Derivative Instruments And Hedging Activities Derivatives and Hedging Instruments Gains Losses due to Settlements Hedge Ineffectiveness (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Trading Activity, Gains and Losses, Net [Line Items]
Change in fair value	$ 1,378	$ (5,138)	$ 4,715	$ (17,059)
Sales and other revenues	3,458,864	2,714,638	6,539,347	4,733,362
(Gain) loss reclassified to earnings due to settlements	(325)	21,910	49	32,966
Amortization of discontinued hedges reclassified to earnings	270	270	540	540
Operating expenses	315,652	251,336	622,769	503,919
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	1,323	17,042	5,304	16,447
Gain (Loss) Recognized in Earnings due to Settlements	55	(22,180)	(589)	(33,506)
Gain (Loss) Attributable to Hedge Ineffectiveness Recognized in Earnings	(18)	0	(18)	0
Operating Expense [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Attributable to Hedge Ineffectiveness Recognized in Earnings	(18)	0	(18)	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] \| Commodity Contract [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Sales and other revenues	4,476	(15,897)	8,426	(20,653)
Cost of Goods Sold			(299)	0
Operating expenses	$ (4,421)	$ (6,283)	$ (8,716)	$ (12,853)

Total costs related to goods produced and sold during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 225
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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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Amount of unrealized gain (loss) related to derivatives designated as cash flow hedging instruments, recorded in results of operations to the extent that the cash flow hedge is determined to be ineffective.

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