BUSINESS SEGMENT INFORMATION (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) Segment	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of reporting segments | Segment			3
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 1,438	$ 1,976	$ 4,690	$ 5,645
Lease operating expenses	350	382	1,104	1,087
Gathering, processing, and transmission	66	92	230	260
Taxes other than income	44	58	141	162
Exploration	56	99	220	251
Depreciation, depletion, and amortization	711	610	1,959	1,771
Asset retirement obligation accretion	27	27	80	81
Impairments	9	10	249	10
Operating expenses	1,263	1,278	3,983	3,622
Operating Income (Loss)	175	698	707	2,023
Other Income (Expense):
Gain on divestitures	0	1	20	10
Derivative instrument losses, net	(2)	(23)	(40)	(46)
Other	41	29	45	50
General and administrative	(98)	(99)	(323)	(330)
Transaction, reorganization, and separation	(7)	(8)	(17)	(20)
Financing costs, net	(95)	(192)	(365)	(385)
NET INCOME BEFORE INCOME TAXES	14	406	27	1,302
Revenues from non-customers	107	198	347	534
Total Assets	21,405	21,870	21,405	21,870	$ 21,582
Impairments	9	10	249	10
Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	546	759	1,741	2,161
Lease operating expenses	115	112	365	316
Gathering, processing, and transmission	9	12	31	35
Taxes other than income	0	0	0	0
Exploration	27	10	89	70
Depreciation, depletion, and amortization	177	187	538	564
Asset retirement obligation accretion	0	0	0	0
Impairments	0	0	0	0
Operating expenses	328	321	1,023	985
Operating Income (Loss)	218	438	718	1,176
Other Income (Expense):
Total Assets	3,851	4,404	3,851	4,404
Impairments	2		6
Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	250	338	948	989
Lease operating expenses	76	92	240	264
Gathering, processing, and transmission	9	12	32	32
Taxes other than income	0	0	0	0
Exploration	0	2	2	19
Depreciation, depletion, and amortization	71	89	269	281
Asset retirement obligation accretion	19	19	56	56
Impairments	0	10	0	10
Operating expenses	175	224	599	662
Operating Income (Loss)	75	114	349	327
Other Income (Expense):
Total Assets	2,529	3,033	2,529	3,033
Impairments		10		10
Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	642	879	2,001	2,495
Lease operating expenses	159	178	501	507
Gathering, processing, and transmission	69	76	214	204
Taxes other than income	40	57	131	156
Exploration	25	86	117	159
Depreciation, depletion, and amortization	452	329	1,125	913
Asset retirement obligation accretion	8	8	23	24
Impairments	0	0	240	0
Operating expenses	753	734	2,351	1,963
Operating Income (Loss)	(111)	145	(350)	532
Other Income (Expense):
Total Assets	12,288	13,335	12,288	13,335
Impairments	10	39	308	76
Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Lease operating expenses	0	0	0	0
Gathering, processing, and transmission	13	17	43	39
Taxes other than income	4	1	10	6
Exploration	0	0	0	0
Depreciation, depletion, and amortization	11	5	27	13
Asset retirement obligation accretion	0	0	1	1
Impairments	9	0	9	0
Operating expenses	37	23	90	59
Operating Income (Loss)	(3)	2	2	(9)
Other Income (Expense):
Total Assets	2,649	1,054	2,649	1,054
Impairments	9		9
Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	(34)	(25)	(92)	(50)
Lease operating expenses	0	0	(2)	0
Gathering, processing, and transmission	(34)	(25)	(90)	(50)
Taxes other than income	0	0	0	0
Exploration	4	1	12	3
Depreciation, depletion, and amortization	0	0	0	0
Asset retirement obligation accretion	0	0	0	0
Impairments	0	0	0	0
Operating expenses	(30)	(24)	(80)	(47)
Operating Income (Loss)	(4)	(1)	(12)	(3)
Other Income (Expense):
Total Assets	88	44	88	44
Intersegment Eliminations & Other | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Intersegment Eliminations & Other | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Intersegment Eliminations & Other | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Intersegment Eliminations & Other | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	34	25	92	50
Oil and Gas, Purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	30	124	71	326
Gathering, processing, and transmission	23	109	60	308
Oil
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,207	1,555	3,914	4,524
Other Income (Expense):
Revenues from non-customers	98	181	316	485
Oil | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	472	669	1,509	1,887
Oil | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	231	303	868	894
Oil | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	504	583	1,537	1,743
Oil | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Oil | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Natural Gas
Segment Reporting Information [Line Items]
Oil and gas production revenues	136	241	490	675
Other Income (Expense):
Revenues from non-customers	9	16	30	47
Natural Gas | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	72	86	223	263
Natural Gas | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	14	30	64	81
Natural Gas | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	50	125	203	331
Natural Gas | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Natural Gas | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Natural Gas liquids
Segment Reporting Information [Line Items]
Oil and gas production revenues	95	180	286	446
Other Income (Expense):
Revenues from non-customers	0	1	1	2
Natural Gas liquids | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	2	4	9	11
Natural Gas liquids | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	5	5	16	14
Natural Gas liquids | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	88	171	261	421
Natural Gas liquids | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0	0	0
Natural Gas liquids | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 0	$ 0	$ 0	$ 0