CAPITALIZED EXPLORATORY WELL COSTS - Capitalized Exploratory Well Costs Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Capitalized Exploratory Well Costs that are Pending Determination of Proved Reserves [Roll Forward]
Capitalized exploratory well costs, Beginning Balance	$ 159	$ 350	$ 264
Additions pending determination of proved reserves	286	602	477
Divestitures and other	(100)	(82)	(3)
Reclassifications to proved properties	(179)	(647)	(373)
Charged to exploration expense	(25)	(64)	(15)
Capitalized exploratory well costs, Ending Balance	$ 141	$ 159	$ 350