BUSINESS SEGMENT INFORMATION - Financial Segment Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Expenses:
Lease operating expenses		$ 1,241	$ 1,127	$ 1,447
Taxes other than income		204	123	207
Exploration		127	274	805
Depreciation, depletion, and amortization		1,360	1,772	2,680
Asset retirement obligation accretion		113	109	107
Impairments	$ 1,400	208	4,501	2,949
Total operating expenses		5,097	8,537	8,643
Operating Income (Loss)		2,888	(4,102)	(2,152)
Other Income (Expense):
Gain on divestitures, net		67	32	43
Loss on previously sold Gulf of Mexico properties		(446)
Derivative instrument gains (losses), net		94	(223)	(35)
Other		228	64	54
General and administrative		(357)	(290)	(406)
Transaction, reorganization, and separation		(22)	(54)	(50)
Financing costs, net		(472)	(267)	(462)
Net income (loss) before income taxes		1,980	(4,840)	(3,008)
Total assets	18,107	14,393	12,746	18,107
Net Property and Equipment	14,158	8,060	8,819	14,158
Additions to Net Property and Equipment	2,734	1,004	1,162	2,734
Operating Segments | Egypt
Operating Expenses:
Lease operating expenses		469	424	484
Taxes other than income		0	0	0
Exploration		63	63	100
Depreciation, depletion, and amortization		524	601	708
Asset retirement obligation accretion		0	0	0
Impairments		26	529	0
Total operating expenses		1,094	1,655	1,332
Operating Income (Loss)		991	(265)	944
Other Income (Expense):
Total assets	3,700	2,796	3,003	3,700
Net Property and Equipment	2,573	1,720	1,955	2,573
Additions to Net Property and Equipment	454	319	454	454
Operating Segments | North Sea
Operating Expenses:
Lease operating expenses		383	305	320
Taxes other than income		0	0	0
Exploration		34	28	2
Depreciation, depletion, and amortization		270	380	366
Asset retirement obligation accretion		79	73	76
Impairments		22	7	0
Total operating expenses		827	843	809
Operating Income (Loss)		309	40	467
Other Income (Expense):
Total assets	2,473	2,199	2,220	2,473
Net Property and Equipment	1,956	1,646	1,773	1,956
Additions to Net Property and Equipment	183	159	215	183
Operating Segments | U.S.
Operating Expenses:
Lease operating expenses		391	400	645
Taxes other than income		190	108	194
Exploration		28	168	688
Depreciation, depletion, and amortization		554	779	1,566
Asset retirement obligation accretion		30	32	29
Impairments		0	3,963	1,648
Total operating expenses		3,077	6,095	5,211
Operating Income (Loss)		1,679	(3,937)	(2,272)
Other Income (Expense):
Total assets	10,388	7,700	5,540	10,388
Net Property and Equipment	9,385	4,507	4,760	9,385
Additions to Net Property and Equipment	1,696	523	345	1,696
Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues		(127)	(145)	(136)
Operating Expenses:
Lease operating expenses		(2)	(2)	(2)
Taxes other than income		0	0	0
Exploration		2	15	15
Depreciation, depletion, and amortization		0	0	0
Asset retirement obligation accretion		0	0	0
Impairments		0	0	0
Total operating expenses		(128)	(130)	(121)
Operating Income (Loss)		(2)	(15)	(15)
Other Income (Expense):
Total assets	67	0	197	67
Net Property and Equipment	38	0	135	38
Additions to Net Property and Equipment	93	0	136	93
Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues		127	145	136
Operating Expenses:
Lease operating expenses		0	0	0
Taxes other than income		14	15	13
Exploration		0	0	0
Depreciation, depletion, and amortization		12	12	40
Asset retirement obligation accretion		4	4	2
Impairments		160	2	1,301
Total operating expenses		227	74	1,412
Operating Income (Loss)		(89)	75	(1,276)
Other Income (Expense):
Total assets	1,479	1,698	1,786	1,479
Net Property and Equipment	206	187	196	206
Additions to Net Property and Equipment	$ 308	3	12	308
Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		6,498	4,037	6,315
Operating Expenses:
Gathering, processing, and transmission		264	274	306
Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		2,085	1,390	2,276
Operating Expenses:
Gathering, processing, and transmission		12	38	40
Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		1,136	883	1,276
Operating Expenses:
Gathering, processing, and transmission		39	50	45
Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		3,280	1,764	2,763
Operating Expenses:
Gathering, processing, and transmission		309	291	299
Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		(3)
Operating Expenses:
Gathering, processing, and transmission		(128)	(143)	(134)
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
Operating Expenses:
Gathering, processing, and transmission		32	38	56
Oil and gas, purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues		1,487	398	176
Operating Expenses:
Gathering, processing, and transmission		1,580	357	142
Oil and gas, purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues		0	0	0
Operating Expenses:
Gathering, processing, and transmission		0	0	0
Oil and gas, purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues		0	0	0
Operating Expenses:
Gathering, processing, and transmission		0	0	0
Oil and gas, purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues		1,476	394	176
Operating Expenses:
Gathering, processing, and transmission		1,575	354	142
Oil and gas, purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues		0	0	0
Operating Expenses:
Gathering, processing, and transmission		0	0	0
Oil and gas, purchased | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues		11	4	0
Operating Expenses:
Gathering, processing, and transmission		5	3	0
Oil and gas
Segment Reporting Information [Line Items]
Total revenues		7,985	4,435	6,491
Oil and gas | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Total revenues		2,085	1,390	2,276
Oil and gas | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Total revenues		1,136	883	1,276
Oil and gas | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Total revenues		4,756	2,158	2,939
Oil and gas | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Total revenues		(130)	(145)	(136)
Oil and gas | Reportable Legal Entities | Altus Midstream
Segment Reporting Information [Line Items]
Total revenues		138	149	136
Oil
Other Income (Expense):
Revenue from non-customers		420	95	410
Oil | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		4,585	3,106	5,230
Oil | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		1,806	1,102	1,969
Oil | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		929	795	1,163
Oil | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		1,850	1,209	2,098
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
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
Natural Gas
Other Income (Expense):
Revenue from non-customers		47	14	40
Natural Gas | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		1,207	598	678
Natural Gas | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		270	280	295
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		183	67	90
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		754	251	293
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 | 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
Natural Gas Liquids
Other Income (Expense):
Revenue from non-customers		2	0	1
Natural Gas Liquids | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil, natural gas, and natural gas liquids production revenues		706	333	407
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		9	8	12
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		24	21	23
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		676	304	372
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		(3)	0	0
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