Restructuring Programs - Restructuring Program Activity (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 45	$ 63	$ 82		$ 82
Provision	6	9	25
Reversals	(3)	(5)	(4)		(12)
Net current period charges	3	4	21		28
Charges against reserve and currency	(12)	(22)	(40)	$ (13)	(74)	$ (61)
Balance at end of period	36	45	63		36
Leased right-of-use asset write-off					3
Owned asset write-off					9
Severance and Related Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	42	59	78		78
Provision	5	6	14		25
Reversals	(3)	(3)	(4)
Net current period charges	2	3	10
Charges against reserve and currency	(11)	(20)	(29)
Balance at end of period	33	42	59		33
Other Contractual Termination Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	3	4	4		4
Provision	1	1	1		3
Reversals	0	(1)	0
Net current period charges	1	0	1
Charges against reserve and currency	(1)	(1)	(1)
Balance at end of period	3	3	4		3
Asset Impairments
Restructuring Reserve [Roll Forward]
Balance at beginning of period	0	0	0		0
Provision	0	2	10		12
Reversals	0	(1)	0
Net current period charges	0	1	10
Charges against reserve and currency	0	(1)	(10)
Balance at end of period	$ 0	$ 0	$ 0		$ 0