SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentrations of Credit Risk (Details) - Sales - Customer Concentration Risk	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
NGL Crude Logistics
Concentration Risk [Line Items]
Percent of oil and natural gas sales	77.00%	82.00%	66.00%
Duke Energy Field Services
Concentration Risk [Line Items]
Percent of oil and natural gas sales	9.00%	6.00%	8.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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