Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation (Details 2)

v2.4.0.8
Stock-based Compensation (Details 2) (Employee Stock Option [Member], USD $)
In Millions, except Share data, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
item
Jun. 30, 2013
Stock award plans        
Number of homogenous groups for purposes of determining fair values of options     3  
Contractual term of the option     10 years  
Weighted-average assumptions relating to options granted        
Risk-free interest rate (as a percent) 2.20% 0.90% 2.10% 0.80%
Expected term (in years) 6 years 8 months 12 days 6 years 6 years 6 months 5 years 6 months
Dividend yield (as a percent) 0.00% 0.00% 0.00% 0.00%
Expected volatility (as a percent) 76.90% 83.80% 75.30% 73.90%
Additional disclosures        
Options granted (in shares)     3,397,275 2,109,941
Grant-date weighted-average fair value (in dollars per share)     $ 2.35 $ 4.00
Total unrecognized compensation cost, net of estimated forfeitures $ 10.5   $ 10.5  
Shares of common stock available for future grant 7,151,106   7,151,106  
Options exercised during the period (in shares)     9,426  
Consultant [Member]
        
Stock award plans        
Contractual term of the option     10 years  
Recipient of Performance Shares [Member]
        
Additional disclosures        
Options granted (in shares)     950,000