Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income (loss) before income taxes
Domestic	$ 27,461	$ (1,738)	$ 32,903
Foreign	58,630	(24,133)	(132,857)
Income (loss) before income tax expenses	86,091	(25,871)	(99,954)
Current income taxes expense (benefit)
Domestic	(359)	(6)	25
Foreign	3,680	3,386	(14,301)
Uncertain tax position liability	(2,111)	351	(1,211)
Current income taxes expense	1,210	3,731	(15,486)
Deferred income taxes expense (benefit)
Foreign	(55)	13	399
Income tax expense (benefit)	$ 1,155	$ 3,744	$ (15,087)
Effective tax rate	1.30%	(14.50%)	15.10%
Domestic [Member]
Current income taxes expense (benefit)
Uncertain tax position liability	$ (476)	$ 12	$ 10
Foreign [Member]
Current income taxes expense (benefit)
Uncertain tax position liability	$ (1,635)	$ 339	$ (1,220)