Derivative Instruments And Hedging Activities (Impact Of Non Designated Derivative Instruments On Income Statement) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Gain (Loss) Recognized in Income on Derivatives	$ (381)	$ 1,267	$ (234)	$ 245
Natural Gas Contracts [Member] | Gain On Oil And Gas Derivative Contracts [Member]
Gain (Loss) Recognized in Income on Derivatives		161		2,643
Foreign Exchange Forward [Member] | Other Expense [Member]
Gain (Loss) Recognized in Income on Derivatives	$ (381)	$ 1,106	$ (234)	$ (2,398)