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Derivative Instruments Derivative Instruments - Gain (Loss) on Derivative Instruments (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Derivative [Line Items] |  |  |
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net | $ 83,671 | $ 121,148 | $ (18,189)
Gas sales |  |  |
Derivative [Line Items] |  |  |
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net | 72,412 | 115,324 | (12,484)
Oil and condensate sales |  |  |
Derivative [Line Items] |  |  |
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net | 10,149 | 5,824 | (5,705)
Natural gas liquids sales |  |  |
Derivative [Line Items] |  |  |
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net | $ 1,110 | $ 0 | $ 0

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- Definition Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986 + Details
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