Restructuring Programs (Details) $ in Millions		3 Months Ended
		Mar. 31, 2017 USD ($) Employees	Mar. 31, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1]	$ 110
Restructuring and Related Cost, Expected Number of Positions Eliminated (approximately) | Employees		1,000
Three-Year Strategic Transformation Program - Professional Support Services		$ 10
Reversals		(2)
Restructuring Charges		112
Restructuring Reserve [Roll Forward]
Balance at beginning of period		127
Provision		112
Reversals		(2)
Net Current Period Charges	[1]	110
Charges against reserve		(59)	$ (19)
Balance at end of period		178
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve		(59)	(19)
Asset impairments		0	0
Effects of foreign currency and other non-cash items		(1)	(2)
Restructuring Cash Payments		(60)	$ (21)
Severance and Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1]	108
Reversals		(2)
Restructuring Charges		110
Restructuring Reserve [Roll Forward]
Balance at beginning of period		104
Provision		110
Reversals		(2)
Net Current Period Charges	[1]	108
Charges against reserve		(58)
Balance at end of period		154
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve		(58)
Lease Cancellation and Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1]	2
Reversals		0
Restructuring Charges		2
Restructuring Reserve [Roll Forward]
Balance at beginning of period		23
Provision		2
Reversals		0
Net Current Period Charges	[1]	2
Charges against reserve		(1)
Balance at end of period		24
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve		(1)
Asset Impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, Net Current Period Charges	[1],[2]	0
Reversals	[2]	0
Restructuring Charges	[2]	0
Restructuring Reserve [Roll Forward]
Balance at beginning of period		0
Provision	[2]	0
Reversals	[2]	0
Net Current Period Charges	[1],[2]	0
Charges against reserve	[2]	0
Balance at end of period		0
Reconciliation To Consolidated Statements Of Cash Flows [Abstract]
Charges against reserve	[2]	$ 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.