CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenues	$ 103,051	$ 279,574	$ 648,325
Cost of sales	188,065	335,699	467,045
Gross (loss) profit	(85,014)	(56,125)	181,280
Selling, general and administrative expenses	39,984	62,199	72,535
Start-up costs	15	797	811
Loss on disposal or impairment of assets, net	889	44,111	15,079
Operating (loss) profit	(125,902)	(163,232)	92,855
Other (expense) income:
Interest (expense) income, net	(5,435)	(470)	597
Foreign currency exchange gain (loss), net	119	94	(303)
Other, net	10	(141)	(278)
Nonoperating income (expense), total	(5,306)	(517)	16
(Loss) income before income taxes	(131,208)	(163,749)	92,871
Income tax (benefit) expense	(51,081)	(54,205)	37,283
Net (loss) income	$ (80,127)	$ (109,544)	$ 55,588
(Loss) earnings per share:
Basic	$ (3.29)	$ (4.76)	$ 2.41
Diluted	$ (3.29)	$ (4.76)	$ 2.41