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Derivative Financial Instruments Gains and Losses (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015
Gain and loss from derivative cash settlements and changes in fair value of derivative contracts |  |  |  |  |
Derivative settlement gain (loss) |  | $ (57,496) | $ (113,695) | $ (306,234) | $ (387,719)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net |  | (28,037) | (212,253) | 121,086 | (285,491)
NYMEX Oil Contracts [Member] |  |  |  |  |
Gain and loss from derivative cash settlements and changes in fair value of derivative contracts |  |  |  |  |
Derivative settlement gain (loss) |  | (49,241) | (90,493) | (221,397) | (270,622)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net |  | (733) | (131,728) | 49,608 | (138,839)
Gas Contracts [Member] |  |  |  |  |
Gain and loss from derivative cash settlements and changes in fair value of derivative contracts |  |  |  |  |
Gain on Early Settlement of Derivatives |  |  |  |  | (15,300)
Derivative settlement gain (loss) | [1] | (10,096) | (19,167) | (82,588) | (92,279)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net |  | (14,006) | (66,538) | 24,460 | (142,807)
NGL Contracts [Member] |  |  |  |  |
Gain and loss from derivative cash settlements and changes in fair value of derivative contracts |  |  |  |  |
Derivative settlement gain (loss) |  | 1,841 | (4,035) | (2,249) | (24,818)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net |  | $ (13,298) | $ (13,987) | $ 47,018 | $ (3,845)
[1] | Natural gas derivative settlements for the nine months ended September 30, 2015, include a $15.3 million gain on the early settlement of future contracts as a result of divesting the Company’s Mid-Continent assets during the second quarter of 2015.

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- Definition Gain on Early Settlement of Derivatives + References No definition available. + Details
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- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 + Details
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