Income Taxes - Reconciliation of Federal Income Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax computed at U.S. federal statutory rate	$ 14,109	$ (8,195)	$ (38,558)
State taxes, net of federal benefit	122	98	64
Tax rate differential for international subsidiaries	(5,005)	(41,429)	23,532
Stock-based compensation	(108,023)	(93,073)	(116,953)
Tax credits	(51,237)	(44,695)	(21,038)
Foreign restructuring and amortization	0	(625,292)	2,794
Non-deductible expenses	21,953	9,657	2,833
Tax effects associated with Topic 606	0	(23,073)	3,314
Other	448	408	607
Valuation allowance	(431,880)	813,274	146,845
(Benefit from) provision for income taxes	$ (559,513)	$ (12,320)	$ 3,440