CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues	$ 20,241	$ 75,807	$ 73,993	$ 222,806
Cost of sales	41,106	80,404	138,512	263,703
Gross loss	(20,865)	(4,597)	(64,519)	(40,897)
Selling, general and administrative expenses	9,640	14,609	31,148	45,902
(Gain) loss on disposal or impairment of assets	(15)	15	910	(148)
Operating loss	(30,490)	(19,221)	(96,577)	(86,651)
Other expense:
Interest expense, net	(1,440)	(204)	(3,859)	(234)
Other, net	50	140	133	35
Nonoperating income (expense), total	(1,390)	(64)	(3,726)	(199)
Loss before income taxes	(31,880)	(19,285)	(100,303)	(86,850)
Income tax benefit	(11,930)	(5,387)	(35,373)	(27,346)
Net loss	$ (19,950)	$ (13,898)	$ (64,930)	$ (59,504)
Loss per share:
Basic	$ (0.81)	$ (0.60)	$ (2.75)	$ (2.59)
Diluted	$ (0.81)	(0.60)	$ (2.75)	(2.59)
Other information:
Dividends declared per common share		$ 0.20		$ 0.63