Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Income (Loss) [Abstract]
Revenues	$ 104,554	$ 154,170	$ 334,413	$ 526,278
Cost of revenues	99,293	138,283	313,669	457,072
Selling, general and administrative expenses	21,736	25,859	66,663	75,800
Other operating income, net	(1,420)	(709)	(3,829)	(1,777)
Impairments and other charges	0	0	6,925	0
Operating loss	(15,055)	(9,263)	(49,015)	(4,817)
Foreign currency exchange (gain) loss	761	3,236	(440)	4,390
Interest expense, net	2,127	2,129	7,230	6,608
Gain on extinguishment of debt	0	0	(1,894)	0
Loss from operations before income taxes	(17,943)	(14,628)	(53,911)	(15,815)
Benefit for income taxes	(4,492)	(10,157)	(13,256)	(8,083)
Net loss	$ (13,451)	$ (4,471)	$ (40,655)	$ (7,732)
Loss per common share - basic (in dollars per share)	$ (0.16)	$ (0.05)	$ (0.49)	$ (0.09)
Loss per common share - diluted (in dollars per share)	$ (0.16)	$ (0.05)	$ (0.49)	$ (0.09)