CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Revenues	$ 189,095	$ 406,270
Cost of revenues (exclusive of items shown below)	161,256	292,445
Selling, general and administrative expenses	43,546	42,433
Depreciation and amortization	60,636	65,976
Gain on disposition of assets, net	(1,256)	(958)
Operating (loss) profit	(75,087)	6,374
Interest expense	(325)	(691)
Interest income	23	6
Other income, net	342	5,585
(Loss) income before income taxes	(75,047)	11,274
Income tax (benefit) provision	(42,536)	3,726
Net (loss) income	$ (32,511)	$ 7,548
(Loss) earnings per share
Basic (in dollars per share)	$ (0.15)	$ 0.04
Diluted (in dollars per share)	$ (0.15)	0.04
Dividends per share		$ 0.105