Quarterly report pursuant to Section 13 or 15(d)

Collaboration Arrangements - Additional Information (Detail)

v2.4.0.6
Collaboration Arrangements - Additional Information (Detail) (Agreements with Merck KGaA [Member], USD $)
In Millions, unless otherwise specified
 3 Months Ended 12 Months Ended 14 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Dec. 31, 2012
Mar. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Upfront payment received     $ 25  
Milestone payments received to date 42.5     72.5
Merck's percentage share of worldwide development expenses 70.00% 70.00% 70.00%  
Portion of profits that Company is eligible to participate in United States, depending upon total sales 50.00% 50.00% 50.00%  
Revenue recognized by the Company 2.9 0.3    
Milestone payments achieved and received 30.0     97.5
Company earned a reimbursement for eligible worldwide development expenses 3.5 1.1    
Regulatory and development milestones [Member]
        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Potential future milestones 112.5      
Regulatory and development milestones [Member] | 2013 Potential Milestone payments [Member]
        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Potential future milestones 12.5      
Commercialization milestones [Member]
        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Potential future milestones $ 340.0