SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Asset Impairments Recorded in Connection with Fair Value Assessments (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Significant Accounting Policies [Line Items]
Impairments	$ 1,400	$ 639	$ 49	$ 21	$ 16	$ 2,949	$ 511	$ 8
Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments						1,484	328	0
GPT facilities
Schedule Of Significant Accounting Policies [Line Items]
Impairments						1,295	56	0
Equity method investment
Schedule Of Significant Accounting Policies [Line Items]
Impairments						0	113	0
Divested unproved properties and leasehold
Schedule Of Significant Accounting Policies [Line Items]
Impairments						149	10	0
Inventory and other
Schedule Of Significant Accounting Policies [Line Items]
Impairments						$ 21	$ 4	$ 8