax withholding				20,400,000
Kyowa Kirin Co \| Updation of Initial Assessment
Related Party Transaction [Line Items]
Estimated development cost sharing recovered through earnings				94,900,000
Kyowa Kirin Co \| Potential Payments on Achievement of Development Regulatory and Commercial Milestones
Related Party Transaction [Line Items]
Total upfront payment receivable for grant of rights					$ 10,000,000
Kyowa Kirin Co \| Potential Payments on Achievement of Development Regulatory and Commercial Milestones \| Maximum
Related Party Transaction [Line Items]
Milestone payment receivable amount				582,500,000
Helsinn License Agreement
Related Party Transaction [Line Items]
Compensation receivable for grant of rights	$ 20,000,000
Presage License Agreement \| Presage Biosciences, Inc.
Related Party Transaction [Line Items]
Compensation payable for grant of rights			$ 4,900,000
Payment for license			2,900,000
Presage License Agreement \| Presage Biosciences, Inc. \| Incremental Payment
Related Party Transaction [Line Items]
Compensation payable for grant of rights			2,000,000
Presage License Agreement \| Presage Biosciences, Inc. \| Potential Payments on Achievement of Development Regulatory and Commercial Milestones \| Maximum
Related Party Transaction [Line Items]
Milestone payments payable amount			$ 179,000,000
KKC License Agreement \| Kyowa Kirin Co
Related Party Transaction [Line Items]
Upfront payment				100,000,000
Transaction price relating to the performance obligation				191,500,000
Expected milestone payment receivable				20,000,000
Estimated development cost sharing recovered through earnings				66,300,000
Deferred revenue				5,200,000
KKC License Agreement \| Kyowa Kirin Co \| Ex US License
Related Party Transaction [Line Items]
Performance obligation revenue recognised					21,000,000
License Obligation Account Transaction Price Allocated					64,500,000
KKC License Agreement \| Kyowa Kirin Co \| Development Services
Related Party Transaction [Line Items]
Contract with customer liability non current				$ 25,400,000	$ 18,100,000