Income Taxes - Summary of Effective Income Tax Rate Differs from Amount Computed by Applying U.S. Federal Statutory Income Tax Rate to Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Expected tax expense	$ 26,521	$ 12,797	$ 22,742
Change in valuation allowance	19	64	0
Impact of tax holiday	(2,991)	(3,208)	(5,531)
Foreign tax rate differential	(2,797)	(3,327)	(1,412)
Deferred tax (benefit)/provision	(803)	(459)	(433)
Unrecognized tax benefits and interest	324	(1,846)	2,399
State taxes, net of Federal taxes	1,327	593	601
Non-deductible expenses	26	15	310
Prior year tax expense/(benefit)	2,450	0	(875)
Other	135	564	(921)
Income tax expense	$ 24,211	$ 5,193	$ 16,880