SUPPLEMENTAL OIL AND GAS DISCLOSURES (Unaudited) - Future Net Cash Flows (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	$ 39,755	$ 37,204
Production costs	(14,826)	(15,662)
Development costs	(5,506)	(6,739)
Income tax expense	(2,473)	(1,815)
Net cash flows	16,950	12,988
10 percent discount rate	(6,867)	(4,928)
Discounted future net cash flows	$ 10,083	8,060
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	$ 12,200	9,500
Egypt
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	9,254	8,778
Production costs	(1,749)	(1,967)
Development costs	(1,052)	(1,111)
Income tax expense	(2,078)	(1,775)
Net cash flows	4,375	3,925
10 percent discount rate	(1,034)	(956)
Discounted future net cash flows	3,341	2,969
Egypt | Noncontrolling Interest
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Discounted future net cash flows	1,100	1,000
United States
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	24,271	20,067
Production costs	(10,618)	(8,858)
Development costs	(1,659)	(1,653)
Income tax expense	(42)	(32)
Net cash flows	11,952	9,524
10 percent discount rate	(6,080)	(5,319)
Discounted future net cash flows	5,872	4,205
Canada
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	0	3,625
Production costs	0	(2,582)
Development costs	0	(1,565)
Income tax expense	0	0
Net cash flows	0	(522)
10 percent discount rate	0	549
Discounted future net cash flows	0	27
North Sea
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Cash inflows	6,230	4,734
Production costs	(2,459)	(2,255)
Development costs	(2,795)	(2,410)
Income tax expense	(353)	(8)
Net cash flows	623	61
10 percent discount rate	247	798
Discounted future net cash flows	$ 870	$ 859