Restructuring Costs - Schedule of Restructuring Costs Expected, Incurred, and Remaining (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Current Year Actions
Restructuring Reserve [Roll Forward]
Expected Costs	$ 58
Cost Incurred	(19)	$ (19)	$ (4)
Remaining Costs	16
Prior Year Actions
Restructuring Reserve [Roll Forward]
Expected Costs	52
Cost Incurred	(1)	$ (1)	$ (2)	$ (45)
Remaining Costs	$ 3