Annual report pursuant to Section 13 and 15(d)

Common Stock - Summary of Outstanding Warrants (Detail)

v3.20.4
Common Stock - Summary of Outstanding Warrants (Detail) - $ / shares
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Jun. 19, 2018
Class of Warrant or Right [Line Items]      
Exercise price per Share     $ 80.00
Warrants Issued In September 2017 [Member]      
Class of Warrant or Right [Line Items]      
Total Outstanding and Exercisable 411    
Exercise price per Share $ 699.2000    
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 $ 80.0000 $ 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 $ 62.8900 $ 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 $ 90.0000    
Expiration Date 2025-05    
Warrants Issued in December 2019 [Member]      
Class of Warrant or Right [Line Items]      
Total Outstanding and Exercisable 660,050    
Exercise price per Share $ 6.6000    
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 $ 7.2400    
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 $ 7.3200    
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 $ 7.5900    
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 $ 0.0010    
Expiration Date [1]    
Warrants Issued in December 2020 [Member]      
Class of Warrant or Right [Line Items]      
Total Outstanding and Exercisable 50,000    
Exercise price per Share $ 8.7500    
Expiration Date 2025-12    
[1] The pre-funded warrants do not have an expiration date.