SUPPLEMENTAL FINANCIAL STATEMENT INFORMATION Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Disclosure Text Block Supplement [Abstract]
Temporary investments	$ 491		$ 358
Allowance for doubtful accounts	70		76
Accumulated depreciation	20,700		21,400
Depreciation expense	294	$ 309
Interest payments	112	184
Asset retirement obligation	113		116
Accounts Payable, Other	40		$ 41
Insurance Recoveries	$ 2	$ 30