Convertible Preferred Stock - Additional Information (Detail) - USD ($)
12 Months Ended
May 27, 2015
Dec. 31, 2015
Dec. 31, 2014
Nov. 06, 2015
Dec. 31, 2013
Temporary Equity [Line Items]          
Number of common stock issued upon conversion of convertible instrument   43,500      
Common Stock [Member]          
Temporary Equity [Line Items]          
Number of common stock issued upon conversion of convertible instrument   1,661,030 946,371    
Series A Convertible Preferred Stock [Member]          
Temporary Equity [Line Items]          
Series A Preferred Stock, shares outstanding   0 5,110    
Dividends issued on Preferred Stock 0 105 356    
Fair value of Series A Preferred Stock dividends   $ 172,000 $ 2,399,000    
Conversion of preferred stock into common shares 0 3,215 166    
Preferred stock, accelerated dividend payment date   May 27, 2015      
Number of common stock issued upon conversion of convertible instrument   (3,215) (166)    
Preferred Stock, shares eliminated       15,000  
Series A Preferred Stock, shares authorized   0 15,000    
Series A Preferred Stock, shares issued   0 5,110   7,920
Series A Convertible Preferred Stock [Member] | Common Stock [Member]          
Temporary Equity [Line Items]          
Number of common stock issued upon conversion of convertible instrument   783,740 40,572    
Tang Capital Partners, L.P. ("TCP") [Member]          
Temporary Equity [Line Items]          
Dividend payment terms   On May 22, 2015, the Company entered into an agreement (the “Acceleration and Conversion Agreement”) with Tang Capital Partners, L.P. (“TCP”) pursuant to which the Company and TCP agreed to accelerate the next dividend payment date from June 30, 2015 to no later than May 29, 2015, and upon payment of such dividend immediately convert the dividend shares into common stock. In connection therewith, the dividend payment date was accelerated to May 27, 2015. There were no shares of Series A convertible preferred stock (“Series A Preferred Stock”) outstanding after the completion of the Acceleration and Conversion Agreement.      
Tang Capital Partners, L.P. ("TCP") [Member] | Series A Convertible Preferred Stock [Member]          
Temporary Equity [Line Items]          
Series A Preferred Stock, shares outstanding   0