SEGMENT INFORMATION - Selected Financial Information for Segments (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues			$ 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)
Expenses			242,165	424,527	628,668	1,100,810
Operating (loss) income			230,186	(221,141)	467,955	(462,919)
Total assets	$ 3,786,230		3,985,493	3,786,230	3,985,493	3,786,230	$ 3,687,280
Capital expenditures			167,542	161,607	428,216	636,161
Depletion, depreciation and amortization			89,061	88,025	255,368	272,082
Full-cost ceiling impairment	251,200	$ 324,000	0	251,163	0	575,164
Corporate
Segment Reporting Information [Line Items]
Lease bonus - mineral acreage						0
Realized (loss) gain on derivatives			0	0	0	0
Unrealized gain (loss) on derivatives			0	0	0	0
Expenses			21,575	12,187	64,298	38,913
Operating (loss) income			(21,575)	(12,187)	(64,298)	(38,913)
Total assets	52,867		95,805	52,867	95,805	52,867
Capital expenditures			220	415	465	1,796
Depletion, depreciation and amortization			600	700	2,000	2,100
Consolidations and Eliminations
Segment Reporting Information [Line Items]
Lease bonus - mineral acreage						0
Realized (loss) gain on derivatives			0	0	0	0
Unrealized gain (loss) on derivatives			0	0	0	0
Expenses			(40,729)	(21,466)	(109,041)	(64,951)
Operating (loss) income			0	0	0	0
Total assets	0		0	0	0	0
Capital expenditures			0	0	0	0
Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Lease bonus - mineral acreage						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)
Expenses			220,535	409,282	576,106	1,054,419
Operating (loss) income			217,362	(231,749)	439,402	(487,110)
Total assets	2,913,409		3,025,668	2,913,409	3,025,668	2,913,409
Capital expenditures			138,374	106,160	381,167	446,604
Depletion, depreciation and amortization			80,600	81,300	230,000	254,200
Capital expenditures attributable to land and seismic acquisition expenditures			17,200	13,700	32,800	63,000
Midstream | Operating Segments
Segment Reporting Information [Line Items]
Lease bonus - mineral acreage						0
Realized (loss) gain on derivatives			0	0	0	0
Unrealized gain (loss) on derivatives			0	0	0	0
Expenses			40,784	24,524	97,305	72,429
Operating (loss) income			34,399	22,795	92,851	63,104
Total assets	$ 819,954		864,020	819,954	864,020	819,954
Capital expenditures			28,948	55,032	46,584	187,761
Depletion, depreciation and amortization			7,800	6,000	23,400	15,800
Net income attributable to non-controlling interest in subsidiaries				(10,000)	(39,200)	(26,800)
Capital expenditures attributable to non-controlling interest			14,200	26,600	22,400	106,000
Operating Income (Loss) | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Net income attributable to non-controlling interest in subsidiaries			(14,400)
Oil and natural gas revenues
Segment Reporting Information [Line Items]
Revenues			461,465	189,104	1,189,772	505,785
Oil and natural gas revenues | Corporate
Segment Reporting Information [Line Items]
Revenues			0	0	0	0
Oil and natural gas revenues | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues			0	0	0	0
Oil and natural gas revenues | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues			460,306	188,492	1,186,086	503,545
Oil and natural gas revenues | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues			1,159	612	3,686	2,240
Midstream services revenues
Segment Reporting Information [Line Items]
Revenues			20,486	19,363	55,774	49,861
Midstream services revenues | Corporate
Segment Reporting Information [Line Items]
Revenues			0	0	0	0
Midstream services revenues | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues			(40,729)	(21,466)	(109,041)	(64,951)
Midstream services revenues | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues			0	0	0	0
Midstream services revenues | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues			61,215	40,829	164,815	114,812
Sales of purchased natural gas
Segment Reporting Information [Line Items]
Revenues			38,770	13,358	54,198	37,883
Sales of purchased natural gas | Corporate
Segment Reporting Information [Line Items]
Revenues			0	0	0	0
Sales of purchased natural gas | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues			0	0	0	0
Sales of purchased natural gas | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues			25,961	7,480	32,543	19,402
Sales of purchased natural gas | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues			$ 12,809	$ 5,878	$ 21,655	$ 18,481