Subsequent Events - Additional Information (Detail)
$ in Thousands
1 Months Ended 6 Months Ended 12 Months Ended
Apr. 14, 2016
Jun. 02, 2015
USD ($)
Aug. 11, 2016
USD ($)
shares
Jun. 30, 2015
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
shares
Subsequent Event [Line Items]            
Proceeds from issuance of common stock | $   $ 9,200   $ 9,254 $ 9,266 $ 1,886
Reverse stock split ratio 0.1          
Lincoln Park Capital Fund, LLC [Member]            
Subsequent Event [Line Items]            
Number of common stock sold | shares           50,000
Subsequent Events [Member] | Lincoln Park Capital Fund, LLC [Member]            
Subsequent Event [Line Items]            
Number of common stock sold | shares     35,000      
Proceeds from issuance of common stock | $     $ 82