v3.20.4
Acquisitions, Divestitures, Equity-Method Investments, Licensing Arrangements and Collaborative Arrangements - Divestitures (Details)
€ in Millions
 1 Months Ended 3 Months Ended 12 Months Ended
Nov. 16, 2020
USD ($)
Nov. 13, 2020
USD ($)
Jun. 30, 2020
USD ($)
Sep. 30, 2018
USD ($)
Apr. 30, 2018
USD ($)
Dec. 31, 2020
USD ($)
Sep. 30, 2018
USD ($)
Jul. 01, 2018
USD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jun. 30, 2020
EUR (€)
Mar. 31, 2019
USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Principal amount [1]           $ 4,000,000,000     $ 4,000,000,000        
Proceeds from issuance of long-term debt                 5,222,000,000 $ 4,942,000,000 $ 4,974,000,000    
Reduction in retained earnings           (96,770,000,000)     (96,770,000,000) (97,670,000,000)      
Equity securities with readily determinable fair values [2]           567,000,000     567,000,000 705,000,000      
Gain on investments in equity securities [3],[4]                 540,000,000 454,000,000 586,000,000    
Line of Credit [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Line of credit facility, maximum borrowing capacity           332,000,000     332,000,000        
Line of Credit [Member] | Commercial Paper [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Line of credit facility, maximum borrowing capacity           11,000,000,000     11,000,000,000        
Facility Expiring September 2021 [Member] | Line of Credit [Member] | Commercial Paper [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Line of credit facility, maximum borrowing capacity     $ 4,000,000,000.0     4,000,000,000     4,000,000,000        
Senior Notes [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Debt instrument, face amount       $ 5,000,000,000.0     $ 5,000,000,000.0           $ 5,000,000,000.0
Unsecured Debt [Member] | Senior Notes Due 2021 [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Repurchased debt     $ 1,150,000,000                    
Stated interest rate     1.95%                 1.95%  
Unsecured Debt [Member] | Senior Notes Due 2023 [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Repurchased debt     $ 342,000,000                    
Stated interest rate     5.80%                 5.80%  
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | Upjohn Inc [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Separation-related costs                 434,000,000 $ 83,000,000      
Reduction in retained earnings $ 1,900,000,000                        
Cash divested 412,000,000                        
Net increase to accumulated other comprehensive loss 71,000,000                        
Derecognition of net gains on foreign currency translation adjustment 397,000,000                        
Derecognition of actuarial losses net of prior service credits associated with benefit plans $ 326,000,000                        
Disposed of by Sale, Not Discontinued Operations [Member] | Phase 2b Ready AMPA Receptor Potentiator For CIAS [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Cash received for disposition         $ 75,000,000           85,000,000    
Maximum amount of milestone payments to be received         $ 515,000,000                
Viatris [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Nontrade receivables           401,000,000     $ 401,000,000        
Viatris [Member] | Minimum [Member] | Manufacturing and Supply Agreement [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Period of continuing involvement after disposal                 4 years        
Viatris [Member] | Maximum [Member] | Manufacturing and Supply Agreement [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Period of continuing involvement after disposal                 7 years        
Viatris [Member] | Maximum [Member] | Transition Service Agreement [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Period of continuing involvement after disposal                 3 years        
Viatris [Member] | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | Upjohn Inc [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Cash received for disposition   $ 12,000,000,000.0                      
Allogene [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Gain from contribution agreement               $ 50,000,000     50,000,000    
Ownership percentage                 15.70%        
Cerevel [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Gain on investments in equity securities           $ 20,000,000              
Payments to acquire investments                 $ 12,000,000        
Cerevel [Member] | Bain Capital [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Gain on investments in equity securities             343,000,000       $ 343,000,000    
Cerevel [Member] | Bain Capital [Member] | Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations [Member] | Neuroscience Assets [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Assets held for sale       $ 0     $ 0            
Long-term Investments [Member] | Allogene [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Equity securities with readily determinable fair values               $ 127,000,000          
Upjohn Inc and Upjohn Finance B.V. [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Proceeds from issuance of long-term debt     $ 11,400,000,000                    
Upjohn Inc and Upjohn Finance B.V. [Member] | Senior Notes [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Debt instrument, face amount     600,000,000                    
Upjohn Inc [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Principal amount     $ 7,450,000,000                    
Upjohn Finance B.V. [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Principal amount | €                       € 3,600  
Viatris [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Ratio, shares received for each share held   0.124079                      
Noncontrolling interest, ownership percentage by parent 57.00%                        
Viatris [Member] | Mylan [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Ratio, shares received for each share held   1                      
Noncontrolling interest, ownership percentage by noncontrolling owners 43.00%                        
Cerevel Therapeutics [Member] | Cerevel [Member]                          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                          
Ownership percentage       25.00%         21.50%        
[1] May be redeemed by us at any time, in whole, or in part, at varying redemption prices plus accrued and unpaid interest. The weighted-average effective interest rate for the notes at issuance was 2.11%.
[2] As of December 31, 2020 and 2019, includes money market funds primarily invested in U.S. Treasury and government debt.
[3] (b)2020 gains include, among other things, unrealized gains of $405 million related to investments in BioNTech and SpringWorks Therapeutics, Inc. (SpringWorks). 2019 gains included, among other things, unrealized gains of $295 million related to investments in Cortexyme, Inc. and SpringWorks. 2018 gains included unrealized gains on equity securities of $477 million, reflecting the adoption of a new accounting standard in 2018 and were primarily driven by unrealized gains of $466 million related to our investment in Allogene. See Notes 2B and 7B.
[4] Reported in Other (income)/deductions––net. See Note 4.