Amounts Reclassified out of AOCI (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total revenues	$ 391,706	$ 334,148	$ 1,137,998	$ 955,341
LOSS FROM OPERATIONS	(15,741)	(13,727)	(85,376)	(72,747)
Other income	2,589	267	5,266	4,282
Benefit from income taxes	(6,793)	(8,094)	(25,833)	(24,823)
NET LOSS	(12,620)	(12,527)	(73,561)	(65,650)
Net Product Revenues
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total revenues	386,320	298,752	1,123,205	916,868
Reclassified out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Benefit from income taxes	0	0	0	(1,176)
NET LOSS	5,523	(3,700)	(2,921)	1,587
Reclassified out of Accumulated Other Comprehensive Income | Gains (losses) on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
LOSS FROM OPERATIONS	5,523	(3,700)	(2,921)	(489)
Reclassified out of Accumulated Other Comprehensive Income | Gains (losses) on Cash Flow Hedges | Forward Foreign Currency Exchange Contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Operating expenses	498	943	3,762	(507)
Reclassified out of Accumulated Other Comprehensive Income | Gains (losses) on Cash Flow Hedges | Net Product Revenues | Forward Foreign Currency Exchange Contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total revenues	5,025	(4,643)	(6,683)	18
Reclassified out of Accumulated Other Comprehensive Income | Gain (Loss) on Sale of Available-for-Sale Debt Securities
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other income	0	0	0	3,252
Total gain (loss) on available-for-sale debt securities	$ 0	$ 0	$ 0	$ 2,076