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Derivative Financial Instruments Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	$ (24,722)	$ 40,718	$ (23,843)	$ 101,911
Net derivative (gain) loss	(100,889)	178,026	(3,463)	249,304
Oil Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	2,246	16,798	14,304	61,976
Net derivative (gain) loss	(83,984)	110,413	67,261	146,781
Gas Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	(12,210)	802	(13,744)	(4,851)
Net derivative (gain) loss	(4,228)	4,309	(36,337)	21,299
NGL Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	(14,758)	23,118	(24,403)	44,786
Net derivative (gain) loss	$ (12,677)	$ 63,304	$ (34,387)	$ 81,224

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- Definition

Realized gain or loss recognized in earnings from the settlement of derivative instruments not designated as hedges.

+ References

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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

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