v2.4.0.6
Fair value measurements (Details Textual) (USD $)
3 Months Ended 3 Months Ended
Mar. 31, 2013
Dec. 31, 2012
Mar. 31, 2013
BioVex Group Inc [Member]
ContingentConsideration
Mar. 31, 2013
BioVex Group Inc [Member]
Other operating expense [Member]
Mar. 31, 2012
BioVex Group Inc [Member]
Other operating expense [Member]
Mar. 31, 2013
Other Government-related and Corporate Debt Securities [Member]
Business Combinations [Line Items]            
Investment maturity period           5 years
Length of time hedged in foreign currency contracts P3Y          
Maximum additional consideration due contingent on certain milestones     $ 575,000,000      
Maximum number of contingent consideration payments for achieving regulatory and sales related milestones     8      
The number of payments that will potentially be made that each equal the largest potential contingent consideration payment     3      
Largest potential contingent consideration payments     125,000,000      
Change in fair values of contingent consideration obligations       1,000,000 2,000,000  
Fair Value Measurement (Textual) [Abstract]            
Aggregate fair value of long-term debt, including current portion 26,900,000,000 29,900,000,000        
Carrying value of long-term debt, including current portion $ 23,892,000,000 $ 26,529,000,000