Restructuring Programs - Information Related to Restructuring Program Activity (Details) - USD ($) $ in Millions		3 Months Ended							9 Months Ended
		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Balance at beginning of period		$ 69		$ 80		$ 95			$ 95
Provision		15		26		62
Reversals		(7)		(8)		(8)			(23)
Net current period charges	[1]	8		18		54			80
Charges against reserve and currency		(20)		(29)		(69)		$ (38)	(118)	$ (130)
Balance at end of period		57		69		80			57
Leased right-of-use asset write-off	[2]								36
Owned asset write-off	[2]								12
Severance and Related Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period		56		66		94			94
Provision		12		13		12			37
Reversals		(3)		(6)		(8)
Net current period charges	[1]	9		7		4
Charges against reserve and currency		(16)		(17)		(32)
Balance at end of period		49		56		66			49
Other Contractual Termination Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	[3]	13		14		1			1
Provision		1	[3]	3	[3]	14	[3]		18
Reversals	[3]	(3)		0		0
Net current period charges	[1],[3]	(2)		3		14
Charges against reserve and currency	[3]	(3)		(4)		(1)
Balance at end of period	[3]	8		13		14			8
Asset Impairments
Restructuring Reserve [Roll Forward]
Balance at beginning of period	[2]	0		0		0			0
Provision	[2]	2		10		36			48
Reversals	[2]	(1)		(2)		0
Net current period charges	[1],[2]	1		8		36
Charges against reserve and currency	[2]	(1)		(8)		(36)
Balance at end of period	[2]	$ 0		$ 0		$ 0			$ 0

[1] Represents net amount recognized within the Condensed Consolidated Statements of Income for the period shown for restructuring and asset impairment charges.

[2] Primarily related to the exit and abandonment of leased and owned facilities. The charge includes the accelerated write-off of $36 for leased right-of-use asset balances and $12 for owned asset balances upon exit from the facility net of any potential sublease income or other recovery amounts.

[3] Primarily includes additional costs incurred upon the exit from our facilities including decommissioning costs and associated contractual termination costs.