BUSINESS SEGMENT INFORMATION (Detail)	3 Months Ended
	Mar. 31, 2019 USD ($) Segment	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of reporting segments | Segment	3
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 1,654,000,000	$ 1,733,000,000
Lease operating expenses	365,000,000	349,000,000
Gathering, processing, and transmission	88,000,000	86,000,000
Taxes other than income	51,000,000	55,000,000
Exploration	69,000,000	76,000,000
Depreciation, depletion, and amortization	646,000,000	553,000,000
Asset retirement obligation accretion	27,000,000	27,000,000
Operating expenses	1,246,000,000	1,146,000,000
Operating Income (Loss)	408,000,000	587,000,000
Other Income (Expense):
Gain on divestitures	3,000,000	7,000,000
Derivative instrument gains (losses), net	(30,000,000)	2,000,000
Other	8,000,000	5,000,000
General and administrative	(123,000,000)	(114,000,000)
Transaction, reorganization, and separation	(4,000,000)	0
Financing costs, net	(97,000,000)	(99,000,000)
NET INCOME BEFORE INCOME TAXES	165,000,000	388,000,000
Total Assets	21,751,000,000	21,791,000,000	$ 21,582,000,000
Revenue from non-customer	119,000,000	155,000,000
Asset impairments	0	0
Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	599,000,000	660,000,000
Lease operating expenses	118,000,000	98,000,000
Gathering, processing, and transmission	12,000,000	12,000,000
Taxes other than income	0	0
Exploration	32,000,000	28,000,000
Depreciation, depletion, and amortization	188,000,000	186,000,000
Asset retirement obligation accretion	0	0
Operating expenses	350,000,000	324,000,000
Operating Income (Loss)	249,000,000	336,000,000
Other Income (Expense):
Total Assets	4,065,000,000	4,813,000,000
Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	338,000,000	299,000,000
Lease operating expenses	72,000,000	93,000,000
Gathering, processing, and transmission	12,000,000	10,000,000
Taxes other than income	0	0
Exploration	1,000,000	14,000,000
Depreciation, depletion, and amortization	99,000,000	95,000,000
Asset retirement obligation accretion	19,000,000	19,000,000
Operating expenses	203,000,000	231,000,000
Operating Income (Loss)	135,000,000	68,000,000
Other Income (Expense):
Total Assets	2,601,000,000	3,009,000,000
Asset impairments	2,000,000
Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	717,000,000	774,000,000
Lease operating expenses	176,000,000	158,000,000
Gathering, processing, and transmission	81,000,000	65,000,000
Taxes other than income	48,000,000	52,000,000
Exploration	33,000,000	33,000,000
Depreciation, depletion, and amortization	352,000,000	269,000,000
Asset retirement obligation accretion	8,000,000	8,000,000
Operating expenses	698,000,000	585,000,000
Operating Income (Loss)	19,000,000	189,000,000
Other Income (Expense):
Total Assets	13,205,000,000	13,106,000,000
Asset impairments	21,000,000	16,000,000
Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Lease operating expenses	0	0
Gathering, processing, and transmission	16,000,000	11,000,000
Taxes other than income	3,000,000	3,000,000
Exploration	0	0
Depreciation, depletion, and amortization	7,000,000	3,000,000
Asset retirement obligation accretion	0	0
Operating expenses	26,000,000	17,000,000
Operating Income (Loss)	8,000,000	(5,000,000)
Other Income (Expense):
Total Assets	1,825,000,000	821,000,000
Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	(34,000,000)	(12,000,000)
Lease operating expenses	(1,000,000)	0
Gathering, processing, and transmission	(33,000,000)	(12,000,000)
Taxes other than income	0	0
Exploration	3,000,000	1,000,000
Depreciation, depletion, and amortization	0	0
Asset retirement obligation accretion	0	0
Operating expenses	(31,000,000)	(11,000,000)
Operating Income (Loss)	(3,000,000)	(1,000,000)
Other Income (Expense):
Total Assets	55,000,000	42,000,000
Intersegment Eliminations & Other | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Intersegment Eliminations & Other | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Intersegment Eliminations & Other | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Intersegment Eliminations & Other | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	34,000,000	12,000,000
Oil and Gas, Purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	24,000,000	104,000,000
Gathering, processing, and transmission	22,000,000	105,000,000
Oil
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,310,000,000	1,393,000,000
Other Income (Expense):
Revenue from non-customer	107,000,000	139,000,000
Oil | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	514,000,000	569,000,000
Oil | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	300,000,000	271,000,000
Oil | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	496,000,000	553,000,000
Oil | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Oil | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Natural Gas
Segment Reporting Information [Line Items]
Oil and gas production revenues	236,000,000	222,000,000
Other Income (Expense):
Revenue from non-customer	11,000,000	15,000,000
Natural Gas | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	81,000,000	88,000,000
Natural Gas | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	32,000,000	24,000,000
Natural Gas | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	123,000,000	110,000,000
Natural Gas | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Natural Gas | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Natural gas liquids
Segment Reporting Information [Line Items]
Oil and gas production revenues	108,000,000	118,000,000
Other Income (Expense):
Revenue from non-customer	1,000,000	1,000,000
Natural gas liquids | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	4,000,000	3,000,000
Natural gas liquids | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	6,000,000	4,000,000
Natural gas liquids | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	98,000,000	111,000,000
Natural gas liquids | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0	0
Natural gas liquids | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 0	$ 0