Derivative Instruments And Hedging Activities Derivatives and Hedging Instruments Gains Losses due to Settlements Hedge Ineffectiveness (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Trading Activity, Gains and Losses, Net [Line Items]
Derivative Instruments, change in fair value	$ (9,550)	$ 5,312	$ 112,499	$ 40,644
Gain (Loss) on Fair Value Hedges Recognized in Earnings	14,130	21,737	32,547	766
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	(4,790)	1,246	(5,596)	2,873
Sales and other revenues [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(6,202)	(10,138)	(80,475)	(25,454)
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	1,498	1,949	1,498	2,143
Cost of Sales [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	20,776	32,874	111,217	28,271
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	(6,189)	(962)	(6,189)	730
Operating Expense [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(444)	(999)	1,805	(2,051)
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	(99)	259	(905)	0
Commodity Contract [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	4,580	27,049	145,046	41,410
(Gain) Loss Reclassified to Earnings Due to Settlements	(14,400)	(22,007)	(33,357)	(1,396)
Amortization Of Discontinued Hedges Reclassified to Earnings	$ 270	$ 270	$ 810	$ 630