BUSINESS SEGMENT INFORMATION (Details)	3 Months Ended			6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Jun. 30, 2021 USD ($) Segment	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting [Abstract]
Number of operating segments | Segment				3
Segment Reporting Information [Line Items]
Purchased oil and gas sales	$ 0			$ 0	$ 0
Lease operating expenses	311,000,000	$ 264,000,000		575,000,000	599,000,000
Taxes other than income	51,000,000	23,000,000		95,000,000	56,000,000
Exploration	19,000,000	72,000,000		65,000,000	129,000,000
Depreciation, depletion, and amortization	351,000,000	418,000,000		693,000,000	984,000,000
Asset retirement obligation accretion	28,000,000	27,000,000		56,000,000	54,000,000
Impairments	0	20,000,000	$ 4,500,000,000	0	4,492,000,000
Total operating expenses	1,083,000,000	942,000,000		2,359,000,000	6,589,000,000
Operating income	673,000,000	(190,000,000)		1,268,000,000	(4,493,000,000)
Other Income (Expense):
Derivative instrument gains (losses), net	(113,000,000)	(175,000,000)		45,000,000	(278,000,000)
Gain on divestitures, net	65,000,000	0		67,000,000	25,000,000
Other	74,000,000	19,000,000		135,000,000	32,000,000
General and administrative	(79,000,000)	(94,000,000)		(162,000,000)	(162,000,000)
Transaction, reorganization, and separation	(4,000,000)	(10,000,000)		(4,000,000)	(37,000,000)
Financing costs, net	(94,000,000)	34,000,000		(201,000,000)	(69,000,000)
NET INCOME (LOSS) BEFORE INCOME TAXES	522,000,000	(416,000,000)		1,148,000,000	(4,982,000,000)
Total assets	14,388,000,000	12,999,000,000		14,388,000,000	12,999,000,000	$ 12,746,000,000
Operating Segments | Egypt
Segment Reporting Information [Line Items]
Lease operating expenses	114,000,000	98,000,000		218,000,000	210,000,000
Taxes other than income	0	0		0	0
Exploration	14,000,000	22,000,000		22,000,000	40,000,000
Depreciation, depletion, and amortization	137,000,000	158,000,000		267,000,000	319,000,000
Asset retirement obligation accretion	0	0		0	0
Impairments		20,000,000			529,000,000
Total operating expenses	268,000,000	311,000,000		511,000,000	1,121,000,000
Operating income	231,000,000	(53,000,000)		462,000,000	(462,000,000)
Other Income (Expense):
Total assets	3,116,000,000	3,098,000,000		3,116,000,000	3,098,000,000
Impairments of oil and gas properties	2,000,000	22,000,000		4,000,000	533,000,000
Operating Segments | North Sea
Segment Reporting Information [Line Items]
Lease operating expenses	98,000,000	75,000,000		173,000,000	156,000,000
Taxes other than income	0	0		0	0
Exploration	3,000,000	15,000,000		23,000,000	17,000,000
Depreciation, depletion, and amortization	63,000,000	79,000,000		147,000,000	188,000,000
Asset retirement obligation accretion	20,000,000	18,000,000		39,000,000	36,000,000
Impairments		0			7,000,000
Total operating expenses	192,000,000	198,000,000		402,000,000	431,000,000
Operating income	55,000,000	(60,000,000)		123,000,000	4,000,000
Other Income (Expense):
Total assets	2,127,000,000	2,339,000,000		2,127,000,000	2,339,000,000
Impairments of oil and gas properties					7,000,000
Operating Segments | U.S.
