Fair Value Measurements Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Cost of Goods and Services Sold	$ 672	$ 650
Interest Expense	61	57
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion	(118)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	27
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net	2,565		$ 2,671
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(91)
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	15
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	12
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(3)
Derivative Assets	32		82
Derivative Liabilities	154		90
Publicly-held Securities	12		15
Foreign Currency Contracts, Liability, Fair Value Disclosure	3,595		3,252
Cash	245		167
Debt Instrument, Fair Value Disclosure	6,040		5,945
Derivative, Notional Amount	6,161		5,923
Fair Value, Measurements, Recurring [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	42		21
Publicly-held Securities	12		15
Foreign Currency Contract, Asset, Fair Value Disclosure	32		82
Assets, Fair Value Disclosure	86		118
Foreign Currency Contracts, Liability, Fair Value Disclosure	154		90
Accrued Contingent Consideration	152		169
Liabilities, Fair Value Disclosure	306		259
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	42		21
Publicly-held Securities	12		15
Foreign Currency Contract, Asset, Fair Value Disclosure	0		0
Assets, Fair Value Disclosure	54		36
Foreign Currency Contracts, Liability, Fair Value Disclosure	0		0
Accrued Contingent Consideration	0		0
Liabilities, Fair Value Disclosure	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
Publicly-held Securities	0		0
Foreign Currency Contract, Asset, Fair Value Disclosure	32		82
Assets, Fair Value Disclosure	32		82
Foreign Currency Contracts, Liability, Fair Value Disclosure	154		90
Accrued Contingent Consideration	0		0
Liabilities, Fair Value Disclosure	154		90
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
Publicly-held Securities	0		0
Foreign Currency Contract, Asset, Fair Value Disclosure	0		0
Assets, Fair Value Disclosure	0		0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0		0
Accrued Contingent Consideration	152		169
Liabilities, Fair Value Disclosure	152		169
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	17		64
Derivative Instruments in Hedges, Liabilities, at Fair Value	123		69
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	3		7
Designated as Hedging Instrument [Member] | Other Long Term Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	15		57
Designated as Hedging Instrument [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	54		37
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	69		33
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	15		18
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	31		$ 21
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	(23)	(17)
Net gain (loss) from foreign currency transaction exposures	16	17
Foreign Currency Transaction Gain (Loss), Realized	(8)	0
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion	(118)	(58)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	27	21
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(91)	(37)
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	15	28
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	12	(18)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(3)	$ 10
Fair Value Hedging [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	12
Cash Flow Hedging [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	1
Cash Flow Hedging [Member] | Cost of Goods, Product Line [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ (55)