Derivative Commodity Instruments (Impact Of Derivative Instruments Not Designated As Fair Value Hedges) (Details) (Commodity Forward Contracts [Member], Derivatives Not Designated As Hedging Instrument [Member], Cost of Sales [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commodity Forward Contracts [Member] | Derivatives Not Designated As Hedging Instrument [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ (9,678)	$ 5,438	$ (11,626)