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, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Expected tax expense	$ 29,361	$ 26,521	$ 12,797
Change in valuation allowance	22	19	64
Impact of tax holiday	(4,027)	(2,991)	(3,208)
Foreign tax rate differential	(2,716)	(2,797)	(3,327)
Deferred tax (benefit)/provision	(878)	(803)	(459)
Unrecognized tax benefits and interest	495	324	(1,846)
State taxes, net of Federal taxes	202	1,327	593
Non-deductible expenses	144	26	15
Prior year tax expense/(benefit)		2,450
Other	(452)	135	564
Income tax expense	$ 22,151	$ 24,211	$ 5,193