Derivative Instruments (Amount Of (Gain) Or Loss Recognized In OCI On Derivatives (Effective Portion) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in OCI on Derivatives (Effective Portion)	$ 223	$ 663
Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in OCI on Derivatives (Effective Portion)	(210)	615
Natural Gas Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in OCI on Derivatives (Effective Portion)	$ 433	$ 48