XML 63 R50.htm IDEA: XBRL DOCUMENT v3.4.0.3
Warrant Liability - Additional Information (Detail)
 1 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2011
$ / shares
shares
Mar. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2014
USD ($)
shares
Dec. 31, 2013
USD ($)
shares
Dec. 31, 2012
USD ($)
shares
Dec. 31, 2011
USD ($)
$ / shares
$ / Stock_Unit
shares
Apr. 30, 2015
$ / shares
Class of Warrant or Right [Line Items]                
Term of warrant 5 years              
Proceeds from issuance of stock units | $     $ 7,102,225          
Warrant expiration period 2 years              
Dividend yield     0.00%          
Series B Warrants [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by each warrant or right warrants 0.75   0.75          
Exercise price of warrants | $ / shares $ 5.04   $ 5.04          
Number of additional warrants issued 249,709              
Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by each warrant or right warrants 0.50   0.50          
Exercise price of warrants | $ / shares $ 3.60   $ 3.60          
Number of additional warrants issued 166,473              
Proceeds from sale of stock | $       $ 1,652,000 $ 538,000 $ 3,078,000    
Common Stock [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Exercise price of warrants | $ / shares               $ 8.40
December 2011 Financing [Member]                
Class of Warrant or Right [Line Items]                
Proceeds from issuance of common stock and warrants | $             $ 10,000,000  
Price per unit | $ / shares             $ 15.00  
Number of Series A warrants in each unit issued in public offering | $ / Stock_Unit             1  
December 2011 Financing [Member] | Series B Warrants [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by warrants   666,667         666,667  
Term of warrant   90 days         90 days  
Warrant expiration date     May 02, 2012          
Exercise price of warrants | $ / shares   $ 15.00         $ 15.00  
Number of warrants exercised           225,000    
Number of warrants expired     441,667     441,667    
December 2011 Financing [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by warrants   666,667         666,667  
Term of warrant   5 years            
Number of securities callable by each warrant or right warrants 1   1          
Exercise price of warrants | $ / shares $ 3.60   $ 3.60          
Number of warrants exercised       98,335 32,045 183,215    
Number of additional warrants issued           225,000    
Dividend yield     0.00%          
December 2011 Financing [Member] | Capital Units [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by warrants   666,667         666,667  
December 2011 Financing [Member] | Capital Units [Member] | Series B Warrant [Member]                
Class of Warrant or Right [Line Items]                
Warrant expiration period     2016-12          
December 2011 Financing [Member] | Capital Units [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by each warrant or right warrants   1         1  
December 2011 Financing [Member] | Common Stock [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by each warrant or right warrants 1 1 1       1  
Number of shares issued upon warrants exercise           225,000    
December 2011 Financing [Member] | Common Stock [Member] | Series B Warrant [Member]                
Class of Warrant or Right [Line Items]                
Number of shares issued upon warrants exercise           225,000    
December 2011 Financing [Member] | Common Stock [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Exercise price of warrants | $ / shares   $ 16.80         $ 16.80  
Number of shares issued upon warrants exercise       98,335 32,045 183,215    
April 2015 Financing [Member] | Common Stock [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Exercise price of warrants | $ / shares $ 6.24   $ 6.24         $ 8.40
March 2016 Financing [Member] | Series B Warrants [Member]                
Class of Warrant or Right [Line Items]                
Exercise price of warrants | $ / shares 5.04   $ 5.04          
Dividend yield     0.00%          
March 2016 Financing [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Exercise price of warrants | $ / shares 3.60   $ 3.60          
Dividend yield     0.00%          
March 2016 Financing [Member] | Common Stock [Member] | Series A Warrants [Member]                
Class of Warrant or Right [Line Items]                
Exercise price of warrants | $ / shares $ 3.60   $ 3.60          
Underwritten Public Offering [Member]                
Class of Warrant or Right [Line Items]                
Number of shares issued upon warrants exercise 2,222,250              
Proceeds from issuance of stock units | $ $ 8,000,000              
Number of stock units issued, price per share | $ / shares $ 3.60   $ 3.60          
Over-Allotment-Option [Member]                
Class of Warrant or Right [Line Items]                
Number of securities callable by each warrant or right warrants 416,672   416,672          
Number of shares issued upon warrants exercise 333,338              
Underwriting option exercise period 45 days