v3.19.3.a.u2
Acquisitions, Divestitures, Equity-Method Investments and Assets and Liabilities Held for Sale, Licensing Arrangements and Research and Development and Collaborative Arrangements - R & D and Collaborative Arrangements (Detail) - USD ($)
 1 Months Ended 3 Months Ended 12 Months Ended
Apr. 30, 2016
Jan. 31, 2016
Apr. 01, 2018
Apr. 02, 2017
Dec. 31, 2014
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2013
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Research and development expenses           $ 8,650,000,000 $ 8,006,000,000 $ 7,683,000,000  
Revenues           51,750,000,000 53,647,000,000 52,546,000,000  
Cost of sales           (10,219,000,000) (11,248,000,000) (11,228,000,000)  
Selling, informational and administrative expenses           (14,350,000,000) (14,455,000,000) (14,804,000,000)  
Other income/(deductions)—net           (3,578,000,000) (2,116,000,000) (1,416,000,000)  
NovaQuest Co-Investment Fund V, L.P. [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Maximum funding amount $ 200,000,000                
Percentage of costs to be reimbursed 100.00%                
Reduction to research and development expense           24,000,000 58,000,000 72,000,000  
Charge primarily for inventory manufactured for expected future sale           99,000,000      
Research and development expenses           15,000,000      
RPI Finance Trust [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Maximum funding amount   $ 300,000,000              
Percentage of costs to be reimbursed   100.00%              
Reduction to research and development expense           63,000,000 99,000,000 76,000,000  
Research and development, contingent payments, maximum exposure   $ 250,000,000              
Collaborative Arrangement [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Research and development expenses           99,000,000 162,000,000 222,000,000  
Revenues           5,313,000,000 4,409,000,000 3,533,000,000  
Cost of sales           (351,000,000) (296,000,000) (329,000,000)  
Selling, informational and administrative expenses           (173,000,000) (90,000,000) (54,000,000)  
Other income/(deductions)—net           362,000,000 281,000,000 249,000,000  
Upfront payments and milestone payments             50,000,000 15,000,000  
Collaborative Arrangement [Member] | Eli Lilly & Company [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Proceeds received from upfront payments and milestone payments           67,000,000 98,000,000 147,000,000  
Deferred milestone revenue recognized           9,000,000      
Collaborative Arrangement [Member] | Merck KGaA [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Collaborative arrangement sales based milestones payments           80,000,000   140,000,000  
Potential milestone payments         $ 2,000,000,000.0        
Collaborative Arrangement [Member] | Mylan [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Proceeds received from upfront payments and milestone payments           $ 78,000,000      
Collaborative Arrangement [Member] | Merck [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Proceeds received from upfront payments and milestone payments             40,000,000 150,000,000  
Collaborator's revenue and expense ownership percentage           60.00%      
Company's revenue and expense ownership percentage           40.00%      
Collaborative Arrangement [Member] | Merck [Member] | Other Nonoperating Income (Expense) [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Proceeds received from upfront payments and milestone payments       $ 90,000,000     40,000,000    
Milestone payment due to be received     $ 40,000,000         60,000,000  
Deferred milestone revenue recognized     90,000,000            
Collaborative Arrangement [Member] | Other Noncurrent Liabilities [Member] | Merck [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Deferred milestone payment               60,000,000  
Collaborative Arrangement [Member] | Deferred Revenue [Member] | Eli Lilly & Company [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Proceeds received from upfront payments and milestone payments                 $ 200,000,000
Collaborative Arrangement, Upfront Cash Payment [Member] | Merck KGaA [Member] | Research and Development Expense [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Upfront payments and milestone payments         $ 850,000,000        
Revenues [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Collaborative Arrangement [Member] | Merck [Member] | Other Nonoperating Income (Expense) [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Deferred milestone revenue recognized     85,000,000            
Revenues [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Collaborative Arrangement [Member] | Other Noncurrent Liabilities [Member] | Merck [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Deferred milestone payment     60,000,000            
Revenues [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Collaborative Arrangement [Member] | Deferred Revenue [Member] | Eli Lilly & Company [Member]                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Deferred milestone revenue recognized     $ 107,000,000            
Product [Member] | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Revenues           $ 664,000,000 571,000,000 606,000,000  
Co-promotion [Member] | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Revenues           $ 4,648,000,000 $ 3,838,000,000 $ 2,927,000,000