CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (110,664)	$ (129,188)
Other comprehensive income:
Change in pension plan and supplemental pension plan liability, net of tax of $0.2 million and $0.2 million, respectively	448	817
Total comprehensive loss	$ (110,216)	$ (128,371)