Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Outstanding Warrants (Detail)

v3.19.1
Common Stock - Summary of Outstanding Warrants (Detail) - $ / shares
 3 Months Ended
Mar. 31, 2019
Jun. 19, 2018
Class of Warrant or Right [Line Items]    
Exercise price per Share   $ 4.00
Series A Warrants [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 25,272  
Exercise price per Share $ 440.00  
Expiration Date 2019-07  
Series B Warrants [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 6,093  
Exercise price per Share $ 440.00  
Expiration Date 2019-07  
Series A-1 Warrants [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 2,175  
Exercise price per Share $ 264.00  
Expiration Date 2020-10  
Warrants Issued In September 2017 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 8,224  
Exercise price per Share $ 34.96  
Expiration Date 2023-03  
Warrants Issued In June 2018 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 3,119,500  
Exercise price per Share $ 4.00  
Expiration Date 2023-06  
Warrants Issued in October 2018 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 894,626  
Exercise price per Share $ 3.14  
Expiration Date 2023-10