ACQUISITIONS AND DIVESTITURES - 2018 Activity (Details) $ / shares in Units, shares in Millions, $ in Millions							1 Months Ended	12 Months Ended
	Jul. 01, 2019 USD ($)	May 23, 2019 USD ($)	Nov. 29, 2018 USD ($) a fraction_per_share location $ / shares shares	Oct. 31, 2018 USD ($) a shares	Aug. 15, 2018 USD ($) a	Jan. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Proceeds from divestiture of certain conventional and non-core assets	$ 285	$ 37
Estimated total net horizontal permian locations | location			7,200
Ajax Acquisition
Business Acquisition [Line Items]
Area of land (in acres) | a				25,493
Payment to acquire businesses				$ 900
Number of shares to be issued in acquisition (in Shares) | shares				2.6
2018 Drop-Down Transaction
Business Acquisition [Line Items]
Percentage of mineral acres operated					80.00%
Proceeds from divestiture of certain conventional and non-core assets					$ 175
ExL Acquisition
Business Acquisition [Line Items]
Area of land (in acres) | a				3,646
Payment to acquire businesses				$ 313
Energen
Business Acquisition [Line Items]
Common stock, per share conversion basis | fraction_per_share			0.6442
Number of shares to be issued in acquisition (in Shares) | shares			62.8
Business combination, consideration transferred			$ 7,100
Business acquisition, share price | $ / shares			$ 112.00
Business combination, pro forma information, revenue of acquiree since acquisition date, actual							$ 102
Business combination, pro forma information, direct operating expenses since acquisition date, actual							$ 17
Minimum
Business Acquisition [Line Items]
Combined tier one acres | a			273,000
Midland and Delaware Basins
Business Acquisition [Line Items]
Area of land (in acres) | a			394,000
Viper Energy Partners LP | 2018 Drop-Down Transaction
Business Acquisition [Line Items]
Mineral properties acquired, gross acres | a					32,424
Mineral properties acquired net royalty acres | a					1,696
Diamondback Energy, Inc.
Business Acquisition [Line Items]
Acquisition related costs incurred								$ 37
Energen
Business Acquisition [Line Items]
Acquisition related costs incurred								$ 59
Office Building | Midland, TX
Business Acquisition [Line Items]
Payments to acquire property, plant, and equipment						$ 110