SUPPLEMENTAL OIL AND GAS DISCLOSURES (Unaudited) - Costs Incurred in Oil and Gas Property Acquisitions, Exploration and Development Activities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	$ 6	$ 7	$ 45
Unproved	127	181	170
Exploration	940	891	470
Development	2,381	1,807	950
Costs incurred	3,454	2,886	1,635
Capitalized interest	36	44	48
Asset retirement costs	31	70	(192)
United States
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	0	3	0
Unproved	111	136	110
Exploration	640	602	278
Development	1,791	1,118	420
Costs incurred	2,542	1,859	808
Capitalized interest	23	23	21
Asset retirement costs	93	15	(51)
Canada
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	0	0	1
Unproved	0	5	7
Exploration	0	11	23
Development	0	52	27
Costs incurred	0	68	58
Capitalized interest	0	2	6
Asset retirement costs	0	0	(13)
Egypt
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Proved	6	4	6
Unproved	16	40	49
Exploration	175	122	67
Development	457	387	353
Costs incurred	654	553	475
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	38
Unproved	0	0	4
Exploration	113	131	84
Development	133	250	150
Costs incurred	246	381	276
Capitalized interest	11	17	21
Asset retirement costs	(62)	55	(128)
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	12	25	18
Development	0	0	0
Costs incurred	12	25	18
Capitalized interest	2	2	0
Asset retirement costs	$ 0	$ 0	$ 0