Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Product revenue related reserves	$ 44,798	$ 45,249
Accrued contract manufacturing costs	42,583	27,622
Accrued employee compensation costs	34,535	43,240
Accrued clinical and pre-clinical costs	26,955	18,010
Accrued professional fees	10,508	10,707
Accrued milestone expense	9,388	18,390
Accrued property and equipment	8,055	1,181
Accrued royalties	7,813	6,301
Accrued collaboration cost sharing	6,463	9,000
Accrued interest expense	3,182	1,045
Other	4,783	4,782
Total accrued expenses	$ 199,063	$ 185,527