SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule Of Significant Accounting Policies [Line Items]
Impairments	$ 20	$ 4,500	$ 240	$ 4,492	$ 240
Impairments of oil and gas properties	20		240	4,492	240
Goodwill	0	87	0	87	0
Impairment for early termination of drilling rig leases		13
Inventory write-down		5
Divested unproved properties and leasehold	0		149	0	149
Receivables from contracts with customer, net	768			768		$ 945
Transaction, reorganization, and separation	10		6	37	10
Reorganization
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation	9
Restructuring cumulative cost incurred to date	62			62
Cash payments for restructuring				58
Reorganization | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Estimated additional restructuring expenses	5			5
Reorganization | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Estimated additional restructuring expenses	10			10
Office closure
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation	1
Separation costs
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation				25
Consulting fees
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation				2
Oil and gas, purchased
Schedule Of Significant Accounting Policies [Line Items]
Oil and gas production revenues	55		18	163	42
Cost of goods and services sold	46		15	132	37
Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	20		86	4,319	86
Oil and gas properties impaired, fair value	$ 32	1,900		$ 32
Oil and gas proved property | Discount Rate | Significant Unobservable Inputs (Level 3)
Schedule Of Significant Accounting Policies [Line Items]
Oil and gas properties, measurement inputs	0.10			0.10
Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 31		188	$ 50	211
Gathering, processing, and transmission facilities
Schedule Of Significant Accounting Policies [Line Items]
Impairments		68
Oil and gas properties impaired, fair value	$ 46			$ 46
Gathering, processing, and transmission facilities | Discount Rate | Significant Unobservable Inputs (Level 3)
Schedule Of Significant Accounting Policies [Line Items]
Oil and gas properties, measurement inputs	0.10			0.10
U.S. | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 0	3,900	86	$ 3,938	86
U.S. | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	29		186	46	207
Egypt | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	20	354	0	374	0
Egypt | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	2		2	4	4
North Sea | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 0	$ 7	0	$ 7	$ 0
Oklahoma And Texas
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties			240
Oklahoma And Texas | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties			86
Oklahoma And Texas | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties			149
Divested unproved properties and leasehold			149
Oklahoma And Texas | Other working capital
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties			$ 5
Altus Midstream Company
Schedule Of Significant Accounting Policies [Line Items]
Ownership percentage by noncontrolling owners	21.00%			21.00%