Derivative Financial Instruments (Derivative Gains (Losses) Included In Accumulated Other Comprehensive Loss AOCL) (Details) (USD $) In Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Derivative Financial Instruments [Abstract]
Beginning balance	$ 7,856	$ 3,407	$ 3,325	$ 1,743
Net gain (loss) on commodity hedges	6,539	(179)	11,152	(468)
Reclassification of net gain on interest rate cash flow hedges to interest expense	(41)	(41)	(123)	(123)
Reclassification of net loss (gain) on commodity hedges to product sales revenues	(1,493)	(1,068)	(1,493)	967
Ending balance	$ 12,861	$ 2,119	$ 12,861	$ 2,119

Net of tax effect change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges after taxes. A cash flow hedge is a hedge of the exposure to variability in the cash flows of a recognized asset or liability or a forecasted transaction that is attributable to a particular risk. The change includes an entity's share of an equity investee's increase or decrease in deferred hedging gains or losses. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

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+ Details

- Definition

Net of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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+ Details