Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation (Details)

v2.4.0.8
Stock-based Compensation (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Stock-based awards weighted average assumptions [Abstract]          
Dividend yield (in hundredths) 0.00% 0.00% 0.00% 0.00%  
Expected volatility (in hundredths) 92.00% 92.00% 92.00% 92.00%  
Risk free interest rate (in hundredths) 1.43% 0.72% 0.87% 1.05%  
Expected term 5 years 7 months 6 days 5 years 7 months 6 days 5 years 7 months 6 days 5 years 7 months 6 days  
Stock option activity [Roll Forward]          
Options outstanding beginning of period (in shares)     6,788,383    
Granted (in shares)     1,144,403    
Exercised (in shares)     (297,149)    
Forfeited, expired or cancelled (in shares)     129,296    
Options outstanding end of period (in shares) 7,506,341   7,506,341   6,788,383
Options exercisable at end period (in shares) 4,817,306   4,817,306    
Stock options activity, weighted average exercise price [Roll Forward]          
Options outstanding, beginning of period (in dollars per share)     $ 8.99    
Granted (in dollars per share)     $ 3.10    
Exercised (in dollars per share)     $ 1.75    
Forfeited, expired or cancelled (in dollars per share)     $ 17.88    
Options outstanding, end of period (in dollars per share) $ 8.23   $ 8.23   $ 8.99
Options exercisable weighted average exercise price (in dollars per share) $ 11.13   $ 11.13    
Additional Disclosures [Abstract]          
Options outstanding weighted average remaining contractual term beginning of period     7 years 0 months 4 days   7 years 4 months 10 days
Options outstanding weighted average remaining contractual term end of period     7 years 0 months 4 days   7 years 4 months 10 days
Options exercisable weighted average remaining contractual term     6 years 0 months 11 days    
Options outstanding, aggregate intrinsic value at beginning of period     $ 1,531    
Options outstanding, aggregate intrinsic value at end of period 8,262   8,262   1,531
Options exercisable, aggregate intrinsic value 4,050   4,050    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]          
Total stock-based compensation expense 1,227 2,122 3,946 3,368  
Research and Development [Member]
          
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]          
Total stock-based compensation expense 474 1,304 1,904 1,984  
Selling, General and Administrative Expenses [Member]
          
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]          
Total stock-based compensation expense $ 753 $ 818 $ 2,042 $ 1,384  
Stock Options [Member] | Director [Member]
          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period     1 year    
Stock Options [Member] | Employee [Member]
          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period     4 years    
Restricted Stock Units (RSUs) [Member]
          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period     3 years    
Unvested RSU activity [Roll Forward]          
Unvested balance beginning of period (in shares)     1,459,853    
Granted (in shares)     958,385    
Vested (in shares)     (419,760)    
Forfeited (in shares)     45,434    
Unvested balance end of period (in shares) 953,044   953,044    
Unvested RSU activity, weighted average grant date fair value [Roll Forward]          
Unvested balance, beginning of period (in dollars per share)     $ 2.75    
Granted (in dollars per share)     $ 2.96    
Vested (in dollars per share)     $ 2.99    
Forfeited (in dollars per share)     $ 2.29    
Unvested balance, end of period (in dollars per share) $ 2.63   $ 2.63    
Long Term Incentive Plan [Member] | Stock Options [Member]
          
Stock option activity [Roll Forward]          
Granted (in shares)     1,144,403    
Long Term Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
          
Stock option activity [Roll Forward]          
Granted (in shares)     958,385