Derivative Instruments and Hedging Activities Location of Gain Loss in Income Statement (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Derivatives, Net	$ 15,501	$ 12,868	$ 3,219
Cost of products sold
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Derivatives, Net	20,751	12,295	3,219
Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Derivatives, Net	$ (5,250)	$ 573	$ 0