SUPPLEMENTAL INFORMATION ON OIL AND NATURAL GAS OPERATIONS (Unaudited) - Narrative (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($) Boe	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) Boe	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) Boe MBoe well SWD	Dec. 31, 2018 USD ($) Boe MBoe SWD	Dec. 31, 2017 USD ($) Boe
Oil and Gas, Delivery Commitment [Line Items]
Provision for income taxes | $	$ (124)	$ 102	$ 102	$ (33)	$ 85	$ 43	$ (7)	$ 47	$ 47	$ 168	$ (20)
Revised income tax expense | $									$ (89)	$ (241)	$ 20
Extensions and discoveries (in MBOE)									376,287,000	202,089,000	138,977,000
Oil and gas development well drilled net productive									283	135	102
Proved undeveloped reserves number of wells added									291	138	87
Percentage of extension volumes attributable to subsidiary									5.00%	10.00%	8.00%
Revision of previous estimate as result of positive technical and performance revisions (in MBOE)										14,218,000	8,308,000
Revisions due to higher pricing (in MBOE) | MBoe										6,032
Revisions from PUD reclassifications due to timing									(117,898,000)	(4,815,000)	2,550,000
Increase due to purchase of reserves									21,092,000	486,992
Purchase of working interest in Reserves									10,939,000	477,686
Proved undeveloped reserves (energy)	367,859,000				345,928,000				367,859,000	345,928,000
Proved undeveloped reserves, increase (energy)									21,931,000
Extensions and discoveries, working interest (in MBOE) | MBoe									213,909
Number of horizontal wells developed, working interest gross | well									291
Number of horizontal wells developed, working interest | well									262
Proved undeveloped reserves extensions and discoveries mineral interest | MBoe									7,591
Number of horizontal wells developed, mineral interest | well									97
Undeveloped reserves transferred to developed									120,920,000
Number of horizontal wells developed working interest gross | well									135
Number of horizontal wells developed working interest net | well									119
Number of horizontal wells developed mineral interest gross | well									79
Number of horizontal wells developed working and mineral interest | well									75
Revisions									(77,519,000)
Revisions from PUD reclassifications due to refinement									67,114,000
Revisions from PUD reclassifications due to lower benchmark commodity prices									10,405,000
Proved undeveloped reserves, planned development period									5 years
Capital expenditures towards development of proved undeveloped reserves | $									$ 956	$ 493	$ 145
Delaware Basin
Oil and Gas, Delivery Commitment [Line Items]
Percentage of total purchase volumes											87.00%
Number of horizontal wells developed working interest | well									64
Viper Energy Partners LP
Oil and Gas, Delivery Commitment [Line Items]
Royalty purchases									10,153,000	9,306
Percentage of total purchase volumes											10.00%