Derivatives (Schedule Of Effect On Consolidated Statements Of Operations And Other Comprehensive Income (Loss)) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income, Supply & Logistics Product Costs	$ (17,592,000)		$ 303,000
Amount of Gain (Loss) Recognized in Income, Interest Expense Reclassified from AOCL			(2,112,000)
Interest rate swap loss			(424,000)		(508,000)
Gain on hedged inventory	800,000		1,000,000
Commodity Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income, Supply & Logistics Product Costs	(17,592,000)		303,000
Amount of Gain (Loss) Recognized in Income, Interest Expense Reclassified from AOCL
Interest rate swap loss
Commodity Derivatives [Member] | Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income, Supply & Logistics Product Costs	(173,000)	[1]	307,000	[1]
Amount of Gain (Loss) Recognized in Income, Interest Expense Reclassified from AOCL				[1]
Commodity Derivatives [Member] | Not Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income, Supply & Logistics Product Costs	(17,419,000)		(4,000)
Amount of Gain (Loss) Recognized in Income, Interest Expense Reclassified from AOCL
Interest rate swap loss
Interest Rate Swaps [Member] | Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income, Supply & Logistics Product Costs
Amount of Gain (Loss) Recognized in Income, Interest Expense Reclassified from AOCL			(2,112,000)
Interest rate swap loss			$ (424,000)

[1] Represents the amount of gain (loss) recognized in income for derivatives related to the fair value hedge of inventory. The amount excludes the gain on the hedged inventory under the fair value hedge of $0.8 million and $1 million for the year ended 2011 and 2010, respectively.