Warrants (Details) (USD $)
3 Months Ended 12 Months Ended
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2014
Sep. 30, 2012
Nov. 30, 2012
Jul. 02, 2013
Jun. 30, 2014
Warrants                  
(Loss)/gain recognized for change in the fair value of the warrant liability $ (2,545,000) $ (42,000) $ (2,587,000) $ 32,000          
Warrant                  
Warrants                  
Exercise price (in dollars per share)         $ 7.23        
Number of shares of common stock to be purchased against outstanding warrants         285,920        
Warrant | Total | Short term convertible notes issued September 2012                  
Warrants                  
Estimated fair value           100,000      
Warrant | Total | Short term convertible notes issued November 2012                  
Warrants                  
Estimated fair value             200,000    
Series A preferred stock warrant                  
Warrants                  
Warrants exercisable into stock (in shares)               1,940,000  
Exercise price (in dollars per share)               $ 1.00  
Number of shares of common stock to be purchased against outstanding warrants         277,690        
Series A preferred stock warrant | Total | Short term convertible notes issued September and November 2012                  
Warrants                  
Estimated fair value             300,000    
Common stock                  
Warrants                  
Exercise price (in dollars per share)                 $ 15.19
Common stock | Warrant                  
Warrants                  
Warrants exercisable into stock (in shares)               277,690 8,230
Fair value of warrants                 $ 100,000
Share price of common stock (in dollars per share)               $ 6.99