SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - ASSET IMPAIRMENTS (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of significant accounting policies
Crude oil supply agreements termination costs	$ 160			$ 160
Other impairments				619
Qatar ISND and ISSD
Summary of significant accounting policies
Impairments of assets		$ 416
Net proved property balance		149
Oman
Summary of significant accounting policies
Net proved property balance		1,700
Proved and unproved non-core Permian
Summary of significant accounting policies
Impairments of assets			$ 397
Libya
Summary of significant accounting policies
Impairments of assets				$ 46
Midstream and Marketing
Summary of significant accounting policies
Impairments of assets		$ 100
Other asset impairment related charges			$ 120