Recent Accounting Pronouncements - Summary of Adjustments to Accounts on Condensed Consolidated Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Recent Accounting Pronouncements [Line Items]
Net product revenues		$ 372,845	$ 317,448	$ 746,292		$ 621,193
Benefit from income taxes		(12,385)	(8,713)	(19,040)		(16,729)
Net loss		(16,792)	(36,833)	(60,941)		(53,123)
Net Product Revenues
Recent Accounting Pronouncements [Line Items]
Net product revenues		367,786	$ 315,926	736,885		$ 618,116
Adjustments
Recent Accounting Pronouncements [Line Items]
Benefit from income taxes	[1]	11		(6,225)
Net loss	[1]	37		(20,925)	[2]
Adjustments | Net Product Revenues
Recent Accounting Pronouncements [Line Items]
Net product revenues	[1]	48		(27,150)
Balance Without Adoption of ASC 606
Recent Accounting Pronouncements [Line Items]
Benefit from income taxes		(12,374)		(25,265)
Net loss		(16,755)		(81,866)
Balance Without Adoption of ASC 606 | Net Product Revenues
Recent Accounting Pronouncements [Line Items]
Net product revenues		$ 367,834		$ 709,735

[1] The adoption of ASC 606 resulted in additional revenues recognized in the first half of 2018, which in turn generated additional deferred tax liabilities that reduced the Company's benefit from income taxes. The Benefit from Income Taxes amount has been calculated using the Company’s estimated statutory rate.

[2] The adoption of ASC 606 resulted in decreased Net Loss and increased Accounts Receivable, Net due to additional revenues recognized in the first quarter of 2018, which in turn generated additional deferred tax liabilities that reduced the Company's net Deferred Tax Assets. The Deferred Income Taxes amount has been calculated using the Company’s estimated statutory rate.