Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Issued and Outstanding Shares - Additional Information (Detail)

v3.21.1
Common Stock - Issued and Outstanding Shares - Additional Information (Detail) - USD ($)
 3 Months Ended 43 Months Ended
Dec. 07, 2020
Aug. 03, 2020
Jul. 02, 2020
Apr. 28, 2020
Mar. 12, 2020
May 22, 2018
Sep. 14, 2017
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2021
Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, par value               $ 0.001   $ 0.001 $ 0.001
Common stock, shares issued               6,149,917   6,149,917 6,111,735
Proceeds from exercise of warrants               $ 236,000      
Stock option exercises, Shares               0 0    
Restricted stock unit settlements               0 0    
Common Stock [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, shares issued               2,965      
April 2020 Private Placement [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, shares issued       280,782              
Warrants to purchase shares of common stock       0.75              
Warrants to purchase shares of common stock, offering price per share       $ 6.60              
Gross proceeds from issuance of common stock       $ 1,900,000              
Proceeds from exercise of warrants       $ 1,600,000              
Percentage of exercise price exceeds in measurement period               300.00%      
Average daily trading volume for measurement period               $ 500,000      
Number of required consecutive days weighted average trading price for cancelation or recall of warrants               30 days      
April 2020 Private Placement [Member] | Placement Agent [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Exercise price per unit of warrant       $ 7.59              
Number of common shares issuable conversion of warrants       25,270              
Direct Offering [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Gross proceeds from issuance of common stock     $ 6,000,000                
Placement agent fees and offering expenses     700,000                
Proceeds from issuance of common stock     $ 5,300,000                
Direct Offering [Member] | Common Stock [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, shares issued     731,707                
Common stock, price per share     $ 8.20                
August 2020 Public Offering [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Gross proceeds from issuance of common stock   $ 7,500,000                  
Proceeds from issuance of common stock   6,800,000                  
Underwriting discounts and commissions and offering expenses   $ 700,000                  
August 2020 Public Offering [Member] | Common Stock [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, shares issued   569,043                  
Common stock, price per share   $ 10.50                  
Underwriters Over-Allotment Option Exercise [Member] | Common Stock [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, shares issued 322,500 92,856                  
December 2020 Public Offering [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Gross proceeds from issuance of common stock $ 17,300,000                    
Proceeds from issuance of common stock 15,800,000                    
Underwriting discounts and commissions and offering expenses $ 1,500,000                    
December 2020 Public Offering [Member] | Common Stock [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, shares issued 2,472,500                    
Common stock, price per share $ 7.00                    
December 2020 Public Offering [Member] | Representative's Warrant [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Number of common shares issuable conversion of warrants 50,000                    
Common stock, price per share $ 8.75                    
Adjustments to additional paid in capital Other $ 300,000                    
Warrant exercisable term 5 years                    
Subscription Agreements Executed on April 27, 2020 [Member] | April 2020 Private Placement [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Exercise price per unit of warrant               $ 7.24   $ 7.24  
Subscription Agreements Executed on April 28, 2020 [Member] | April 2020 Private Placement [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Exercise price per unit of warrant               $ 7.32   $ 7.32  
Pre-Funded Warrant [Member] | August 2020 Public Offering [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Number of common shares issuable conversion of warrants   142,857                  
Pre-funded warrant, offering price per share   $ 10.499                  
Pre-Funded Warrant [Member] | August 2020 Public Offering [Member] | Common Stock [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Exercise price per unit of warrant   $ 0.001                  
Number of days of prior notice to achieve not in excess percentage of common stock shares owned by warrant holder   61 days                  
Pre-Funded Warrant [Member] | August 2020 Public Offering [Member] | Common Stock [Member] | Minimum [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Percentage of shares of common stock owned by warrant holder   9.99%                  
Pre-Funded Warrant [Member] | August 2020 Public Offering [Member] | Common Stock [Member] | Maximum [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Percentage of shares of common stock owned by warrant holder   19.99%                  
LPC [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock value right to sell, maximum         $ 11,000,000            
Common stock, par value         $ 0.001            
Minimum percentage of common stock shares outstanding authorized to sell           20.00%          
Initial purchase of common stock                   1,644  
Common stock, shares issued             617        
Payments related to expense reimbursement         $ 100,000            
Common stock, shares issued               0   27,868  
Gross proceeds                   $ 4,400,000  
Offering expenses                   500,000  
Common stock available for sale under offering               $ 6,600,000   $ 6,600,000  
LPC [Member] | Purchase Agreement [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Common stock, purchase price             $ 1.00        
Additional common stock value right to sell, maximum             $ 10,000,000        
Additional purchase of common stock, maximum             7,500        
LPC [Member] | Units [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Initial purchase of common stock             1,644        
Common stock, purchase price             $ 608.00        
Purchase agreement, description               Unit consisting of (a) one share of our common stock and (b) one warrant to purchase one-quarter of a share of common stock at an exercise price of $699.20 per share, or Warrant. Each Warrant became exercisable six months following the issuance date until the date that is five years and six months after the issuance date and is subject to customary adjustments.      
Exercise price per unit of warrant             $ 699.20        
Initial purchase of units consisting of common stock and warrants issued             $ 1,000,000        
LPC [Member] | Other Units [Member]                      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                      
Number of warrants issued             0