Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Product revenue related reserves	$ 35,069	$ 26,146
Accrued employee compensation costs	28,053	24,692
Accrued clinical and pre-clinical costs	15,595	11,396
Accrued contract manufacturing costs	15,250	15,794
Accrued professional fees	11,938	11,319
Accrued royalties	6,350	8,254
Accrued interest expense	3,183	1,045
Accrued property and equipment	2,117	5,421
Accrued research costs	778	1,070
Accrued collaboration cost sharing	541	2,167
Accrued milestone expense	152	24,020
Other	2,637	2,771
Total accrued expenses	$ 121,663	$ 134,095