CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) (in thousands) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (222,995)	$ (89,252)	$ (474,264)	$ (501,147)
Other comprehensive income, net of tax:
Pension liability adjustment	592	188	783	378
Total other comprehensive income, net of tax	592	188	783	378
Total comprehensive loss	$ (222,403)	$ (89,064)	$ (473,481)	$ (500,769)