Joint Venture - Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule of Equity Method Investments [Line Items]
Net sales	$ 199,703	$ 249,492	$ 421,931	$ 502,902
Cost of materials	172,402	191,565	340,513	380,096
Income (loss) before taxes	(57,189)	(78,395)	(78,720)	(94,444)
Net (Loss) Income	(58,920)	(72,298)	(79,626)	(88,296)
Joint venture
Schedule of Equity Method Investments [Line Items]
Net sales	41,014	62,608	93,620	127,859
Cost of materials	35,045	52,100	79,395	106,403
Income (loss) before taxes	760	4,639	2,750	9,443
Net (Loss) Income	$ 902	$ 3,588	$ 2,652	$ 7,402