Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Income (Loss) [Abstract]
Revenues	$ 211,473	$ 227,293
Cost of revenues	174,976	186,455
Selling, general and administrative expenses	30,742	26,954
Other operating loss, net	76	46
Operating income	5,679	13,838
Foreign currency exchange (gain) loss	(1,062)	225
Interest expense, net	3,656	3,300
Income before income taxes	3,085	10,313
Provision for income taxes	1,803	3,091
Net income (loss)	$ 1,282	$ 7,222
Income (loss) per common share - basic (in dollars per share)	$ 0.01	$ 0.08
Income (loss) per common share - diluted (in dollars per share)	$ 0.01	$ 0.08