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)	$ 411,778	$ (711,777)	$ (1,716,297)
Postretirement benefits:
Actuarial gain (loss)	62	39	(532)
Amortization of prior service costs	369	369	369
Income tax (expense) benefit	(102)	(99)	33
Total comprehensive income (loss)	$ 412,107	$ (711,468)	$ (1,716,427)