Restructuring Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 96
Restructuring Charges	43	$ 3	$ 3
Payments made during the period	(33)	$ (9)
Foreign currency and other	(2)
Ending Balance	104		96
Employee Termination Benefits Liability
Restructuring Reserve [Roll Forward]
Beginning Balance	95
Restructuring Charges	43
Payments made during the period	(33)
Foreign currency and other	(2)
Ending Balance	103		95
Other Exit Costs Liability
Restructuring Reserve [Roll Forward]
Beginning Balance	1
Restructuring Charges	0
Payments made during the period	0
Foreign currency and other	0
Ending Balance	$ 1		$ 1