Derivative Instruments and Hedging Strategies - Summary of Impact of Gains and Losses from Derivatives Designated as Hedging Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Net product revenues	$ 476,784	$ 461,097	$ 1,408,338	$ 1,249,605
Operating expenses as reported	532,725	457,087	1,400,263	1,340,900
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Earnings	4,166	(1,286)	9,600	(5,182)
Operating expenses as reported | Derivatives Designated As Hedging Instruments | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Gains (Losses) Reclassified into Earnings	(815)	(1,388)	(4,274)	(1,885)
Net product revenues
Derivative Instruments, Gain (Loss) [Line Items]
Net product revenues	460,741	450,900	1,368,816	1,224,458
Net product revenues | Derivatives Designated As Hedging Instruments | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Gains (Losses) Reclassified into Earnings	$ 2,693	$ 6,196	$ 17,301	$ 11,171