SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Revenues from Contracts with Customers and Non-customers (Details) - Oil and gas, excluding purchased - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule Of Significant Accounting Policies [Line Items]
Production revenues from customers	$ 1,562	$ 1,002	$ 4,294	$ 2,905
Production revenues from non-customers	123	44	336	74
Total production revenues	$ 1,685	$ 1,046	$ 4,630	$ 2,979