Revenue - Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue from customers	$ 3,308	$ 3,731	$ 8,558	$ 7,166
All other revenue	(380)	689	983	1,258
Revenues, Total	$ 2,928	$ 4,420	$ 9,541	$ 8,424