Derivatives (Schedule Of Fair Value Of Derivative Assets And Liabilities) (Details) (Other Current Assets [Member], Total Commodity Derivatives [Member], Not Designated As Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Other Current Assets [Member] | Total Commodity Derivatives [Member] | Not Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 1,053	$ 758
Derivative Asset, Fair Value, Gross Liability	(851)	(758)
Derivative Liability, Fair Value, Gross Liability	851	3,357
Derivative Liability, Fair Value, Gross Asset	851	3,357
Derivative Liability	0	0
Derivative Asset	$ 202	$ 0