OIL AND NATURAL GAS PROPERTIES - Narrative (Details) $ in Millions		3 Months Ended
	Feb. 28, 2020 USD ($) a	Mar. 31, 2020 USD ($) a	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Purchase and sale agreement, number of undeveloped net acres sold (in acres) | a	1,185
Proceeds from sale of land held-for-investment | $	$ 24.1
Unproved oil and gas property transferred to prove undeveloped | $		$ 1.3	$ 5.8
Depreciation, depletion, amortization and accretion | $		$ 3.3	$ 8.1
Reeves County
Lessee, Lease, Description [Line Items]
Lessee, operating lease, area of real estate property, expired, previously impaired | a		805
Winkler County
Lessee, Lease, Description [Line Items]
Lessee, operating lease, area of real estate property, expired, previously impaired | a		593