Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (62,371)	$ (437,012)
Other comprehensive loss, net of tax:
Currency translation adjustments (net of income tax of $0 in 2019 and 2018)	7,250	(19,366)
Change in unrecognized net periodic pension costs (net of income tax benefit of $2,299 in 2019 and income tax of $1,377 in 2018)	(6,545)	3,920
Net unrealized loss on derivative instruments and other (net of income tax benefit of $3,305 in 2019 and $1,831 in 2018)	(7,800)	(5,082)
Other comprehensive loss	(7,095)	(20,528)
Comprehensive loss	$ (69,466)	$ (457,540)