Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Condensed Consolidated Statements of Comprehensive Loss
Net loss	$ (28,318)	$ (131,289)	$ (89,677)	$ (205,032)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	343	(2,325)	1,285	(1,221)
Unrealized pension actuarial gains (losses), net of tax	(332)	291	205	323
Total other comprehensive loss, net of tax	$ (28,307)	$ (133,323)	$ (88,187)	$ (205,930)