DERIVATIVE COMMODITY INSTRUMENTS - Reclassification (Details)	12 Months Ended
	Dec. 31, 2017 MBbls Bcf MMgals $ / bbl $ / Mcf $ / gal
NYMEX Three-Way Collars | Oil | 2018
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | MBbls	13,500
NYMEX Three-Way Collars | Oil | 2019
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | MBbls	4,680
WTI/WTI Basis Swaps | Oil | 2018
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | MBbls	10,800
Average Contract Price (in uadPerbbl, usdPergal and usdPerMcf)	(1.01)
WTI/WTI Basis Swaps | Oil | 2019
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | MBbls	4,680
Average Contract Price (in uadPerbbl, usdPergal and usdPerMcf)	(0.44)
Liquids Swaps | Natural Gas Liquids | 2018
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | MMgals	105.8
Average Contract Price (in uadPerbbl, usdPergal and usdPerMcf) | $ / gal	0.59
Liquids Swaps | Natural Gas Liquids | 2019
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | MMgals	25.2
Average Contract Price (in uadPerbbl, usdPergal and usdPerMcf) | $ / gal	0.66
Basin Specific Swaps - Permian | Natural Gas | 2018
Derivatives, Fair Value [Line Items]
Total Hedged Volumes (in MBbl and Bcf) | Bcf	3.6
Underlying, Derivative (in usdPerMcf) | $ / Mcf	2.56
Short | Ceiling sold price (call) | Oil | 2018
Derivatives, Fair Value [Line Items]
Derivative, Cap Price (in usdPerbbl)	60.04
Short | Ceiling sold price (call) | Oil | 2019
Derivatives, Fair Value [Line Items]
Derivative, Cap Price (in usdPerbbl)	60.84
Short | Floor purchased/sold price (put) | Oil | 2018
Derivatives, Fair Value [Line Items]
Derivative, Floor Price (in usdPerbbl)	35.47
Short | Floor purchased/sold price (put) | Oil | 2019
Derivatives, Fair Value [Line Items]
Derivative, Floor Price (in usdPerbbl)	35.00
Long | Floor purchased/sold price (put) | Oil | 2018
Derivatives, Fair Value [Line Items]
Derivative, Floor Price (in usdPerbbl)	45.47
Long | Floor purchased/sold price (put) | Oil | 2019
Derivatives, Fair Value [Line Items]
Derivative, Floor Price (in usdPerbbl)	45.00