Financial Instruments and Risk Management (Effect and Classification of Derivative Instuments) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in other comprehensive income, net of tax	$ 753	$ 3,489	$ 1,167
Designated as Hedging Instrument [Member] | Cost of Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) reclassified from accumulated other comprehensive income to income for the effective portion	5,908	(6,862)	1,789
Gain reclassified from accumulated other comprehensive income to income as a result of cash flow hedge discontinuance	441	0	0
Loss recognized in income for amount excluded from effectiveness testing and for the ineffective portion	(40)	(1,889)	(230)
Not Designated as Hedging Instrument [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in income	0	0	(130)
Not Designated as Hedging Instrument [Member] | Selling, General and Administrative Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in income	$ (1,841)	$ 1,216	$ (54)