KKC Agreements - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2018	Jun. 30, 2020	May 31, 2020
Receivable for foreign tax withholding		$ (20,420)
Kyowa Kirin Co
Total upfront payment receivable for grant of rights		100,000	$ 100,000
Upfront payment	$ 10,000
Receivable for foreign tax withholding		20,400
Kyowa Kirin Co | Potential Payments on Achievement of Development Regulatory and Commercial Milestones
Total upfront payment receivable for grant of rights		100,000
Kyowa Kirin Co | Potential Payments on Achievement of Development Regulatory and Commercial Milestones | Maximum
Milestone payment receivable amount		582,500
Kyowa Kirin Co | KKC License Agreement
Upfront payment		100,000
Transaction price relating to the performance obligation		191,500
Estimated development cost sharing recovered through earnings		66,300
Deferred revenue		5,200
Expected milestone payment receivable		20,000
Kyowa Kirin Co | KKC License Agreement | Ex US License
Performance obligation revenue recognised		21,000
License Obligation Account Transaction Price Allocated		64,300
Kyowa Kirin Co | KKC License Agreement | Development Services
Contract with customer liability non current		$ 18,100