v2.4.0.6
Collaborative arrangements Collaborative arrangements (Textuals 2) (Details) (Collaborative Arrangements With Astrazeneca Plc [Member], USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Research and Development Arrangement, Contract to Perform for Others [Line Items]  
Percentage of related development costs for the 2012-2014 period will be funded by partner 65.00%
Other Revenues [Member]
 
Research and Development Arrangement, Contract to Perform for Others [Line Items]  
Milestone payments received 50
Research and Development Expense [Member]
 
Research and Development Arrangement, Contract to Perform for Others [Line Items]  
Cost recoveries 28