Derivative Instruments And Hedging Activities (Gain/(Loss) On Derivative Cash Flow Hedges Recognized In OCI) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in OCI	$ (1,524)	$ (12,378)	$ (8,477)
Cash Flow Hedges [Member] | Foreign Currency Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Recognized in OCI	(304)	(6,896)	(4,402)
Cash Flow Hedges [Member] | Natural Gas Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Recognized in OCI	(558)	(1,164)	(1,329)
Unsecured Commercial Paper [Member] | Cash Flow Hedges [Member] | Interest Rate Swaps-Unsecured Commercial Paper [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Recognized in OCI	(662)	(4,318)	(1,299)
Conduit Facility [Member] | Cash Flow Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Recognized in OCI			$ (1,447)