Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Common Stock - Issued and Outstanding Shares - Additional Information (Detail) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended 34 Months Ended
Apr. 28, 2020
Dec. 17, 2019
Jun. 07, 2019
May 30, 2019
May 22, 2018
Sep. 14, 2017
Mar. 31, 2020
Jun. 30, 2020
Jun. 30, 2019
Mar. 31, 2019
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Common stock, par value               $ 0.001     $ 0.001   $ 0.001 $ 0.001
Common stock, shares issued               1,937,703     1,937,703   1,937,703 1,474,258
Preferred stock, par value               $ 0.001     $ 0.001   $ 0.001  
Proceeds from exercise of warrants, net of issuance costs       $ 4,200,000             $ 589,000 $ 4,199,000    
Stock option exercises, Shares               0 0   0 0    
Restricted stock unit settlements               0 6   0 6    
Common Stock [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock unit settlements                   4        
December 2019 Public Offering [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Exercise price per unit of warrant   $ 6.60                        
Offering expenses                     $ 34,000      
Warrant exercisable period   5 years                        
Cancellation of warrant description                     Additionally, subject to certain exceptions, if, after December 17, 2019, (i) the volume weighted average price of the common stock for each of 30 consecutive trading days, or the 2019 Measurement Period, which 2019 Measurement Period commences on the closing date, exceeds 300% of the exercise price (subject to adjustments for stock splits, recapitalizations, stock dividends and similar transactions), (ii) the average daily trading volume for such 2019 Measurement Period exceeds $500,000 per trading day and (iii) certain other equity conditions are met, and subject to a beneficial ownership limitation, then the Company may call for cancellation of all or any portion of the warrants then outstanding.      
Number of required consecutive days weighted average trading price for cancelation or recall of warrants   30 days                        
Minimum required trading price percentage over exercise price for cancelation or recall of warrants   300.00%                        
Minimum required trading volume value per day for cancelation or recall of warrants   $ 500,000                        
Gross proceeds from sale of warrants and units                     $ 13,800,000      
Warrant and units offering cost including underwriting discounts and commissions                     1,500,000      
Net proceeds from issuance of warrants and units                     $ 12,300,000      
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, net of issuance costs $ 1,600,000                          
Percentage of exercise price exceeds in measurement period                     300.00%      
Average daily trading volume for measurement period                     $ 500,000      
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                          
Percentage of cash commission in gross proceeds from sale of units 9.00%                          
Warrants to purchase common stock 25,270                          
April 2020 Private Placement [Member] | Common Stock [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Common stock, shares issued               280,782            
Series A Convertible Preferred Stock [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Preferred stock, par value               $ 0.001     $ 0.001   $ 0.001 $ 0.001
Preferred stock, shares outstanding               0     0   0 0
Series B Convertible Preferred Stock [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Preferred stock, par value               $ 0.001     $ 0.001   $ 0.001 $ 0.001
Preferred stock, shares outstanding               0     0   0 1,121
Series B Convertible Preferred Stock [Member] | December 2019 Public Offering [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Preferred stock, shares converted                     6,256      
Preferred stock, shares outstanding               0     0   0  
Series B Convertible Preferred Stock [Member] | December 2019 Public Offering [Member] | Common Stock [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Convertible preferred stock, shares issued upon conversion                     521,124      
Maximum [Member] | December 2019 Public Offering [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Exercise price per unit of warrant   $ 1.20                        
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   $ 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   $ 7.32  
Class A Units [Member] | December 2019 Public Offering [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Issuance of new units in a public offering   478,875                        
Public offering, price per unit   $ 12.00                        
Description of stock units issued                     Each Class A Unit consisted of one share of our common stock and a warrant to purchase one share of common stock.      
Class B Units [Member] | December 2019 Public Offering [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Issuance of new units in a public offering   6,256                        
Public offering, price per unit   $ 999.60                        
Description of stock units issued                     Each Class B Unit consisted of one share of Series B Convertible Preferred Stock, par value $0.001 per share, convertible at any time at the holder’s option into approximately 83 shares of common stock, and warrants to purchase approximately 83 shares of common stock.      
Number of common shares issuable for each share of convertible preferred stock   83                        
Number of common shares issuable conversion of warrants   83                        
Warrants to purchase common stock   83                        
Class B Units [Member] | Series A Convertible Preferred Stock [Member] | December 2019 Public Offering [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Preferred stock, par value   $ 0.001                        
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     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   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                
Offering expenses                     $ 14,000      
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                
H.C. Wainwright [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Common stock, par value     $ 0.001                      
Common stock available for sale under offering               $ 6,000,000     $ 6,000,000   $ 6,000,000  
Percentage of commission on gross proceeds from sale of common stock     3.00%                      
H.C. Wainwright [Member] | Maximum [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Common stock value right to sell, maximum     $ 6,000,000                      
Ladenburg Thalmann & Co. Inc [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Period granted for underwriting option   45 days                        
Ladenburg Thalmann & Co. Inc [Member] | 2019 Overallotment Option [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Additional purchase of common stock and warrants, maximum   150,000                        
Overallotment option exercise date   Dec. 17, 2019