COMMODITY DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments (Details) bbl in Thousands	6 Months Ended
Jun. 30, 2018 USD ($) $ / bbl bbl
Derivative [Line Items]
Fair Value	$ (46,614)
Swap
Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) \| $ / bbl	62.29
Remaining Volume (Barrels) \| bbl	60
Fair Value	$ 320,000
Swap
Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) \| $ / bbl	86.32
Remaining Volume (Barrels) \| bbl	60
Fair Value	$ (229,656)
Futures
Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) \| $ / bbl	90.98
Remaining Volume (Barrels) \| bbl	75
Fair Value	$ (136,958)

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

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