Summary of Other Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Nonoperating Income Expense [Abstract]
Interest expense	$ (15,831)	$ (13,713)	$ (31,482)	$ (27,328)
Interest income	52	638	111	2,777
Amortization of investment discount	21	999	157	3,963
Gain from sale of Priority Review Voucher	102,000		102,000	108,069
Other (expense) income, net	(427)	(371)	(499)	721
Total other income (loss)	$ 85,815	$ (12,447)	$ 70,287	$ 88,202