XML 87 R74.htm IDEA: XBRL DOCUMENT v3.19.1
Summary of Outstanding Warrants Issued by Company (Detail) - $ / shares
12 Months Ended
Dec. 31, 2018
Feb. 08, 2017
Aug. 13, 2014
Class Of Warrant Or Right [Line Items]      
Number of Shares Issuable Upon Exercise 765,000    
2014 Consultant Warrant      
Class Of Warrant Or Right [Line Items]      
Number of Shares Issuable Upon Exercise 85,000    
Weighted Average Exercise Price $ 10.70   $ 10.70
Issue Date Aug. 13, 2014    
Expiration Date Aug. 13, 2019    
EWB Warrant      
Class Of Warrant Or Right [Line Items]      
Number of Shares Issuable Upon Exercise 40,000    
Weighted Average Exercise Price $ 3.64 $ 3.64  
Issue Date Feb. 08, 2017    
Expiration Date Feb. 08, 2022    
VLL7 and VLL8 Warrants      
Class Of Warrant Or Right [Line Items]      
Number of Shares Issuable Upon Exercise 580,000    
Weighted Average Exercise Price $ 2.00    
Issue Date Feb. 08, 2017    
Expiration Date Feb. 08, 2022    
2017 Consultant Warrant      
Class Of Warrant Or Right [Line Items]      
Number of Shares Issuable Upon Exercise 60,000    
Weighted Average Exercise Price $ 4.60 $ 4.60  
Issue Date Feb. 08, 2017    
Expiration Date Feb. 08, 2019