Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Condensed Consolidated Statements of Comprehensive Loss
Net loss	$ (48,691)	$ (41,571)	$ (61,360)	$ (73,743)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	22	(2,288)	942	1,104
Unrealized pension actuarial gains (losses), net of tax	33	256	537	32
Total other comprehensive loss, net of tax	$ (48,636)	$ (43,603)	$ (59,881)	$ (72,607)