BUSINESS SEGMENT INFORMATION (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) Segment	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of reporting segments | Segment			3
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 1,598,000,000	$ 1,936,000,000	$ 3,252,000,000	$ 3,669,000,000
Lease operating expenses	389,000,000	356,000,000	754,000,000	705,000,000
Gathering, processing, and transmission	76,000,000	82,000,000	164,000,000	168,000,000
Taxes other than income	46,000,000	49,000,000	97,000,000	104,000,000
Exploration	95,000,000	76,000,000	164,000,000	152,000,000
Depreciation, depletion, and amortization	602,000,000	608,000,000	1,248,000,000	1,161,000,000
Asset retirement obligation accretion	26,000,000	27,000,000	53,000,000	54,000,000
Impairments	240,000,000	0	240,000,000	0
Operating expenses	1,474,000,000	1,198,000,000	2,720,000,000	2,344,000,000
Operating Income (Loss)	124,000,000	738,000,000	532,000,000	1,325,000,000
Other Income (Expense):
Gain on divestitures	17,000,000	2,000,000	20,000,000	9,000,000
Derivative instrument losses, net	(8,000,000)	(25,000,000)	(38,000,000)	(23,000,000)
Other	(4,000,000)	16,000,000	4,000,000	21,000,000
General and administrative	(102,000,000)	(117,000,000)	(225,000,000)	(231,000,000)
Transaction, reorganization, and separation	(6,000,000)	(12,000,000)	(10,000,000)	(12,000,000)
Financing costs, net	(173,000,000)	(94,000,000)	(270,000,000)	(193,000,000)
NET INCOME (LOSS) BEFORE INCOME TAXES	(152,000,000)	508,000,000	13,000,000	896,000,000
Revenues from non-customers	120,000,000	181,000,000	240,000,000	336,000,000
Total Assets	21,806,000,000	21,910,000,000	21,806,000,000	21,910,000,000	$ 21,582,000,000
Impairments	240,000,000	0	240,000,000	0
Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	596,000,000	742,000,000	1,195,000,000	1,402,000,000
Lease operating expenses	132,000,000	106,000,000	250,000,000	204,000,000
Gathering, processing, and transmission	10,000,000	11,000,000	22,000,000	23,000,000
Taxes other than income	0	0	0	0
Exploration	30,000,000	32,000,000	62,000,000	60,000,000
Depreciation, depletion, and amortization	174,000,000	192,000,000	361,000,000	378,000,000
Asset retirement obligation accretion	0	0	0	0
Impairments	0	0	0	0
Operating expenses	346,000,000	341,000,000	695,000,000	665,000,000
Operating Income (Loss)	250,000,000	401,000,000	500,000,000	737,000,000
Other Income (Expense):
Total Assets	4,035,000,000	4,471,000,000	4,035,000,000	4,471,000,000
Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	360,000,000	352,000,000	698,000,000	651,000,000
Lease operating expenses	92,000,000	78,000,000	164,000,000	172,000,000
Gathering, processing, and transmission	11,000,000	10,000,000	23,000,000	20,000,000
Taxes other than income	0	0	0	0
Exploration	1,000,000	3,000,000	2,000,000	17,000,000
Depreciation, depletion, and amortization	99,000,000	96,000,000	198,000,000	191,000,000
Asset retirement obligation accretion	18,000,000	19,000,000	37,000,000	37,000,000
Impairments	0	0	0	0
Operating expenses	221,000,000	206,000,000	424,000,000	437,000,000
Operating Income (Loss)	139,000,000	146,000,000	274,000,000	214,000,000
Other Income (Expense):
Total Assets	2,568,000,000	3,148,000,000	2,568,000,000	3,148,000,000
Impairments	2,000,000		4,000,000	37,000,000
Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	642,000,000	842,000,000	1,359,000,000	1,616,000,000
Lease operating expenses	166,000,000	172,000,000	342,000,000	329,000,000
Gathering, processing, and transmission	64,000,000	62,000,000	145,000,000	127,000,000
Taxes other than income	42,000,000	47,000,000	91,000,000	99,000,000
Exploration	59,000,000	40,000,000	92,000,000	73,000,000
