Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenues	$ 96,424	$ 202,763	$ 362,920	$ 630,648
Cost of revenues	99,301	169,429	357,675	522,338
Selling, general and administrative expenses	20,597	27,017	66,230	85,796
Other operating (income) loss, net	(820)	29	(1,906)	(367)
Impairments	3,038	0	3,038	0
Operating income (loss)	(25,692)	6,288	(62,117)	22,881
Foreign currency exchange loss	580	828	3,343	756
Interest expense, net	2,411	3,628	8,524	10,807
Gain on extinguishment of debt	0	0	(419)	0
Income (loss) before income taxes	(28,683)	1,832	(73,565)	11,318
Provision (benefit) for income taxes	(4,813)	3,273	(11,303)	7,171
Net income (loss)	$ (23,870)	$ (1,441)	$ (62,262)	$ 4,147
Net income (loss) per common share - basic (in dollars per share)	$ (0.26)	$ (0.02)	$ (0.69)	$ 0.05
Net income (loss) per common share - diluted (in dollars per share)	$ (0.26)	$ (0.02)	$ (0.69)	$ 0.05