SUPPLEMENTAL OIL AND GAS DISCLOSURES (Unaudited) - Revenue and Direct Cost Information Relating to Company's Oil and Gas Exploration and Production 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]
Oil and gas production revenues	$ 7,348	$ 5,887	$ 5,367
Asset retirement obligation accretion	108	130	156
Lease operating expenses	1,439	1,384	1,494
Gathering, transmission, and processing	348	195	200
Oil and Gas, Exploration and Production
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	7,348	5,887	5,367
Depreciation, depletion, and amortization	2,265	2,136	2,460
Asset retirement obligation accretion	107	130	156
Lease operating expenses	1,439	1,384	1,494
Gathering, transmission, and processing	371	194	200
Exploration expenses	503	549	473
Impairments related to oil and gas properties	338		427
Production taxes	203	150	120
Income tax	848	601	148
Operating costs	6,074	5,144	5,478
Results of operation	1,274	743	(111)
Oil and Gas, Exploration and Production | United States
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	3,279	2,271	1,997
Depreciation, depletion, and amortization	1,206	924	1,055
Asset retirement obligation accretion	32	31	34
Lease operating expenses	670	584	553
Gathering, transmission, and processing	282	86	80
Exploration expenses	219	363	285
Impairments related to oil and gas properties	265		61
Production taxes	203	153	135
Income tax	87	45	(72)
Operating costs	2,964	2,186	2,131
Results of operation	315	85	(134)
Oil and Gas, Exploration and Production | Canada
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	0	231	343
Depreciation, depletion, and amortization	0	72	174
Asset retirement obligation accretion	0	27	47
Lease operating expenses	0	103	181
Gathering, transmission, and processing	0	34	68
Exploration expenses	0	11	88
Impairments related to oil and gas properties	0		366
Production taxes	0	11	18
Income tax	0	(7)	(162)
Operating costs	0	251	780
Results of operation	0	(20)	(437)
Oil and Gas, Exploration and Production | Egypt
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	2,748	2,307	2,057
Depreciation, depletion, and amortization	688	707	733
Asset retirement obligation accretion	0	0	0
Lease operating expenses	428	362	446
Gathering, transmission, and processing	47	44	44
Exploration expenses	88	62	48
Impairments related to oil and gas properties	63		0
Production taxes	0	0	0
Income tax	645	509	354
Operating costs	1,959	1,684	1,625
Results of operation	789	623	432
Oil and Gas, Exploration and Production | North Sea
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	1,321	1,078	970
Depreciation, depletion, and amortization	371	433	498
Asset retirement obligation accretion	75	72	75
Lease operating expenses	341	335	314
Gathering, transmission, and processing	42	30	8
Exploration expenses	192	86	37
Impairments related to oil and gas properties	10		0
Production taxes	0	(14)	(33)
Income tax	116	54	28
Operating costs	1,147	996	927
Results of operation	174	82	43
Oil and Gas, Exploration and Production | Other International
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	0	0	0
Depreciation, depletion, and amortization	0	0	0
Asset retirement obligation accretion	0	0	0
Lease operating expenses	0	0	0
Gathering, transmission, and processing	0	0	0
Exploration expenses	4	27	15
Impairments related to oil and gas properties	0		0
Production taxes	0	0	0
Income tax	0	0	0
Operating costs	4	27	15
Results of operation	$ (4)	$ (27)	$ (15)