Derivative Instruments And Hedging Activities Derivatives and Hedging Instruments Gains Losses due to Settlements Hedge Ineffectiveness (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Trading Activity, Gains and Losses, Net [Line Items]
Change in fair value	$ 3,337	$ (11,921)
Sales and other revenues	3,080,483	2,018,724
(Gain) loss reclassified to earnings due to settlements	374	11,056
Amortization of discontinued hedges reclassified to earnings	270	270
Operating expenses	307,117	252,583
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	3,981	(595)
Gain (Loss) Recognized in Earnings due to Settlements	(644)	(11,326)
Gain (Loss) Attributable to Hedge Ineffectiveness Recognized in Earnings	0	0
Operating Expense [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Attributable to Hedge Ineffectiveness Recognized in Earnings	0	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	3,950	(4,756)
Cost of Goods Sold	(299)	0
Operating expenses	$ (4,295)	$ (6,570)

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
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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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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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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 gain (loss) from the ineffectiveness of the hedge.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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The amount of net gain (loss) reclassified into earnings in the period when cash flow hedge is discontinued because it is probable that the original forecasted transactions will not occur by the end of the original period or an additional two month time period.

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Excludes Selling, General and Administrative Expense.

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Revenue related to the downstream oil and gas activities, including the refining of crude oil, as well as the marketing and distribution of crude oil, refined petroleum products, and natural gas.

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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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