v3.10.0.1
Basis of Presentation and Significant Accounting Policies - Additional Information (Details)
$ / shares in Units, $ in Millions
3 Months Ended 12 Months Ended 33 Months Ended
Jan. 01, 2018
USD ($)
Accounting_standard
Dec. 22, 2016
USD ($)
Sep. 28, 2016
USD ($)
$ / shares
Jun. 24, 2016
USD ($)
$ / shares
Apr. 08, 2016
USD ($)
Apr. 01, 2018
USD ($)
Dec. 31, 2018
USD ($)
Operating_Segment
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2018
USD ($)
Operating_Segment
Feb. 03, 2017
USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Number of operating segments | Operating_Segment             2     2  
Number of accounting standards adopted | Accounting_standard 11                    
Cash payments for acquisition, net of cash acquired [1]             $ 0 $ 1,000 $ 18,368    
Payments for merger termination costs         $ 150       150    
Unrealized gain on equity securities             477        
Other income/(deductions)—net [2]             (2,116) (1,416) (3,794)    
Decrease in cash, cash equivalents, restricted cash and cash equivalents [1]             205 1,235 1,041    
Accruals for Medicare rebates, Medicaid and related state program rebates, performance-based contract rebates, chargebacks, sales allowances, cash discounts and sales returns             5,426 4,923   $ 5,426  
Advertising expense             3,100 3,100 3,200    
Research and development expenses [2],[3]             8,006 7,683 7,892    
Nonsoftware License Arrangement [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Research and development expenses             197 169 82    
AstraZeneca [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Consideration transferred   $ 1,040                  
Payments to acquire businesses, cash portion   $ 555           605      
Medivation [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Business acquisition, per share in cash (in dollars per share) | $ / shares     $ 81.5                
Payments to acquire businesses, cash portion     $ 14,300                
Cash payments for acquisition, net of cash acquired     $ 13,900                
Anacor [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Business acquisition, per share in cash (in dollars per share) | $ / shares       $ 99.25              
Payments to acquire businesses, cash portion       $ 4,900              
Cash payments for acquisition, net of cash acquired       4,500              
Debt assumed       $ 698              
ICU Medical [Member] | Disposed of by Sale, Not Discontinued Operations [Member] | HIS [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cash received for disposition                     $ 900
Sales Revenue, Product Line [Member] | Top Ten Products [Member] | Product Concentration Risk [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Concentration risk, amount             $ 1,000        
Concentration risk, percentage             51.00%        
Sales Revenue, Product Line [Member] | Top Nine Products [Member] | Product Concentration Risk [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Concentration risk, amount               $ 1,000 $ 1,000    
Concentration risk, percentage               46.00% 43.00%    
Financial Assets and Liabilities [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax $ 462                    
Cumulative effect on retained earnings, net of tax 419                    
Unrealized gain on equity securities             $ 477        
Accounting for Hedging Activities [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Other income/(deductions)—net             107        
Restricted Cash [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Decrease in cash, cash equivalents, restricted cash and cash equivalents             2        
Reclassification From Financing Activities To Operating Activities [Member] | Cash Flow Classification [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Decrease in debt prepayment and extinguishment costs             7        
Reclassification From Operating Activities To Financing Activities [Member] | Cash Flow Classification [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Increase in accreted interest             $ 83        
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Revenues [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax 584         $ 584          
Cumulative effect on retained earnings, net of tax 450                    
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Revenues [Member] | Collaboration Arrangements [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax 500                    
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Revenues [Member] | Collaboration Arrangements, Income From Upfront And Pre-Approval Milestone Payments [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax 394                    
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Revenues [Member] | Collaboration Arrangements, Product Manufacturing [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax 82                    
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Revenues [Member] | Product Rights And Out-Licensing Arrangements [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax 394                    
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Revenues [Member] | Product Shipments [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, before tax 84                    
Retained Earnings [Member] | Income Tax Accounting [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, net of tax (189)                    
Retained Earnings [Member] | Reclassification of Certain Tax Effects from AOCI [Member]                      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                      
Cumulative effect on retained earnings, net of tax $ 495                    
[1] Amounts may not add due to rounding.
[2] Amounts may not add due to rounding.
[3] Exclusive of amortization of intangible assets, except as disclosed in Note 1L. Basis of Presentation and Significant Accounting Policies: Amortization of Intangible Assets, Depreciation and Certain Long-Lived Assets.