Derivative Financial Instruments (Schedule Of Derivative Instruments) (Details)	6 Months Ended
	Jun. 30, 2012
Qualifies For Hedge Accounting Treatment [Member] | NYMEX - Cash Flow Hedges [Member]
Derivative [Line Items]
Hedge Type	Cash Flow Hedge
Hedge Purpose	To hedge the variability in cash flowsrelated to a forecasted transaction.
Accounting Treatment	The effective portion of changes in the value of thehedge are recorded to accumulated othercomprehensive income/loss and reclassified toearnings when the forecasted transaction occurs. Anyineffectiveness is recognized currently in earnings.
Qualifies For Hedge Accounting Treatment [Member] | NYMEX - Fair Value Hedges [Member]
Derivative [Line Items]
Hedge Type	Fair Value Hedge
Hedge Purpose	To hedge against changes in the fairvalue of a recognized asset or liability.
Accounting Treatment	The effective portion of changes in the value of thehedge are recorded as adjustments to the asset orliability being hedged. Any ineffectiveness isrecognized currently in earnings.
Does Not Qualify For Hedge Accounting Treatment [Member] | NYMEX - Economic Hedges [Member]
Derivative [Line Items]
Hedge Type	Economic Hedge
Hedge Purpose	To effectively serve as either a fairvalue or a cash flow hedge; however,the derivative agreement does notqualify for hedge accounting treatmentor is not designated as a hedge inaccordance with Accounting StandardsCodification ("ASC") 815, Derivativesand Hedging.
Accounting Treatment	Changes in the value of these agreements arerecognized currently in earnings.