SUPPLEMENTARY DATA - QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Net sales	$ 307,294		$ 306,195	$ 330,214		$ 321,794		$ 307,809	$ 308,836	$ 376,067	$ 402,059	$ 1,265,497	$ 1,394,771	$ 1,895,527
Gross Profit	32,543		32,976	45,075		31,888		17,809	26,153	51,053	42,794	142,482	137,809	140,643
Net Income (Loss) Attributable to Parent	$ (12,984)		$ (9,952)	$ (1,899)	[1]	$ (9,152)	[2]	$ (51,160)	$ (31,476)	$ 6,771	$ 232	$ (33,987)	$ (75,633)	$ (80,461)
Earnings Per Share [Abstract]
Earnings Per Share, Basic	$ (0.26)	[3]	$ (0.21)	$ (0.07)	[1]	$ (0.27)	[2]	$ (1.07)	$ (0.79)	$ 0.17	$ (0.05)	$ (0.81)	$ (1.74)	$ (2.43)
Earnings Per Share, Diluted	$ (0.26)	[3]	$ (0.21)	$ (0.07)	[1]	$ (0.27)	[2]	$ (1.07)	$ (0.79)	$ 0.17	$ (0.05)	$ (0.81)	$ (1.74)	$ (2.43)
Mining asset impairment and inventory writedown												$ 0	$ 0	$ 39,932
Noncash goodwill impairment charge												$ 0	$ 0	$ 36,571

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