v2.4.0.6
Intangible Assets (Narrative) (Details) (USD $)
3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]      
Amortization expense $ 15,800,000 $ 17,400,000  
Indefinite-lived intangible assets 10,986,200,000   266,200,000
IPR&D [Member] | Pharmasset [Member]
     
Acquired Finite-Lived Intangible Assets [Line Items]      
Indefinite-lived intangible assets 10,720,000,000    
IPR&D [Member] | Arresto Biosciences Inc [Member]
     
Acquired Finite-Lived Intangible Assets [Line Items]      
Indefinite-lived intangible assets     117,000,000
IPR&D [Member] | Calistoga Pharmaceuticals Inc [Member]
     
Acquired Finite-Lived Intangible Assets [Line Items]      
Indefinite-lived intangible assets     $ 149,200,000