SUPPLEMENTAL OIL AND GAS INFORMATION (UNAUDITED) - Average Sales Prices (Details)	12 Months Ended
	Dec. 31, 2019 $ / bbl $ / Mcf	Dec. 31, 2018 $ / bbl $ / Mcf	Dec. 31, 2017 $ / bbl $ / Mcf
Natural Gas
Reserve Quantities [Line Items]
Average sale price (in dollars per volume unit) | $ / Mcf	2.12	4.50	3.34
Oil
Reserve Quantities [Line Items]
Average sale price (in dollars per volume unit) | $ / bbl	50.53	61.23	45.90