Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Product revenue related reserves	$ 30,821	$ 26,146
Accrued employee compensation costs	23,205	24,692
Accrued clinical and pre-clinical costs	15,706	11,396
Accrued contract manufacturing costs	12,699	15,794
Accrued professional fees	8,963	11,319
Accrued royalties	5,819	8,254
Accrued property and equipment	2,902	5,421
Accrued research costs	1,733	1,070
Accrued interest expense	1,045	1,045
Accrued collaboration cost sharing	541	2,167
Accrued milestone expense	492	24,020
Other	3,402	2,771
Total accrued expenses	$ 107,328	$ 134,095