SUPPLEMENTAL OIL AND GAS DISCLOSURES (Unaudited) - Costs Incurred in Oil and Gas Property Acquisitions, Exploration and Development Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	$ 8	$ 6	$ 7
Unproved	57	127	181
Exploration	468	940	891
Development	1,996	2,381	1,807
Costs incurred	2,529	3,454	2,886
Capitalized interest	32	36	44
Asset retirement costs	(97)	31	70
United States
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	3	0	3
Unproved	47	111	136
Exploration	162	640	602
Development	1,500	1,791	1,118
Costs incurred	1,712	2,542	1,859
Capitalized interest	23	23	23
Asset retirement costs	14	93	15
Canada
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	0	0	0
Unproved	0	0	5
Exploration	0	0	11
Development	0	0	52
Costs incurred	0	0	68
Capitalized interest	0	0	2
Asset retirement costs	0	0	0
Egypt
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	5	6	4
Unproved	10	16	40
Exploration	139	175	122
Development	374	457	387
Costs incurred	528	654	553
Capitalized interest	0	0	0
Asset retirement costs	0	0	0
North Sea
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	0	0	0
Unproved	0	0	0
Exploration	62	113	131
Development	119	133	250
Costs incurred	181	246	381
Capitalized interest	5	11	17
Asset retirement costs	(111)	(62)	55
Other International
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	0	0	0
Unproved	0	0	0
Exploration	105	12	25
Development	3	0	0
Costs incurred	108	12	25
Capitalized interest	4	2	2
Asset retirement costs	$ 0	$ 0	$ 0