Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Total revenues	$ 614,781	$ 492,625	$ 820,119
Cost of revenues
Total cost of revenues	529,552	473,258	684,738
Selling, general and administrative expenses	94,445	86,604	113,394
Other operating (income) loss, net	(391)	(3,330)	170
Impairments and other charges	0	14,727	11,422
Operating income (loss)	(8,825)	(78,634)	10,395
Foreign currency exchange (gain) loss	(397)	3,378	(816)
Interest expense, net	8,805	10,986	14,369
(Gain) loss on extinguishment of debt	1,000	(419)	0
Loss before income taxes	(18,233)	(92,579)	(3,158)
Provision (benefit) for income taxes	7,293	(11,883)	9,788
Net loss	$ (25,526)	$ (80,696)	$ (12,946)
Net loss per common share - basic (in dollars per share)	$ (0.28)	$ (0.89)	$ (0.14)
Net loss per common share - diluted (in dollars per share)	$ (0.28)	$ (0.89)	$ (0.14)
Product sales revenues
Revenues
Total revenues	$ 484,300	$ 378,813	$ 654,006
Cost of revenues
Total cost of revenues	434,405	384,519	568,388
Rental and service revenues
Revenues
Total revenues	130,481	113,812	166,113
Cost of revenues
Total cost of revenues	$ 95,147	$ 88,739	$ 116,350