Restructuring Charges, Net and Asset Impairments - Roll Forward of Restructuring Reserve (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 99	$ 99	$ 100	$ 140	$ 83	$ 101	$ 100	$ 101
Provisions	5	32	34	19	96	15
Revisions to estimates	(10)	(8)	(9)	(5)	(4)	(2)
Payments	(16)	(24)	(25)	(28)	(35)	(30)
Foreign currency	(1)		(1)	1		(1)
Restructuring reserve, ending balance	77	99	99	127	140	83	77	127
Employee Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	99	99	99	136	81	97	99	97
Provisions	2	30	31	16	90	10
Revisions to estimates	(10)	(8)	(9)	(4)	(4)	(2)
Payments	(13)	(22)	(21)	(24)	(31)	(23)
Foreign currency	(1)		(1)	1		(1)
Restructuring reserve, ending balance	77	99	99	125	136	81	77	125
Facility Closure and Other Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0	0	1	4	2	4	1	4
Provisions	3	2	3	3	6	5
Revisions to estimates	0	0	0	(1)	0	0
Payments	(3)	(2)	(4)	(4)	(4)	(7)
Foreign currency	0		0	0		0
Restructuring reserve, ending balance	$ 0	$ 0	$ 0	$ 2	$ 4	$ 2	$ 0	$ 2