v2.4.0.6
Acquisition of Pharmasset, Inc. (Narrative) (Details) (USD $)
 3 Months Ended
Mar. 31, 2012
Dec. 31, 2011
Mar. 31, 2011
Jan. 17, 2012
Jan. 13, 2012
Senior Notes Used in Acquisition[Line Items]          
Per share acquisition price       $ 137  
Total cash paid for acquisition $ 11,052,309,000     $ 11,100,000,000  
Acquisition financed with cash on hand       5,200,000,000  
Bank Debt Used in Acquisition       2,200,000,000  
Outstanding Common Stock Acquired         88.00%
Cash Payments to Outstanding Shareholders       10,380,000,000  
Cash Payment to Option Holders       668,300,000  
Payments to Outstanding Common Shareholders Treated as Consideration       474,300,000  
Accelerated Stock-Based Compensation 193,937,000        
IPR&D       10,720,000,000  
Present value discount rate       12.00%  
Goodwill resulting from acquisition 74,817,000     74,817,000  
Other Costs Associated with Acquisition 24,716,000 52,278,000 16,400,000    
Senior Unsecured Notes Due In December Two Thousand Fourteen December Two Thousand Sixteen December Two Thousand Twenty One December Two Thousand Forty One [Member]
          
Senior Notes Used in Acquisition[Line Items]          
Debt Instrument, Face Amount   $ 3,700,000,000   $ 3,700,000,000