Segment and Related Information, Reconciliation of EBITDA to income (loss) from continuing operations before income taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
EBITDA: [Abstract]
Total segment EBITDA	$ 465	$ 1,513	$ 1,887	$ 4,506
Other EBITDA	1	0	(15)	14
Less: [Abstract]
Depreciation and amortization expense	(358)	(327)	(1,056)	(977)
Interest expense	(122)	(86)	(336)	(259)
Add: [Abstract]
Interest income	3	5	10	16
(Loss) income from continuing operations before income taxes	$ (11)	$ 1,105	$ 490	$ 3,300