DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Instruments (Details) - Natural Gas MMBTU in Thousands	12 Months Ended
	Dec. 31, 2020 $ / MMBTU MMBTU
Basis Swap Purchased | April to December 2021 | NYMEX Henry Hub/IF Waha
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	37,580
Weighted average price differential | $ / MMBTU	(0.43)
Basis Swap Purchased | January to December 2022 | NYMEX Henry Hub/IF Waha
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	43,800
Weighted average price differential | $ / MMBTU	(0.45)
Basis Swap Sold | April to December 2021 | NYMEX Henry Hub/IF HSC
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	37,580
Weighted average price differential | $ / MMBTU	(0.07)
Basis Swap Sold | January to December 2022 | NYMEX Henry Hub/IF HSC
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	43,800
Weighted average price differential | $ / MMBTU	(0.08)