Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenues	$ 194,618	$ 236,839
Operating expenses	150,917	179,353
Gross margin	43,701	57,486
Selling, general and administrative expenses	66,124	78,444
Restructuring and other related charges, net	1,877	186
Goodwill impairment charge	0	191,788
Operating loss	(24,300)	(212,932)
Interest expense, net	(9,396)	(6,776)
Other expense, net	(950)	(472)
Loss before income taxes	(34,646)	(220,180)
Benefit for income taxes	355	20,453
Net loss	$ (34,291)	$ (199,727)
Loss per common share:
Basic (in dollars per share)	$ (1.11)	$ (6.54)
Diluted (in dollars per share)	$ (1.11)	$ (6.54)
Weighted-average number of shares outstanding:
Weighted-average number of basic shares outstanding (in shares)	30,878	30,540
Weighted-average number of diluted shares outstanding (in shares)	30,878	30,540