Restructuring Programs - Information Related to Restructuring Program Activity (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 49	$ 64	$ 70		$ 70
Provision	23	7	35
Reversals	(3)	(9)	(6)		(18)
Net current period charges	20	(2)	29		47
Charges against reserve and currency	(13)	(13)	(35)	$ (20)	(61)	$ (118)
Balance at end of period	56	49	64		56
Restructuring reserve, reclassification to other assets					4
Leased right-of-use asset write-off					3
Owned asset write-off					3
Severance and Related Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	44	57	66		66
Provision	18	7	32		57
Reversals	(2)	(6)	(5)
Net current period charges	16	1	27
Charges against reserve and currency	(8)	(14)	(36)
Balance at end of period	52	44	57		52
Other Contractual Termination Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	5	7	4		4
Provision	1	0	1		2
Reversals	0	(1)	0
Net current period charges	1	(1)	1
Charges against reserve and currency	(2)	(1)	2
Balance at end of period	4	5	7		4
Asset Impairments
Restructuring Reserve [Roll Forward]
Balance at beginning of period	0	0	0		0
Provision	4	0	2		6
Reversals	(1)	(2)	(1)
Net current period charges	3	(2)	1
Charges against reserve and currency	(3)	2	(1)
Balance at end of period	$ 0	$ 0	$ 0		$ 0