Hedging Activities and Fair Value Measurements (Details) € in Millions, £ in Millions, $ in Millions	3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2020 USD ($) units	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) units	Sep. 30, 2019 USD ($)	Sep. 30, 2019 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)
Derivative Instruments, Gain (Loss) [Line Items]
Payments for Hedge, Investing Activities			$ 0	$ 294
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net			30			$ 34
Derivative, Notional Amount	$ 10,286		10,286			10,218
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(50)	$ 78	36	136
Cost of Goods and Services Sold	869	777	2,465	2,265
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	14	16	52	34
Interest Expense	86	95	265	294
Other Operating Income (Expense), Net	(64)		(9)
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax	(5)	(9)	(14)	(25)
Derivative Asset, Fair Value, Gross Asset	325		325			321
Derivative Liability, Fair Value, Gross Liability	1,116		1,116			1,037
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	0		0			1
Derivative Asset	179		179			216
Licensing arrangements, asset	246		246			332
Business Combination, Contingent Consideration, Liability	214		214			354
Licensing arrangements, liability	262		262			374
Cash	305		305			165
Proceeds from secured borrowings relating to royalty arrangements			256
Debt Instrument, Fair Value Disclosure	10,901		10,901			11,020
November 2019 Aggregate Offering [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt						1,000	€ 900
December 2027 Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt	$ 1,054		$ 1,054			1,011
Debt Instrument, Interest Rate, Stated Percentage	0.625%		0.625%
Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from Royalties Received			$ (132)
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option			9
Licensing arrangement liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments for Royalties			(165)
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option			7
Euro-denominated outstanding debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure	$ 1,050		1,050			1,004
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Licensing arrangements, asset	396		396
Licensing arrangements, liability	413		413
Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Value of Outstanding Net Investment Hedges	1,885		1,885			1,950
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds, at Carrying Value	1,716		1,716			50
Equity Securities, FV-NI	0		0			1
Derivative Asset	325		325			321
Licensing arrangements, asset	396		396			518
Assets, Fair Value Disclosure	2,438		2,438			890
Derivative Liability	1,116		1,116			1,037
Business Combination, Contingent Consideration, Liability	214		214			354
Licensing arrangements, liability	413		413			571
Financial and Nonfinancial Liabilities, Fair Value Disclosure	1,743		1,743			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	1,716		1,716			50
Equity Securities, FV-NI	0		0			1
Derivative Asset	0		0			0
Licensing arrangements, asset	0		0			0
Assets, Fair Value Disclosure	1,717		1,717			51
Derivative Liability	0		0			0
Business Combination, Contingent Consideration, Liability	0		0			0
Licensing arrangements, liability	0		0			0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		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			0
Equity Securities, FV-NI	0		0			0
Derivative Asset	325		325			321
Licensing arrangements, asset	0		0			0
Assets, Fair Value Disclosure	325		325			321
Derivative Liability	1,116		1,116			1,037
Business Combination, Contingent Consideration, Liability	0		0			0
Licensing arrangements, liability	0		0			0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	1,116		1,116			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			0
Equity Securities, FV-NI	0		0			0
Derivative Asset	0		0			0
Licensing arrangements, asset	396		396			518
Assets, Fair Value Disclosure	396		396			518
Derivative Liability	0		0			0
Business Combination, Contingent Consideration, Liability	214		214			354
Licensing arrangements, liability	413		413			571
Financial and Nonfinancial Liabilities, Fair Value Disclosure	627		627			925
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	270		270			288
Derivative Instruments in Hedges, Liabilities, at Fair Value	1,058		1,058			1,009
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	$ 1,042		$ 1,042			998
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Forward Currency Contracts, Time to Maturity | units	60		60
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	$ 90		$ 90			72
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Noncurrent Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	179		179			216
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	6		6			3
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Liabilities, at Fair Value	9		9			8
Not Designated as Hedging Instrument [Member] | Other Nonoperating Income (Expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	29	(202)	20	(334)
Foreign Currency Transaction Gain (Loss), before Tax	(30)	(4)	(33)	0
Net currency exchange gain (loss)	(1)	(207)	(13)	(334)
Not Designated as Hedging Instrument [Member] | BTG Acquisition [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Payments for Hedge, Investing Activities				294
Not Designated as Hedging Instrument [Member] | BTG Acquisition [Member] | Other Nonoperating Income (Expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments		(207)		(323)
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	4,283		4,283			4,377
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	56		56			33
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 58		$ 58			29
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | BTG Acquisition [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Cash Received on Hedge				4,303	£ 3,312
Weighted Average [Member] | Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input	15.00%		15.00%
Weighted Average [Member] | Licensing arrangement liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input	13.00%		13.00%
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%		11.00%
Minimum [Member] | Licensing arrangement liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input	12.00%		12.00%
Maximum [Member] | Licensing arrangement assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input	15.00%		15.00%
Maximum [Member] | Licensing arrangement liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input	15.00%		15.00%
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months	$ 79		$ 79
Cash Flow Hedging [Member] | Interest Rate Contract [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	(5)		(5)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	4,118		4,118			3,891
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	(64)	101	47	176
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	14	(23)	(11)	(40)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(50)	78	36	136
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(20)	(22)	(70)	(47)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	4	5	16	10
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	(15)	(17)	(55)	(36)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	0	0	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	0	0	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	0	0	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	1	1	4	3
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	0	0	(1)	(1)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	1	1	3	2
Net Investment Hedging [Member] | Foreign Exchange Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Used in Net Investment Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	17		17
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	991		991			953
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax	(21)	64	(4)	92
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax	5	(14)	(21)	(21)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, after Tax	(16)	50	(25)	71
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax	(6)	(12)	(18)	(33)
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), after Reclassification, Tax	1	3	4	7
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax	(5)	$ (9)	(14)	$ (25)
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | foreign currency denominated in debt [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	894		894			$ 997
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | foreign currency denominated in debt [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax	(46)		(44)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax	10		13
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, after Tax	(36)		(31)
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax	0		0
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), after Reclassification, Tax	0		0
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax	$ 0		$ 0