Segment and Related Information, Reconciliation of EBITDA to income (loss) from continuing operations before income taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
EBITDA: [Abstract]
Total segment EBITDA	$ 767	$ 1,575	$ 1,422	$ 2,993
Other EBITDA	(7)	4	(16)	14
Less: [Abstract]
Depreciation and amortization expense	(356)	(328)	(698)	(650)
Interest expense	(125)	(81)	(214)	(173)
Add: [Abstract]
Interest income	4	5	7	11
Income from continuing operations before income taxes	$ 283	$ 1,175	$ 501	$ 2,195