Joint Venture - Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of Equity Method Investments [Line Items]
Net sales	$ 163,848	$ 188,540
Cost of materials	133,758	144,355
Net (Loss) Income	(36,870)	(15,127)
Joint venture
Schedule of Equity Method Investments [Line Items]
Net sales	31,518	52,606
Cost of materials	26,601	44,350
Income (loss) before taxes	566	1,990
Net (Loss) Income	$ 622	$ 1,750