SUPPLEMENTAL INFORMATION ON OIL AND NATURAL GAS OPERATIONS (Unaudited) - Principal Changes in Standardized Measure of Discounted Future Net Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Standardized measure of discounted future net cash flows at the beginning of the period	$ 11,676	$ 3,757	$ 1,711
Sales of oil and natural gas, net of production costs	(3,334)	(1,786)	(986)
Acquisition of reserves	309	5,520	439
Divestiture of reserves	(500)	(2)	(11)
Extensions and discoveries, net of future development costs	4,004	3,287	1,792
Previously estimated development costs incurred during the period	120	535	190
Net changes in prices and production costs	831	1,805	578
Changes in estimated future development costs	(3,190)	(81)	(53)
Revisions of previous quantity estimates	(1,242)	271	(99)
Accretion of discount	1,344	380	174
Net change in income taxes	693	(1,728)	(9)
Net changes in timing of production and other	(527)	(282)	31
Standardized measure of discounted future net cash flows at the end of the period	$ 10,184	$ 11,676	$ 3,757