Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Income Statement [Abstract]
Revenues	$ 219,093	$ 290,079	$ 645,236	[1]	$ 875,507	[1]
Operating expenses	155,388	207,044	466,669		631,928
Gross margin	63,705	83,035	178,567		243,579
Selling, general and administrative expenses	61,089	84,647	198,415		248,507
Restructuring and other related charges, net	319	228	3,365		436
Goodwill impairment charge	0	0	191,788		0
Operating income (loss)	2,297	(1,840)	(215,001)		(5,364)
Interest expense, net	7,757	7,647	21,847		22,658
Other expense, net	655	116	1,292		371
Loss before income taxes	(6,115)	(9,603)	(238,140)		(28,393)
Less: Provision (benefit) for income taxes	2,958	(2,546)	(15,812)		(3,210)
Net loss	$ (9,073)	$ (7,057)	$ (222,328)		$ (25,183)
Loss per common share:
Basic (in dollars per share)	$ (0.30)	$ (0.23)	$ (7.27)		$ (0.83)
Diluted (in dollars per share)	$ (0.30)	$ (0.23)	$ (7.27)		$ (0.83)
Weighted-average number of shares outstanding:
Basic (in shares)	30,628	30,300	30,599		30,267
Diluted (in shares)	30,628	30,300	30,599		30,267

[1] Revenues attributable to individual countries/geographic areas are based on the country of domicile of the legal entity that performs the work.