Income Taxes - Reconciliation of Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax at U.S. federal statutory tax rate	$ 31,494	$ 27,005	$ 17,964
State income taxes, net of federal tax benefit	(177)	934	82
Foreign rate differential	(14,030)	(13,164)	(9,319)
Tax holidays	(4,031)	(2,749)	(4,686)
Permanent differences	11,737	10,170	9,051
Tax credits	(4,102)	(4,894)	(5,020)
Foreign withholding and other taxes	2,321	2,541	4,643
Change in valuation allowance, net of related adjustments	(631)	(7)	1,354
Changes in uncertain tax positions	(1,858)	(468)	(4)
Other	663
Total provision for income taxes	$ 21,386	$ 19,368	$ 14,065