CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (81,297)	$ (409,086)	$ 40,809
Other comprehensive income (loss):
Other post retirement benefits income (loss), net of tax	6,244	(4,324)	(2,091)
Total other comprehensive income (loss), net of tax	6,244	(4,324)	(2,091)
Comprehensive income (loss)	$ (75,053)	$ (413,410)	$ 38,718