Equity Method Investments - Operating Results (Details) (ICP [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
ICP [Member]
Schedule of Equity Method Investments [Line Items]
Net sales	$ 236,486	$ 193,682
Cost of sales and expenses	(196,551)	(194,519)
Net income (loss)	$ 39,935	$ (837)