CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) (in thousands) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 85,593	$ (98,292)	$ (388,671)	$ (599,439)
Other comprehensive income, net of tax:
Pension liability adjustment	246	1,195	1,029	1,573
Total other comprehensive income, net of tax	246	1,195	1,029	1,573
Total comprehensive income (loss)	$ 85,839	$ (97,097)	$ (387,642)	$ (597,866)