SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 520,721	$ 221,825	$ 1,299,744	$ 593,529
Lease bonus - mineral acreage	0	0	0	4,062
Realized (loss) gain on derivatives	(57,419)	(5,406)	(125,943)	49,571
Unrealized gain (loss) on derivatives	9,049	(13,033)	(77,178)	(9,271)
Total revenues	472,351	203,386	1,096,623	637,891
Oil revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	325,560	150,620	853,953	414,379
Natural gas revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	135,905	38,484	335,819	91,406
Third-party midstream services revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	20,486	19,363	55,774	49,861
Sales of purchased natural gas
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 38,770	$ 13,358	$ 54,198	$ 37,883