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	Mar. 31, 2014	Dec. 31, 2013
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	$ 699	$ 615
Derivative Asset, Fair Value, Gross Liability	(699)	(615)
Derivative Liability, Fair Value, Gross Liability	700	4,527
Derivative Liability, Fair Value, Gross Asset	700	4,527
Derivative Liability	0	0
Derivative Asset	$ 0	$ 0