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Derivative Financial Instruments Gains and Losses (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Derivative Instruments, (Gain) Loss [Line Items] |  |  |
Derivative settlement (gain) loss | $ (39,222) | $ 135,803 | $ (21,234)
Net derivative (gain) loss | 97,539 | (161,832) | 26,414
Oil Contracts [Member] |  |  |
Derivative Instruments, (Gain) Loss [Line Items] |  |  |
Derivative settlement (gain) loss | 19,685 | 68,860 | 31,176
Net derivative (gain) loss | 172,055 | (192,002) | 71,502
Gas Contracts [Member] |  |  |
Derivative Instruments, (Gain) Loss [Line Items] |  |  |
Derivative settlement (gain) loss | (23,008) | 13,029 | (87,857)
Net derivative (gain) loss | (41,205) | 35,411 | (76,315)
NGL Contracts [Member] |  |  |
Derivative Instruments, (Gain) Loss [Line Items] |  |  |
Derivative settlement (gain) loss | (35,899) | 53,914 | 35,447
Net derivative (gain) loss | $ (33,311) | $ (5,241) | $ 31,227

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- Definition Realized gain or loss recognized in earnings from the settlement of derivative instruments not designated as hedges. + References No definition available. + Details
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- Definition Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
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