SUPPLEMENTAL OIL AND GAS DISCLOSURES (Unaudited) - Future Net Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	$ 22,219	$ 37,454	$ 48,978
Production costs	(10,336)	(15,219)	(18,086)
Development costs	(4,636)	(5,098)	(5,656)
Income tax expense	(780)	(2,741)	(3,826)
Net cash flows	6,467	14,396	21,410
10 percent discount rate	(1,155)	(4,514)	(7,689)
Discounted future net cash flows	$ 5,312	9,882	13,721
Estimated future net cash flow before income tax expenses	10.00%
Total estimated future net cash flows before income tax expense discounted at 10 percent per annum	$ 7,100	12,400	16,900
United States
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	12,537	21,694	29,906
Production costs	(6,244)	(10,642)	(13,699)
Development costs	(1,555)	(1,740)	(2,150)
Income tax expense	0	(27)	(19)
Net cash flows	4,738	9,285	14,038
10 percent discount rate	(1,829)	(4,003)	(6,516)
Discounted future net cash flows	2,909	5,282	7,522
Egypt
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	5,560	8,306	9,866
Production costs	(1,704)	(1,847)	(1,799)
Development costs	(633)	(707)	(792)
Income tax expense	(1,096)	(1,930)	(2,455)
Net cash flows	2,127	3,822	4,820
10 percent discount rate	(437)	(808)	(1,066)
Discounted future net cash flows	1,690	3,014	3,754
Egypt | Noncontrolling Interests
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Discounted future net cash flows	563	1,000	1,300
North Sea
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	4,122	7,454	9,206
Production costs	(2,388)	(2,730)	(2,588)
Development costs	(2,448)	(2,651)	(2,714)
Income tax expense	316	(784)	(1,352)
Net cash flows	(398)	1,289	2,552
10 percent discount rate	1,111	297	(107)
Discounted future net cash flows	$ 713	$ 1,586	$ 2,445