XML 50 R44.htm IDEA: XBRL DOCUMENT v2.4.0.6
Summary of Significant Accounting Policies - Net Loss per Share (Details)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect      
Total 37,889,521 36,084,880 20,459,334
Options to purchase common stock [Member]
      
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect      
Total 16,257,444 14,302,803 12,649,968
Warrants to purchase common stock [Member]
      
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect      
Total 21,593,844 21,743,844 7,771,133
Convertible preferred stock [Member]
      
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect      
Total 38,233 38,233 38,233