Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Consolidated Statements of Comprehensive (Loss) Income [Abstract]
Net income (loss)	$ 16,144	$ 49,161	$ (9,702)	$ 95,994
Foreign currency translation adjustments	(27,598)	36,472	(149,057)	27,734
Comprehensive (loss) income	$ (11,454)	$ 85,633	$ (158,759)	$ 123,728