Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Consolidated Statements of Comprehensive Income [Abstract]
Net (loss) income	$ (57,391)	$ 9,233	$ (25,846)	$ 46,832
Foreign currency translation adjustments	(121,810)	(36,023)	(121,459)	(8,738)
Comprehensive (loss) income	$ (179,201)	$ (26,790)	$ (147,305)	$ 38,094