Equity Method Investments - Operating Results (Details) (ICP [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
ICP [Member]
Schedule of Equity Method Investments [Line Items]
Net sales	$ 39,598	$ 58,849
Cost of sales and expenses	35,169	48,027
Net income	$ 4,429	$ 10,822