Quarterly report pursuant to Section 13 or 15(d)

Convertible Preferred Stock - Additional Information (Detail)

v3.2.0.727
Convertible Preferred Stock - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Apr. 28, 2015
Mar. 13, 2014
Jan. 31, 2014
Dec. 11, 2013
Jul. 31, 2006
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
May. 31, 2014
May. 07, 2014
Temporary Equity [Line Items]                        
IPO proceeds that triggers conversion of preferred stock   $ 20,000,000                    
Number of outstanding shares of convertible preferred stock converted into common stock                       1,691,884
Outstanding Series C-1 Preferred warrants           14,033   14,033   14,033    
Exercise price of warrants                     $ 0.20  
Other (expense) income related to fair value adjustment of long term derivative liability             $ 7,297,000   $ 10,442,000      
Proceeds from sale of preferred stock               $ 0 544,000      
Stock issuance costs $ 3,388,000                      
Excess of fair value of warrants over proceeds             0   362,000      
Series C-1 Convertible Preferred Stock [Member]                        
Temporary Equity [Line Items]                        
Outstanding Series C-1 Preferred warrants         196,923              
Exercise price of warrants         $ 3.25              
Warrant expiration date               May 07, 2019        
Fair value of warrants         $ 459,000              
Other (expense) income related to fair value adjustment of long term derivative liability           $ 0 $ 0 $ 0 $ 37,000      
Common Stock [Member]                        
Temporary Equity [Line Items]                        
Outstanding Series C-1 Preferred warrants         14,033              
Exercise price of warrants         $ 45.61              
Series D-2 Preferred [Member]                        
Temporary Equity [Line Items]                        
Outstanding Series C-1 Preferred warrants     19,048 87,532                
Exercise price of warrants     $ 0.20 $ 0.20                
Fair value of warrants     $ 906,000 $ 4,214,000                
Convertible preferred stock, shares     388,641 1,785,712                
Convertible preferred stock, price per share     $ 1.40 $ 1.40                
Proceeds from sale of preferred stock     $ 544,000 $ 2,500,000                
Stock issuance costs       95,000                
Excess of fair value of warrants over proceeds     $ 362,000 $ 1,714,000