Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 103,654	$ 76,238	$ (175,656)
Foreign currency translation adjustments	(9,276)	131,861	(319,559)
Comprehensive income (loss)	$ 94,378	$ 208,099	$ (495,215)