CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Other Comprehensive Income [Abstract]
Net (loss) income	$ (39,808)	$ 6,815
Employee benefit plans:
Amortization of and adjustments to employee benefit costs	(4,010)	239
Income tax expense	0	(62)
Total other comprehensive (loss) income, net of tax	(4,010)	177
Total comprehensive (loss) income	$ (43,818)	$ 6,992