v3.26.1
Note 3 - Summary of Significant Accounting Policies (Details Textual)
 12 Months Ended
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2025
EUR (€)
Accounts Receivable, Allowance for Credit Loss, Current $ 0 $ 0  
Cash, FDIC Insured Amount 117,630    
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down 0 $ 3,300,000  
Asset Retirement Obligation, Discount Rate   7.30%  
Asset Retirement Obligation 0    
Revenue from Contract with Customer, Including Assessed Tax 0 $ 311,000  
Goodwill, Impairment Loss 0 0  
Income Tax Examination, Penalties Accrued 100,000 200,000  
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax 206,000 $ 245,000  
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Continuing Operations [Member]      
Number of Major Customers   1  
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Continuing Operations [Member] | One Customer [Member]      
Revenue from Contract with Customer, Including Assessed Tax $ 0 $ 300,000  
Number of Major Customers   1  
Concentration Risk, Percentage   100.00%  
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Discontinued Operations [Member]      
Number of Major Customers   5  
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Discontinued Operations [Member] | Five Customers [Member]      
Revenue from Contract with Customer, Including Assessed Tax   $ 7,700,000  
Number of Major Customers   5  
Concentration Risk, Percentage   76.00%  
Solar Energy Facilities [Member]      
Property, Plant, and Equipment, Useful Life (Year) 35 years   35 years
Furniture and Fixtures [Member]      
Property, Plant, and Equipment, Useful Life (Year) 3 years   3 years
Computer Equipment [Member] | Minimum [Member]      
Property, Plant, and Equipment, Useful Life (Year) 3 years   3 years
Computer Equipment [Member] | Maximum [Member]      
Property, Plant, and Equipment, Useful Life (Year) 5 years   5 years
European Union [Member]      
Cash, FDIC Insured Amount | €     € 100,000
UNITED STATES      
Cash, FDIC Insured Amount $ 250,000    
Revenue from Contract with Customer, Including Assessed Tax $ 0 $ 311,000