Segment Reporting Information [Line Items]
Lease operating expenses	99,000,000	90,000,000		185,000,000	233,000,000
Taxes other than income	47,000,000	20,000,000		87,000,000	49,000,000
Exploration	2,000,000	31,000,000		18,000,000	66,000,000
Depreciation, depletion, and amortization	148,000,000	178,000,000		273,000,000	471,000,000
Asset retirement obligation accretion	7,000,000	8,000,000		15,000,000	16,000,000
Impairments		0			3,956,000,000
Total operating expenses	636,000,000	443,000,000		1,472,000,000	5,067,000,000
Operating income	371,000,000	(88,000,000)		651,000,000	(4,066,000,000)
Other Income (Expense):
Total assets	7,305,000,000	5,821,000,000		7,305,000,000	5,821,000,000
Impairments of oil and gas properties	1,000,000	29,000,000		17,000,000	4,000,000,000.0
Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Purchased oil and gas sales	32,000,000	31,000,000		64,000,000	72,000,000
Lease operating expenses	0	0		0	0
Taxes other than income	4,000,000	3,000,000		8,000,000	7,000,000
Exploration	0	0		0	0
Depreciation, depletion, and amortization	3,000,000	3,000,000		6,000,000	6,000,000
Asset retirement obligation accretion	1,000,000	1,000,000		2,000,000	2,000,000
Impairments		0			0
Total operating expenses	19,000,000	17,000,000		36,000,000	36,000,000
Operating income	16,000,000	15,000,000		34,000,000	37,000,000
Other Income (Expense):
Total assets	1,839,000,000	1,627,000,000		1,839,000,000	1,627,000,000
Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Purchased oil and gas sales	(32,000,000)	(31,000,000)		(64,000,000)	(72,000,000)
Lease operating expenses	0	1,000,000		(1,000,000)	0
Taxes other than income	0	0		0	0
Exploration	0	4,000,000		2,000,000	6,000,000
Depreciation, depletion, and amortization	0	0		0	0
Asset retirement obligation accretion	0	0		0	0
Impairments		0			0
Total operating expenses	(32,000,000)	(27,000,000)		(62,000,000)	(66,000,000)
Operating income	0	(4,000,000)		(2,000,000)	(6,000,000)
Other Income (Expense):
Total assets	1,000,000	114,000,000		1,000,000	114,000,000
Oil and gas
Segment Reporting Information [Line Items]
Total revenues	1,756,000,000	752,000,000		3,627,000,000	2,096,000,000
Oil and gas | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Total revenues	499,000,000	258,000,000		973,000,000	659,000,000
Oil and gas | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Total revenues	247,000,000	138,000,000		525,000,000	435,000,000
Oil and gas | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Total revenues	1,007,000,000	355,000,000		2,123,000,000	1,001,000,000
Oil and gas | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Total revenues	35,000,000	32,000,000		70,000,000	73,000,000
Oil and gas | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Total revenues	(32,000,000)	(31,000,000)		(64,000,000)	(72,000,000)
Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	1,514,000,000	697,000,000		2,945,000,000	1,933,000,000
Purchased oil and gas sales	1,407,000,000	715,000,000		2,732,000,000	1,903,000,000
Cost of goods and services sold	61,000,000	72,000,000		119,000,000	143,000,000
Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	499,000,000	258,000,000		973,000,000	659,000,000
Cost of goods and services sold	3,000,000	13,000,000		4,000,000	23,000,000
Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	247,000,000	138,000,000		525,000,000	435,000,000
Cost of goods and services sold	8,000,000	11,000,000		20,000,000	27,000,000
Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	768,000,000	301,000,000		1,447,000,000	839,000,000
Cost of goods and services sold	74,000,000	70,000,000		143,000,000	145,000,000
Oil and gas, excluding purchased | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	0	0		0	0
Cost of goods and services sold	8,000,000	10,000,000		15,000,000	20,000,000
Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Cost of goods and services sold	(32,000,000)	(32,000,000)		(63,000,000)	(72,000,000)
Oil and gas, purchased
Segment Reporting Information [Line Items]
Purchased oil and gas sales	242,000,000	55,000,000		682,000,000	163,000,000
Cost of goods and services sold	262,000,000	46,000,000		756,000,000	132,000,000
Oil and gas, purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Purchased oil and gas sales	0	0		0	0
Cost of goods and services sold	0	0		0	0
Oil and gas, purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Purchased oil and gas sales	0	0		0	0
Cost of goods and services sold	0	0		0	0
Oil and gas, purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Purchased oil and gas sales	239,000,000	54,000,000		676,000,000	162,000,000
Cost of goods and services sold	259,000,000	46,000,000		751,000,000	131,000,000
Oil and gas, purchased | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Purchased oil and gas sales	3,000,000	1,000,000		6,000,000	1,000,000
Cost of goods and services sold	3,000,000	0		5,000,000	1,000,000
Oil and gas, purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Purchased oil and gas sales	0	0		0	0
Cost of goods and services sold	0	0		0	0
Oil | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	1,141,000,000	513,000,000		2,132,000,000	1,545,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	432,000,000	187,000,000		834,000,000	520,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	216,000,000	128,000,000		457,000,000	399,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	493,000,000	198,000,000		841,000,000	626,000,000
Oil | Oil and gas, excluding purchased | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	0	0		0	0
Oil | Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	0			0	0
Natural Gas | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	226,000,000	130,000,000		538,000,000	253,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	65,000,000	70,000,000		135,000,000	135,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	27,000,000	7,000,000		58,000,000	26,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	134,000,000	53,000,000		345,000,000	92,000,000
Natural Gas | Oil and gas, excluding purchased | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	0	0		0	0
Natural Gas | Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	0			0	0
Natural Gas liquids | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	147,000,000	54,000,000		275,000,000	135,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	2,000,000	1,000,000		4,000,000	4,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	4,000,000	3,000,000		10,000,000	10,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	141,000,000	50,000,000		261,000,000	121,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	0	$ 0		0	0
Natural Gas liquids | Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues	$ 0			$ 0	$ 0