SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Non-Cash Impairments of Proved and Unproved Property and Equipment (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
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	$ 20		$ 240	$ 4,492	$ 240
Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	20		86	4,319	86
Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	31		188	50	211
U.S. | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	0	$ 3,900	86	3,938	86
U.S. | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	29		186	46	207
Egypt | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	20	354	0	374	0
Egypt | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	2		2	4	4
North Sea | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	$ 0	$ 7	$ 0	$ 7	$ 0