Fair Value Measurements (Details) € in Millions, £ in Millions, $ in Millions			12 Months Ended
	Aug. 19, 2019 USD ($)	Aug. 19, 2019 GBP (£)	Dec. 31, 2020 USD ($) units	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 EUR (€)
Derivative Instruments, Gain (Loss) [Line Items]
Payments for Hedge, Investing Activities			$ 0	$ 199	$ 0
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net			29	34
Derivative, Notional Amount			11,349	10,218
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax			77	(116)
Cost of Goods and Services Sold			3,465	3,116	2,813
Derivative financial instruments			60	54
Interest Expense			361	473	241
Other Operating Income (Expense), Net			(362)	358
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax			19	33
Foreign exchange (gain) loss			(32)	(358)	11
Derivative Asset, Fair Value, Gross Asset			242	321
Derivative Liability, Fair Value, Gross Liability			1,262	1,037
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI			414	1
Derivative Asset			109	216
Licensing arrangements, asset			218	332
Business Combination, Contingent Consideration, Liability			196	354	347
Cash			150	165
Proceeds from royalty rights transfer			0	256	0
Debt Instrument, Fair Value Disclosure			10,774	11,020
Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Licensing arrangements, liability			253	374
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			$ 1,105	1,011
Debt Instrument, Interest Rate, Stated Percentage			0.625%
Licensing arrangement assets (Member)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate, Fair Value Input			15.00%
Euro-denominated outstanding debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure			$ 1,118	1,004
BTG Acquisition [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from royalty rights transfer			256
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Licensing arrangements, asset			365
Licensing arrangements, liability			407
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds, at Carrying Value			1,584	50
Equity Securities, FV-NI			414	1
Derivative Asset			242	321
Licensing arrangements, asset			365	518
Assets, Fair Value Disclosure			2,605	890
Foreign Currency Contracts, Liability, Fair Value Disclosure			1,262	1,037
Business Combination, Contingent Consideration, Liability			196	354
Licensing arrangements, liability			407	571
Financial and Nonfinancial Liabilities, Fair Value Disclosure			1,865	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			1,584	50
Equity Securities, FV-NI			414	1
Derivative Asset			0	0
Licensing arrangements, asset			0	0
Assets, Fair Value Disclosure			1,998	51
Foreign Currency Contracts, Liability, Fair Value Disclosure			0	0
Business Combination, Contingent Consideration, Liability			0	0
Licensing arrangements, liability			0	0
Financial and Nonfinancial 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
Equity Securities, FV-NI			0	0
Derivative Asset			242	321
Licensing arrangements, asset			0	0
Assets, Fair Value Disclosure			242	321
Foreign Currency Contracts, Liability, Fair Value Disclosure			1,262	1,037
Business Combination, Contingent Consideration, Liability			0	0
Licensing arrangements, liability			0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure			1,262	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
Equity Securities, FV-NI			0	0
Derivative Asset			0	0
Licensing arrangements, asset			365	518
Assets, Fair Value Disclosure			365	518
Foreign Currency Contracts, Liability, Fair Value Disclosure			0	0
Business Combination, Contingent Consideration, Liability			196	354
Licensing arrangements, liability			407	571
Financial and Nonfinancial Liabilities, Fair Value Disclosure			603	925
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Licensing arrangement assets (Member)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Licensing arrangements, asset			365	518	0
Fair Value of Assets Acquired				567
Proceeds from Royalties Received			175	52
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option			22	3
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Licensing arrangement liabilities (Member)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Licensing arrangements, liability			407	571	0
Fair Value of Assets Acquired				315
Proceeds from Royalties Received				256
Payments for Royalties			(186)
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option			22
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value			162	288
Derivative Instruments in Hedges, Liabilities, at Fair Value			1,191	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			$ 1,094	998
Designated as Hedging Instrument [Member] | Foreign Exchange Contract (Member)
Derivative Instruments, Gain (Loss) [Line Items]
Forward Currency Contracts, Time to Maturity | units			60
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			$ 109	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			44	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			54	8
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			53	72
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			73	(343)	41
Foreign Currency Transaction Gain (Loss), before Tax			(105)	(15)	(30)
Foreign exchange (gain) loss			(32)	(358)	11
Net gain (loss) from foreign currency transaction exposures			105	15	30
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				(323)	29
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract (Member)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount			4,946	4,377
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			71	29
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			$ 79	33
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%
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%
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%
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%
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			$ 21
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)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract (Member)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount			4,531	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			99	(150)	(167)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax			(22)	34	38
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax			77	(117)	(130)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax			83	73	(19)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax			19	16	(4)
Derivative financial instruments			(64)	(56)	15
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	(44)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax			0	0	10
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax			0	0	(34)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax			5	3	(1)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax			(1)	(1)	0
Derivative financial instruments			4	2	(1)
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			13
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract (Member)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount			1,004	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			(37)	(68)	(56)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax			8	15	13
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, after Tax			(29)	(53)	(43)
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax			(24)	43	27
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), after Reclassification, Tax			5	10	6
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax			(19)	33	$ 21
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign currency denominated in debt [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount			868	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			(89)	(14)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax			21	3
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, after Tax			(68)	(11)
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