Fair Value Measurements Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 2,915		$ 2,915		$ 2,271
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	27	$ 32	55	$ 80
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Ending Balance	25		25		102
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net	2,197		2,197		1,830
Unamortized gains on senior notes	45		45		51
Unrealized gain on interest rate cash flow hedges, pretax, AOCI	8		8		9
reduction of interest expense, related to amortization of previously terminated interest rate contracts	3	3	6	6
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	14		14
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net			0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net			1
Derivative Assets	96		96		199
Derivative Liabilities	70		70		26
Available-for-sale Securities	30		30		20
Time Deposits, at Carrying Value					19
Cash	129		129		135
Cost-method Investments, Aggregate Carrying Amount	42		42		20
Debt Instrument, Fair Value Disclosure	6,174		6,174		5,739
Fair Value, Measurements, Recurring [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	66		66		42
Available-for-sale Securities	30		30		20
Foreign Currency Contract, Asset, Fair Value Disclosure	96		96		199
Assets, Fair Value Disclosure	192		192		261
Foreign Currency Contracts, Liability, Fair Value Disclosure	70		70		26
Accrued Contingent Consideration	102		102		204
Liabilities, Fair Value Disclosure	172		172		230
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	66		66		42
Available-for-sale Securities	30		30		20
Assets, Fair Value Disclosure	96		96		62
Foreign Currency Contracts, Liability, Fair Value Disclosure	0		0		0
Accrued Contingent Consideration	0		0		0
Liabilities, Fair Value Disclosure	0		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	0		0		0
Available-for-sale Securities	0		0		0
Foreign Currency Contract, Asset, Fair Value Disclosure	96		96		199
Assets, Fair Value Disclosure	96		96		199
Foreign Currency Contracts, Liability, Fair Value Disclosure	70		70		26
Accrued Contingent Consideration	0		0		0
Liabilities, Fair Value Disclosure	70		70		26
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	0		0		0
Available-for-sale Securities	0		0		0
Assets, Fair Value Disclosure	0		0		0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0		0		0
Accrued Contingent Consideration	102		102		204
Liabilities, Fair Value Disclosure	102		102		204
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	72		72		163
Derivative Instruments in Hedges, Liabilities, at Fair Value	36		36		7
Designated as Hedging Instrument [Member] | Prepaid And Other Current Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	20		20		98
Designated as Hedging Instrument [Member] | Other Long Term Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	52		52		65
Designated as Hedging Instrument [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	25		25		3
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	11		11		4
Not Designated as Hedging Instrument [Member] | Prepaid And Other Current Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	24		24		36
Not Designated as Hedging Instrument [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	34		34		$ 19
Not Designated as Hedging Instrument [Member] | Other, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	5	(28)	(12)	(67)
Net gain (loss) from foreign currency transaction exposures	(13)	29	4	63
Foreign Currency Transaction Gain (Loss), Realized	(8)	1	(8)	(4)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(6)	(99)	(64)	(158)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	27	32	56	80
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(6)	(99)	(64)	(158)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 27	$ 32	$ 55	$ 80