ACQUISITIONS (Details) $ in Millions		9 Months Ended
	Jan. 01, 2019 USD ($) SWD well PWD_well system pit	Sep. 30, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Contribution of property		$ 456.1
Ajax | Water Wells
Property, Plant and Equipment [Line Items]
Number of oil and gas properties | well	17
Ajax | Gathering system
Property, Plant and Equipment [Line Items]
Number of oil and gas properties | system	1
Ajax | Hydraulic Fracturing Pits
Property, Plant and Equipment [Line Items]
Number of oil and gas properties | pit	5
Ajax | Fresh Water Transportation System
Property, Plant and Equipment [Line Items]
Number of oil and gas properties | system	1
Ajax | Ajax Contribution
Property, Plant and Equipment [Line Items]
Contribution of property	$ 21.5
Ajax | Produced Water Disposal
Property, Plant and Equipment [Line Items]
Number of oil and gas properties | SWD	4
Energen
Property, Plant and Equipment [Line Items]
Asset retirement obligations, associated with assets contribution	$ 3.0
Energen | Produced Water Disposal
Property, Plant and Equipment [Line Items]
Number of oil and gas properties | PWD_well	56
Energen | Energen Contribution
Property, Plant and Equipment [Line Items]
Contribution of property	$ 279.0