v3.19.1
Subsequent Events - Additional Information (Detail) - USD ($)
1 Months Ended
Jan. 09, 2019
Mar. 31, 2019
Dec. 31, 2018
Jun. 01, 2018
Jan. 31, 2018
Dec. 31, 2017
Subsequent Event [Line Items]            
Amount owed by vendor           $ 441,000
Warrants exercisable into shares of common stock       1,183,116 570,287  
Exercise price of warrants, per share     $ 3.73 $ 3.02 $ 9.15  
Strike price per share       $ 3.14    
Subsequent Events [Member] | Settlement Agreement with Vendor [Member]            
Subsequent Event [Line Items]            
Amount owed by vendor $ 164,000          
Issuance of restricted common shares 93,448          
Warrants exercisable into shares of common stock 93,448 382,165        
Exercise price of warrants, per share $ 1.64          
Strike price per share   $ 3.02        
Aggregate proceeds from exercise of warrants   $ 1,154,000