Fair Value Measurements Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Cost of Goods and Services Sold	$ 739	$ 632	$ 1,411	$ 1,282
Interest Expense	57	58	119	115
Derivative Assets	202		202		$ 82
Derivative Liabilities	45		45		90
Available-for-sale Securities	1		1		15
Cash	159		159		167
Cost-method Investments, Aggregate Carrying Amount	82		82		81
Debt Instrument, Fair Value Disclosure	6,702		6,702		5,945
Derivative, Notional Amount	8,295		8,295		5,923
Fair Value, Measurements, Recurring [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	49		49		21
Available-for-sale Securities	1		1		15
Foreign Currency Contract, Asset, Fair Value Disclosure	202		202		82
Assets, Fair Value Disclosure	253		253		118
Foreign Currency Contracts, Liability, Fair Value Disclosure	45		45		90
Accrued Contingent Consideration	279		279		169
Liabilities, Fair Value Disclosure	324		324		259
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Money Market Funds, at Carrying Value	49		49		21
Available-for-sale Securities	1		1		15
Foreign Currency Contract, Asset, Fair Value Disclosure	0		0		0
Assets, Fair Value Disclosure	50		50		36
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	202		202		82
Assets, Fair Value Disclosure	202		202		82
Foreign Currency Contracts, Liability, Fair Value Disclosure	45		45		90
Accrued Contingent Consideration	0		0		0
Liabilities, Fair Value Disclosure	45		45		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		0
Available-for-sale Securities	0		0		0
Foreign Currency Contract, Asset, Fair Value Disclosure	0		0		0
Assets, Fair Value Disclosure	0		0		0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0		0		0
Accrued Contingent Consideration	279		279		169
Liabilities, Fair Value Disclosure	279		279		169
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	139		139		64
Derivative Instruments in Hedges, Liabilities, at Fair Value	19		19		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	24		24		7
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	94		94		57
Designated as Hedging Instrument [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	9		9		37
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	10		10		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	64		64		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	26		26		21
Not Designated as Hedging Instrument [Member] | Other, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	32	5	8	(12)
Foreign Currency Transaction Gain (Loss), before Tax	(33)	(13)	(17)	4
Net currency exchange gain (loss)	(1)	(8)	(9)	(8)
Net Investment Hedging [Member] | Other Noncurrent Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	21		21
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	(215)	6	97	64
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	48	(2)	22	(23)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(167)	4	76	41
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	(3)	(27)	(18)	(56)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(2)	17	(14)	35
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(1)	10	(4)	21
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	2,635		2,635		2,671
Foreign Exchange Forward [Member] | Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	1,455		1,455		0
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	4,205		4,205		$ 3,252
Net Investment 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	41		41
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		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		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	11		11
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	21		21	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(5)		(5)	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	16		16	0
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	(7)		(7)	(1)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	5		5	1
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	2		2	0
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	194	(6)	77	(64)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(44)	2	(17)	23
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	151	(4)	59	(41)
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	(10)	(27)	(25)	(55)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(7)	17	(19)	34
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	$ (2)	$ 10	$ (6)	$ 21