Quarterly report pursuant to Section 13 or 15(d)

Note 2 - Summary of Significant Accounting Policies (Details Textual)

v3.20.2
Note 2 - Summary of Significant Accounting Policies (Details Textual)
3 Months Ended 6 Months Ended 12 Months Ended
Sep. 18, 2019
USD ($)
Jun. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2019
USD ($)
Mar. 31, 2019
USD ($)
Jun. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
$ / shares
shares
Payments for Fractional Shares of Reverse Stock Split $ 6,000            
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares   $ 0.0001     $ 0.0001   $ 0.0001 [1]
Common Stock, Shares Authorized (in shares) | shares   75,000,000     75,000,000   75,000,000 [1]
Number of Financial Institutions   1     1    
Accounts Receivable, Allowance for Credit Loss, Ending Balance   $ 463,000     $ 463,000   $ 407,000
Accounts Receivable, Allowance for Credit Loss, Writeoff   173,000 $ 0   173,000 $ 0  
Deferred Income   804,000     804,000   662,000
Contract with Customer, Liability, Revenue Recognized   6,000     303,000    
Contract with Customer, Asset, after Allowance for Credit Loss, Total   0     0   0
Contract with Customer, Liability, Total   21,000     21,000   108,000
Capitalized Contract Cost, Net, Total   102,000     102,000   $ 337,000
Capitalized Contract Cost, Impairment Loss   0   $ 0 0    
Capitalized Contract Cost, Amortization   133,000 0   331,000 0  
Equity Method Investment, Other than Temporary Impairment   $ 0 $ 0   $ 0 $ 0  
Series B Preferred Stock [Member]              
Preferred Stock, Shares Outstanding, Ending Balance (in shares) | shares   33,685     33,685   31,678 [1]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares) | shares   22,016,179     22,016,179    
Conversion of Stock Exchange Ratio         653.59    
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares   $ 1,000     $ 1,000    
Conversion of Stock, Conversion Rate (in dollars per share) | $ / shares   $ 1.53     $ 1.53    
Minimum [Member]              
Warranty Period (Year)         1 year    
Maximum [Member]              
Warranty Period (Year)         3 years    
Marketing Programs [Member]              
Contract with Customer, Liability, Revenue Recognized   $ 4,000     $ 87,000    
Contract with Customer, Liability, Total   $ 21,000     $ 21,000   $ 108,000
Customer Concentration Risk [Member] | Revenue Benchmark [Member]              
Concentration Risk, Number of Customers   3 3   1 2  
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Three Customers [Member]              
Concentration Risk, Percentage   74.00% 55.00%        
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | One Customer [Member]              
Concentration Risk, Percentage         49.00%    
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Two Customers [Member]              
Concentration Risk, Percentage           32.00%  
Customer Concentration Risk [Member] | Accounts Receivable [Member]              
Concentration Risk, Number of Customers         1   2
Customer Concentration Risk [Member] | Accounts Receivable [Member] | One Customer [Member]              
Concentration Risk, Percentage         21.00%    
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Two Customers [Member]              
Concentration Risk, Percentage             49.00%
Reverse Stock Split [Member]              
Stockholders' Equity Note, Stock Split, Conversion Ratio 100            
[1] The condensed consolidated balance sheet as of December 31, 2019 has been derived from the audited consolidated financial statements as of that date.