Accumulated Other Comprehensive Income - Amounts Reclassified out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net product revenues	$ 461,097	$ 391,706	$ 1,249,605	$ 1,137,998
Total gain (loss) on cash flow hedges	4,010	(15,741)	(91,295)	(85,376)
Net product revenues
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net product revenues	450,900	386,320	1,224,458	1,123,205
Amount Reclassified from AOCI Gain (Loss) | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total gain (loss) on cash flow hedges	4,808	5,523	9,286	(2,921)
Amount Reclassified from AOCI Gain (Loss) | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Forward contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating expenses	(1,388)	498	(1,885)	3,762
Amount Reclassified from AOCI Gain (Loss) | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Net product revenues | Forward contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net product revenues	$ 6,196	$ 5,025	$ 11,171	$ (6,683)