Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Reserves and accruals	$ 27,673	$ 11,276
Stock-based compensation expense	1,960	1,752
Unrealized losses	10,768	0
Operating loss carryforwards	95,864	37,594
Others, net	0	5
Gross deferred tax assets	136,265	50,627
Valuation allowance	(84,573)	(29,167)	$ (29,894)	$ (27,181)
Total deferred tax assets, net	51,692	21,460
Deferred tax liabilities:
Property, plant and equipment	(65,825)	(57,006)
Unrealized gains	0	(7,832)
Intangible assets	(172,123)	(168,655)
Total deferred tax liabilities	(237,948)	(233,493)
Net deferred tax liabilities	$ (186,256)	$ (212,033)