Quarterly report pursuant to Section 13 or 15(d)

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

v3.21.2
Note 2 - Summary of Significant Accounting Policies (Details Textual)
1 Months Ended 3 Months Ended 6 Months Ended 19 Months Ended 20 Months Ended
Jul. 29, 2021
USD ($)
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
Jul. 29, 2021
USD ($)
Dec. 31, 2020
USD ($)
Number of Operating Segments       1        
Number of Geographic Segments       1        
Revenue from Contract with Customer, Excluding Assessed Tax, Total   $ 0 $ 0 $ 0 $ 18,000      
Percentage of Revenue From Products Transferred at Point in Time         100.00%      
Accounts Receivable, after Allowance for Credit Loss, Current, Total   290,000   290,000   $ 290,000   $ 32,000
Proceeds from Insurance Settlement, Investing Activities       0 $ 7,625,000      
AquaRefining Fire [Member]                
Proceeds from Insurance Settlement, Investing Activities   1,400,000       25,000,000.0    
AquaRefining Fire [Member] | Subsequent Event [Member]                
Proceeds from Insurance Settlement, Investing Activities $ 5,250,000           $ 30,250,000  
Trade Accounts Receivable [Member]                
Accounts Receivable, after Allowance for Credit Loss, Current, Total   $ 0   $ 0   $ 0   $ 0