Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Outstanding Warrants (Detail)

v3.20.2
Common Stock - Summary of Outstanding Warrants (Detail) - $ / shares
 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Series A-1 Warrants [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 108  
Exercise price per Share $ 5,280.000  
Expiration Date 2020-10  
Warrants Issued In September 2017 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 411  
Exercise price per Share $ 699.200  
Expiration Date 2023-03  
Warrants Issued in June 2018 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 114,100  
Exercise price per Share $ 80.000 $ 80.00
Expiration Date 2023-06  
Warrants Issued in October 2018 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 31,215  
Exercise price per Share $ 62.890 $ 62.89
Expiration Date 2023-10  
Warrants Issued in May 2019 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 60,000  
Exercise price per Share $ 90.000  
Expiration Date 2025-05  
Warrants Issued in December 2019 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 682,871  
Exercise price per Share $ 6.600  
Expiration Date 2024-12  
Warrants Issued in April 2020 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 182,461  
Exercise price per Share $ 7.240  
Expiration Date 2025-04  
Warrants Issued in April 2020 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 28,125  
Exercise price per Share $ 7.320  
Expiration Date 2025-04  
Warrants Issued in April 2020 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 25,270  
Exercise price per Share $ 7.590  
Expiration Date 2025-04  
Pre-Funded Warrants Issued in August 2020 [Member]    
Class of Warrant or Right [Line Items]    
Total Outstanding and Exercisable 142,857  
Exercise price per Share $ 0.001  
Expiration Date [1]  
[1] The pre-funded warrants do not have an expiration date.