COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Feb. 17, 2017	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Delivery Of Natural Gas And Oil Production To Third Parties
Long-term Purchase Commitment [Line Items]
Payment for volume requirement agreement		$ 15.1	$ 11.4	$ 27.7	$ 22.4
Volume requirement commitment		601.8		$ 601.8
Delivery Of Residue Gas Production
Long-term Purchase Commitment [Line Items]
Term of contractual obligation				10 years
Contractual obligation		30.7		$ 30.7
Rustler Breaks and Wolf Asset Area | Corporate Joint Venture | San Mateo Midstream
Long-term Purchase Commitment [Line Items]
Term of contractual obligation	15 years
Rustler Breaks Asset Area | Corporate Joint Venture | San Mateo Midstream
Long-term Purchase Commitment [Line Items]
Term of contractual obligation	15 years
Operational Agreements | San Mateo Midstream
Long-term Purchase Commitment [Line Items]
Contractual obligation		$ 430.0		$ 430.0