Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Reserves and accruals	$ 24,136	$ 27,673
Stock-based compensation expense	2,524	1,960
Unrealized losses	1,471	10,768
Operating loss carryforwards	49,169	95,864
Gross deferred tax assets	77,300	136,265
Valuation allowance	(57,003)	(84,573)	$ (29,167)	$ (29,894)
Total deferred tax assets, net	20,297	51,692
Deferred tax liabilities:
Property, plant and equipment	(50,610)	(65,825)
Intangible assets	(159,237)	(172,123)
Total deferred tax liabilities	(209,847)	(237,948)
Net deferred tax liabilities	$ (189,550)	$ (186,256)