CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Revenues	$ 20,651	$ 73,252	$ 53,753	$ 146,999
Cost of sales	40,663	83,554	97,406	183,299
Gross loss	(20,012)	(10,302)	(43,653)	(36,300)
Selling, general and administrative expenses	10,034	14,746	21,509	31,292
(Gain) loss on disposal or impairment of assets	(23)	(131)	925	(163)
Operating loss	(30,023)	(24,917)	(66,087)	(67,429)
Other expense:
Interest expense, net	(1,623)	(29)	(2,419)	(31)
Other, net	8	25	83	(105)
Nonoperating income (expense), total	(1,615)	(4)	(2,336)	(136)
Loss before income taxes	(31,638)	(24,921)	(68,423)	(67,565)
Income tax benefit	(11,342)	(7,917)	(23,443)	(21,959)
Net loss	$ (20,296)	$ (17,004)	$ (44,980)	$ (45,606)
Loss per share:
Basic	$ (0.88)	$ (0.74)	$ (1.95)	$ (1.98)
Diluted	$ (0.88)	$ (0.74)	$ (1.95)	(1.98)
Other information:
Dividends declared per common share				$ 0.43