Derivative Instruments (Impact of Derivative Instruments on Income) (Details) (Cost of Sales, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Designated As Fair Value Hedges | Firm Commitment Derivative Items Designated As Hedged Item
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 236	$ 515	$ 15	$ (13,546)
Designated As Fair Value Hedges | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	(232)	(515)	(342)	12,345
Derivatives Not Designated As Hedging Instruments | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 4,854	$ 249	$ 9,897	$ (783)