Restructuring Programs (Details) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Employees	Jun. 30, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1]	$ 34	$ 28		$ 62
Restructuring Charges		40	36
Restructuring and Related Cost, Expected Number of Positions Eliminated (approximately) | Employees					950
Reversals		(6)	(8)		$ (14)
Restructuring Reserve [Roll Forward]
Balance at beginning of period		85	109		109
Provision		40	36
Reversals		(6)	(8)		(14)
Net Current Period Charges	[1]	34	28		62
Charges against reserve and currency		(40)	(52)	$ (59)	(92)	$ (116)
Balance at end of period		79	85		79
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve and currency		(40)	(52)	(59)	(92)	(116)
Effects of foreign currency and other non-cash items		3		(7)	1	(8)
Restructuring Cash Payments		(37)		$ (66)	(91)	$ (124)
Severance and Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1]	34	16
Restructuring Charges		40	24		64
Reversals		(6)	(8)
Restructuring Reserve [Roll Forward]
Balance at beginning of period		83	108		108
Provision		40	24		64
Reversals		(6)	(8)
Net Current Period Charges	[1]	34	16
Charges against reserve and currency		(39)	(41)
Balance at end of period		78	83		78
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve and currency		(39)	(41)
Lease Cancellation and Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1]	0	12
Restructuring Charges		0	12		12
Reversals		0	0
Restructuring Reserve [Roll Forward]
Balance at beginning of period		2	1		1
Provision		0	12		12
Reversals		0	0
Net Current Period Charges	[1]	0	12
Charges against reserve and currency		(1)	(11)
Balance at end of period		1	2		1
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve and currency		(1)	(11)
Asset Impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1],[2]	0	0
Restructuring Charges	[2]	0	0
Reversals	[2]	0	0
Restructuring Reserve [Roll Forward]
Balance at beginning of period	[2]	0	0		0
Provision	[2]	0	0
Reversals	[2]	0	0
Net Current Period Charges	[1],[2]	0	0
Charges against reserve and currency	[2]	0	0
Balance at end of period	[2]	0	0		$ 0
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve and currency	[2]	$ 0	$ 0

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

[2] Charges associated with asset impairments represent the write-down of the related assets to their new cost basis and are recorded concurrently with the recognition of the provision.