Depreciation, depletion, and amortization	320,000,000	315,000,000	673,000,000	584,000,000
Asset retirement obligation accretion	8,000,000	8,000,000	15,000,000	16,000,000
Impairments	240,000,000	0	240,000,000	0
Operating expenses	899,000,000	644,000,000	1,598,000,000	1,228,000,000
Operating Income (Loss)	(257,000,000)	198,000,000	(239,000,000)	388,000,000
Other Income (Expense):
Total Assets	12,710,000,000	13,311,000,000	12,710,000,000	13,311,000,000
Impairments	277,000,000	21,000,000	298,000,000
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	14,000,000	11,000,000	30,000,000	22,000,000
Taxes other than income	4,000,000	2,000,000	6,000,000	5,000,000
Exploration	0	0	0	0
Depreciation, depletion, and amortization	9,000,000	5,000,000	16,000,000	8,000,000
Asset retirement obligation accretion	0	0	1,000,000	1,000,000
Impairments	0	0	0	0
Operating expenses	27,000,000	18,000,000	53,000,000	36,000,000
Operating Income (Loss)	(3,000,000)	(6,000,000)	5,000,000	(12,000,000)
Other Income (Expense):
Total Assets	2,434,000,000	939,000,000	2,434,000,000	939,000,000
Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	(24,000,000)	(12,000,000)	(58,000,000)	(24,000,000)
Lease operating expenses	(1,000,000)	0	(2,000,000)	0
Gathering, processing, and transmission	(23,000,000)	(12,000,000)	(56,000,000)	(24,000,000)
Taxes other than income	0	0	0	0
Exploration	5,000,000	1,000,000	8,000,000	2,000,000
Depreciation, depletion, and amortization	0	0	0	0
Asset retirement obligation accretion	0	0	0	0
Impairments	0	0	0	0
Operating expenses	(19,000,000)	(11,000,000)	(50,000,000)	(22,000,000)
Operating Income (Loss)	(5,000,000)	(1,000,000)	(8,000,000)	(2,000,000)
Other Income (Expense):
Total Assets	59,000,000	41,000,000	59,000,000	41,000,000
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	24,000,000	12,000,000	58,000,000	24,000,000
Oil and Gas, Purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	18,000,000	98,000,000	42,000,000	202,000,000
Gathering, processing, and transmission	15,000,000	95,000,000	37,000,000	199,000,000
Oil
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,397,000,000	1,576,000,000	2,707,000,000	2,969,000,000
Other Income (Expense):
Revenues from non-customers	111,000,000	165,000,000	218,000,000	304,000,000
Oil | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	523,000,000	649,000,000	1,037,000,000	1,218,000,000
Oil | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	337,000,000	320,000,000	637,000,000	591,000,000
Oil | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	537,000,000	607,000,000	1,033,000,000	1,160,000,000
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	118,000,000	212,000,000	354,000,000	434,000,000
Other Income (Expense):
Revenues from non-customers	9,000,000	15,000,000	21,000,000	30,000,000
Natural Gas | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	70,000,000	89,000,000	151,000,000	177,000,000
Natural Gas | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	18,000,000	27,000,000	50,000,000	51,000,000
Natural Gas | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	30,000,000	96,000,000	153,000,000	206,000,000
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	83,000,000	148,000,000	191,000,000	266,000,000
Other Income (Expense):
Revenues from non-customers	0	1,000,000	1,000,000	2,000,000
Natural Gas liquids | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	3,000,000	4,000,000	7,000,000	7,000,000
Natural Gas liquids | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	5,000,000	5,000,000	11,000,000	9,000,000
Natural Gas liquids | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	75,000,000	139,000,000	173,000,000	250,000,000
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