SUPPLEMENTAL DISCLOSURES - Summary of Current Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	$ 175,634	$ 119,158
Accrued evaluated and unproved and unevaluated property costs
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	77,708	44,012
Accrued midstream properties costs
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	18,625	12,776
Accrued lease operating expenses
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	33,055	24,276
Accrued interest on debt
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	2,929	18,315
Accrued asset retirement obligations
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	231	623
Accrued partners’ share of joint interest charges
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	7,986	7,407
Accrued payable related to purchased natural gas
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	11,361	418
Other
Condensed Balance Sheet Statements, Captions [Line Items]
Total accrued liabilities	$ 23,739	$ 11,331