Quarterly report pursuant to Section 13 or 15(d)

Note 11 - Common Stock (Details Textual)

v3.21.2
Note 11 - Common Stock (Details Textual) - USD ($)
1 Months Ended 2 Months Ended 3 Months Ended 6 Months Ended
May 04, 2021
Jan. 19, 2021
Jun. 09, 2020
Jun. 08, 2020
Apr. 16, 2020
Mar. 31, 2021
Feb. 28, 2021
Jun. 30, 2020
Mar. 31, 2020
Feb. 29, 2020
Mar. 31, 2021
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Jan. 31, 2021
Jan. 18, 2021
Dec. 31, 2020
[1]
Apr. 20, 2020
May 22, 2017
Proceeds from Issuance of Common Stock                           $ 25,122,000 $ 0          
Proceeds from Warrant Exercises                           $ 179,000 4,800,000          
Stock Issued During Period, Share, Restricted Common Shares (in shares)               3,453 2,832         0            
Stock Issued During Period, Value, Restricted Common Shares               $ 25,000 $ 24,000       $ 25,000              
Amortization of Debt Discount (Premium)                       $ 1,000 1,000 $ 2,000 2,000          
Debt Instrument, Unamortized Discount, Total                       7,000   7,000            
Fair Value Adjustment of Warrants                       $ 86,000 $ 1,838,000 $ 373,000 $ 1,838,000          
Class of Warrant or Right Number of Securities Called by Warrants or Rights Cancelled In Period (in shares)                       0 0 0 0          
Class Of Warrant Or Right, Number Of Securities Called By Warrants Or Rights Expired In Period (in shares)                       6 22 6 22          
Series C Preferred Stock [Member]                                        
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           0         0 0   0       0    
Warrants Issued in Connection with January 2021 Offering [Member]                                        
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)                               1        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)                               $ 3.40        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)   8,117,640       8,104,880         8,104,880 8,104,880   8,104,880   8,117,640        
Stock Issued During Period, Shares, Warrant Exercises (in shares)                     12,760                  
Proceeds from Warrant Exercises                     $ 43,000                  
May 2017 Issuance Related to 2017 Loan Agreement [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)                                       $ 9,500.00
Warrants and Rights Outstanding, Term (Year)                                       10 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                       223
Series A Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                       0   0            
Stock Issued During Period, Shares, Warrant Exercises (in shares)         482,059         102,626                    
Proceeds from Warrant Exercises                   $ 1,591,000                    
Series B Warrants [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 3.40                             $ 6.10      
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                       285,632   285,632            
Stock Issued During Period, Shares, Warrant Exercises (in shares)         24,279   40,000     4,548                    
Proceeds from Warrant Exercises             $ 136,000     $ 70,000                    
Series A-2 and Series B-2 Warrants [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 3.40                             $ 6.371   $ 6.371  
Warrants and Rights Outstanding, Term (Year)                                     5 years  
Fair Value Adjustment of Warrants   $ 287,000                                    
Series B, A-2 and B-2 Warrants [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) $ 2.817                                      
Fair Value Adjustment of Warrants $ 86,000                                      
January 2021 Offering Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                       8,104,880   8,104,880            
Stock Issued During Period, Shares, Warrant Exercises (in shares)           4,000 8,760                          
Proceeds from Warrant Exercises           $ 13,000 $ 30,000                          
Series A-2 Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                       392,830   392,830         482,059  
Stock Issued During Period, Shares, Warrant Exercises (in shares)                           392,830            
Series B-2 Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                       20,380   20,380         24,279  
Stock Issued During Period, Shares, Warrant Exercises (in shares)                           20,380            
Class A Units [Member] | Warrants Issued in Connection with Class A Units [Member]                                        
Warrants Per Unit (in shares)   1                                    
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)   1                                    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 3.40                                    
Warrants and Rights Outstanding, Term (Year)   5 years                                    
Class B Units [Member] | Warrants Issued in Connection with Class B Units [Member]                                        
Warrants Per Unit (in shares)   1                                    
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)   1                                    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 3.40                                    
Warrants and Rights Outstanding, Term (Year)   5 years                                    
Purchase Agreement with LPC [Member]                                        
Maximum Amount of Shares Issuable       $ 10,000,000                                
Stock Purchase Agreement Duration Period (Month)       30 months                                
Stock Purchase Agreement, Maximum Issuable Shares (in shares)       301,762                                
Stock Purchase Agreement, Maximum Issuable Shares, Percent of Outstanding Stock       19.99%                                
Stock Purchase Agreement, Share Price Covenant Trigger (in dollars per share)       $ 6.46                                
Stock Issued During Period, Shares, New Issues (in shares) 250,000   52,500                                  
Shares Issued, Price Per Share (in dollars per share) $ 2.817   $ 6.50                                  
Proceeds from Issuance of Common Stock $ 704,000   $ 341,000                                  
Equity Facility, Remaining Financing Commitment                       $ 9,000,000   $ 9,000,000            
First Amendment to the LPC Purchase Agreement [Member]                                        
Stock Purchase Agreement, Maximum Issuable Shares (in shares)           2,068,342         2,068,342                  
Stock Purchase Agreement, Maximum Issuable Shares, Percent of Outstanding Stock           19.99%         19.99%                  
Stock Purchase Agreement, Share Price Covenant Trigger (in dollars per share)           $ 2.99         $ 2.99                  
Stock Issued During Period, Shares, New Issues (in shares) 250,000                                      
Shares Issued, Price Per Share (in dollars per share) $ 2.817                                      
Proceeds from Issuance of Common Stock $ 704,000                                      
January 2021 Offering [Member]                                        
Shares Issued, Price Per Share (in dollars per share)   $ 3.40                                    
Proceeds from Issuance or Sale of Equity, Total   $ 27,600,000                                    
Proceeds from Issuance or Sale of Equity, Net of Issuance Costs   $ 25,122,000                                    
January 2021 Offering [Member] | Series C Preferred Stock [Member]                                        
Stock Issued During Period, Shares, New Issues (in shares)   2,450,880                                    
January 2021 Offering [Member] | Class A Units [Member]                                        
Shares Issued, Price Per Share (in dollars per share)   $ 3.40                                    
Units Issued, Shares (in shares)   4,607,940                                    
Common Shares Per Unit (in shares)   1                                    
Warrants Per Unit (in shares)   1                                    
January 2021 Offering [Member] | Class B Units [Member]                                        
Shares Issued, Price Per Share (in dollars per share)   $ 3.40                                    
Units Issued, Shares (in shares)   2,450,880                                    
Common Shares Per Unit (in shares)   1                                    
Warrants Per Unit (in shares)   1                                    
Over-Allotment Option [Member]                                        
Stock Issued During Period, Shares, New Issues (in shares)   1,058,820                                    
Over-Allotment Option [Member] | Warrants Issued in Connection with January 2021 Offering [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)   1,058,820                                    
[1] The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited consolidated financial statements as of that date.