FAIR VALUE MEASUREMENTS (Details) - USD ($) shares in Millions	1 Months Ended	2 Months Ended	3 Months Ended	5 Months Ended	6 Months Ended	12 Months Ended
	Jan. 31, 2019	May 31, 2018	Jun. 30, 2019	May 31, 2018	Jun. 30, 2019	Dec. 31, 2018
Fair Value Measurements [Line Items]
Impairment of oil and gas properties			$ 73,151,000		$ 99,279,000
Magnolia Oil Gas Parent LLC And Magnolia Oil Gas Corporation [Member]
Fair Value Measurements [Line Items]
Common stock of Mangolia sold	4.2
Proceeds from sale of available-for-sale securities, equity	$ 51,700,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Magnolia Oil Gas Parent LLC And Magnolia Oil Gas Corporation [Member]
Fair Value Measurements [Line Items]
Common stock of Magnolia traded in public exchange						4.2
Nonrecurring basis | Proved Property Barnett Shale
Fair Value Measurements [Line Items]
Impairment of oil and gas properties			72,100,000		72,100,000
Nonrecurring basis | Proved Property San Juan Basin and Mid-continent Area
Fair Value Measurements [Line Items]
Impairment of oil and gas properties			$ 1,100,000		$ 27,200,000
Predecessor
Fair Value Measurements [Line Items]
Impairment of oil and gas properties				$ 3,000
Predecessor | Nonrecurring basis | Proved Properties [Member]
Fair Value Measurements [Line Items]
Impairment of oil and gas properties		$ 0		$ 0