Segments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information, Profit (Loss)
Operating revenue	$ 1,468	$ 12,536	$ 10,060	$ 23,008
Intersegment Sales/Other | Exchanged products
Segment Reporting Information, Profit (Loss)
Operating revenue	$ (65)	$ (1,078)	$ (895)	$ (1,811)