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, 2017	Dec. 31, 2016	Dec. 31, 2015
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	$ 5,887	$ 5,367	$ 6,510
Depreciation, depletion, and amortization	2,136	2,460	2,976
Asset retirement obligation accretion	130	156	145
Lease operating expenses	1,400	1,494	1,854
Gathering and transportation	179	200	211
Exploration expenses	549	473	2,771
Impairments related to oil and gas properties		427	7,389
Production taxes	150	120	259
Income tax	601	148	(3,049)
Oil and gas properties production expense	5,145	5,478	12,556
Results of operation	742	(111)	(6,046)
United States
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	2,271	1,997	2,637
Depreciation, depletion, and amortization	924	1,055	1,455
Asset retirement obligation accretion	31	34	28
Lease operating expenses	600	553	739
Gathering and transportation	71	80	68
Exploration expenses	363	285	2,145
Impairments related to oil and gas properties		61	6,154
Production taxes	153	135	178
Income tax	45	(72)	(2,886)
Oil and gas properties production expense	2,187	2,131	7,881
Results of operation	84	(134)	(5,244)
Canada
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	231	343	498
Depreciation, depletion, and amortization	72	174	251
Asset retirement obligation accretion	27	47	43
Lease operating expenses	103	181	244
Gathering and transportation	34	68	89
Exploration expenses	11	88	231
Impairments related to oil and gas properties		366	1,031
Production taxes	11	18	23
Income tax	(7)	(162)	(369)
Oil and gas properties production expense	251	780	1,543
Results of operation	(20)	(437)	(1,045)
Egypt
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	2,307	2,057	2,095
Depreciation, depletion, and amortization	707	733	780
Asset retirement obligation accretion	0	0	0
Lease operating expenses	362	446	522
Gathering and transportation	44	44	45
Exploration expenses	62	48	154
Impairments related to oil and gas properties		0	193
Production taxes	0	0	0
Income tax	509	354	180
Oil and gas properties production expense	1,684	1,625	1,874
Results of operation	623	432	221
North Sea
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Oil and gas production revenues	1,078	970	1,280
Depreciation, depletion, and amortization	433	498	490
Asset retirement obligation accretion	72	75	74
Lease operating expenses	335	314	349
Gathering and transportation	30	8	9
Exploration expenses	86	37	237
Impairments related to oil and gas properties		0	11
Production taxes	(14)	(33)	58
Income tax	54	28	26
Oil and gas properties production expense	996	927	1,254
Results of operation	82	43	26
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 and transportation	0	0	0
Exploration expenses	27	15	4
Impairments related to oil and gas properties		0	0
Production taxes	0	0	0
Income tax	0	0	0
Oil and gas properties production expense	27	15	4
Results of operation	$ (27)	$ (15)	$ (4)