Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Consolidated Statements of Comprehensive Loss
Net Loss	$ (133,427)	$ (28,940)	$ (197,479)	$ (78,116)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	(2,325)	(2,492)	(1,221)	(3,639)
Unrealized pension actuarial gains (losses), net of tax	291	140	323	363
Total other comprehensive loss, net of tax	$ (135,461)	$ (31,292)	$ (198,377)	$ (81,392)