Fair Value Measurements (Details) € in Millions, £ in Millions, $ in Millions			12 Months Ended
	Aug. 19, 2019 GBP (£)	Aug. 19, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure				$ 7,239			$ 11,020
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			$ 195	(21)	$ 48
Payments to Acquire Businesses, Net of Cash Acquired			4,382	1,448	560
Available-for-sale Securities				0			1
Licensing arrangements, asset				0			332
Licensing arrangements, liability				0			374
Notional Amount of Interest Rate Derivatives				12,326			10,218
Cash				133			165
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net			34	7
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax			116	96
Cost of Goods and Services Sold			3,116	2,813	2,593
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax			54	(14)
Interest Expense			473	241	229
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax			(33)	(21)
Derivative Asset				183			216
Derivative Instruments in Hedges, Liabilities, at Fair Value				49			1,009
Derivative Liability				80			1,037
Proceeds from secured borrowings relating to royalty arrangements			256	0	0
Proceeds from Royalties Received			52	0	0
Derivative, Notional Amount				12,326			10,218
Net Investment Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			95
Notional Amount of Interest Rate Derivatives							1,950
Derivative, Notional Amount							1,950
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Licensing arrangements, asset				0			518
Licensing arrangements, liability							571
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds, at Carrying Value				13			50
Available-for-sale Securities				0			1
Foreign Currency Contract, Asset, Fair Value Disclosure				304			321
Licensing arrangements, asset							518
Assets, Fair Value Disclosure				318			890
Foreign Currency Contracts, Liability, Fair Value Disclosure				80			1,037
Accrued Contingent Consideration				347			354
Licensing arrangements, liability							571
Liabilities, Fair Value Disclosure				427			1,963
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds, at Carrying Value				13			50
Available-for-sale Securities				0			1
Foreign Currency Contract, Asset, Fair Value Disclosure				0			0
Assets, Fair Value Disclosure				14			51
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]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds, at Carrying Value				0			0
Available-for-sale Securities				0			0
Foreign Currency Contract, Asset, Fair Value Disclosure				304			321
Assets, Fair Value Disclosure				304			321
Foreign Currency Contracts, Liability, Fair Value Disclosure				80			1,037
Accrued Contingent Consideration				0			0
Liabilities, Fair Value Disclosure				80			1,037
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds, at Carrying Value				0			0
Available-for-sale Securities				0			0
Foreign Currency Contract, Asset, Fair Value Disclosure				0			0
Licensing arrangements, asset							518
Assets, Fair Value Disclosure				0			518
Foreign Currency Contracts, Liability, Fair Value Disclosure				0			0
Accrued Contingent Consideration				347			354
Licensing arrangements, liability				0			571
Liabilities, Fair Value Disclosure				347			925
Proposed BTG Acquisition [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	£ 3,312	$ 4,023
derivative, notional amount translated							2,550
BTG Acquisition [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired			3,619
BTG Acquisition [Member] | Accounts Payable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			54
BTG Acquisition [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			567
BTG Acquisition [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			195
BTG Acquisition [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			104
BTG Acquisition [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			212
BTG Acquisition [Member] | Other Noncurrent Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			373
BTG Acquisition [Member] | Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			$ 370
Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted Average Discount Rate, Percent			19.00%
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option			$ 3
Euro-denominated outstanding debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure							1,004
Licensing arrangement liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input			19.00%
Weighted Average Discount Rate, Percent			19.00%
Minimum [Member] | Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input			11.00%
Maximum [Member] | Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input			19.00%
Licensing arrangement liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			$ 315
Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Assets Acquired			567
Tender Offer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt							$ 1,000	€ 900
December 2027 Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage						0.625%	0.625%	0.625%
Long-term Debt				0			$ 1,011
Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value				237			288
Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value				55			72
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value				0			998
Derivative Instruments in Hedges, Liabilities, at Fair Value				3			8
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value				183			216
Designated as Hedging Instrument [Member] | Forward Contracts [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value				2			3
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value				44			0
Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset				304			321
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Derivatives				5,880			4,377
Derivative, Notional Amount				5,880			4,377
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value				67			33
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value				31			29
Not Designated as Hedging Instrument [Member] | BTG Acquisition [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash						£ 3,312	4,303
Not Designated as Hedging Instrument [Member] | Euro Member Countries, Euro
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Loss on Derivative			294
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Derivatives				1,483			953
Derivative, Notional Amount				1,483			953
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | foreign currency denominated in debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Derivatives				0			997
Derivative, Notional Amount				0			997
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Derivatives				3,962			3,891
Derivative, Notional Amount				3,962			3,891
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount of Interest Rate Derivatives				1,000			0
Derivative, Notional Amount				1,000			0
Cost of Sales [Member] | Cash Flow Hedging [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months							77
Cost of Sales [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax			150	167	(101)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax			(34)	(38)	37
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax			117	130	(65)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax			(73)	19	(64)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax			16	(4)	23
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax			(56)	15	(41)
Other Nonoperating Income (Expense) [Member] | Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net			(343)	41	(25)
Net gain (loss) from foreign currency transaction exposures			(15)	(30)	10
Foreign Currency Transaction Gain (Loss), Realized			(358)	11	(15)
Other Nonoperating Income (Expense) [Member] | Not Designated as Hedging Instrument [Member] | BTG Acquisition [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments			(323)	29
Interest Expense [Member] | Net Investment Hedging [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Used in Net Investment Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net							24
Interest Expense [Member] | Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax				(56)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax				13
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax				(43)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax				27
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax				6
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax				(21)
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax			68
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax			(15)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, after Tax			53
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax			(43)
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), after Reclassification, Tax			10
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax			33
Interest Expense [Member] | Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | foreign currency denominated in debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax			(14)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax			3
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, after Tax			(11)
Interest Expense [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net							$ (5)
Interest Expense [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax			0	(44)	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax			0	10	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax			0	(34)	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax			(3)	(1)	1
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax			(1)	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax			$ 2	$ (1)	$ (1)