SUPPLEMENTAL FINANCIAL STATEMENT INFORMATION Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Disclosure Text Block Supplement [Abstract]
Temporary investments	$ 501		$ 501		$ 335
Allowance for doubtful accounts	85		85		73
Accumulated depreciation	20,700		20,700		20,500
Depreciation expense	293	$ 300	602	$ 597
Capital expenditures incurred but not yet paid			50	164
Interest payments			338	375
Asset retirement obligation	$ 97		97		$ 96
Insurance Recoveries			$ 30	$ 0