Quarterly report pursuant to Section 13 or 15(d)

Note 1 - Summary of Significant Accounting Policies (Details Textual)

v3.23.1
Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)
 3 Months Ended
Jan. 18, 2022
Mar. 31, 2023
Mar. 31, 2022
Jan. 01, 2023
Dec. 31, 2022
Dec. 31, 2021
Proceeds from Issuance of Common Stock   $ 0 $ 49,440,000      
Retained Earnings (Accumulated Deficit)   45,182,000     $ 45,291,000  
Financing Receivable, Allowance for Credit Loss   979,000 $ 785,000 $ 624,000 624,000 $ 779,000
Off-Balance-Sheet, Credit Loss, Liability   $ 6,000   0    
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]            
Retained Earnings (Accumulated Deficit)       (279,000)    
Financing Receivable, Allowance for Credit Loss       384,000 $ 384,000  
Off-Balance-Sheet, Credit Loss, Liability       $ 5,000    
Subscription Offering [Member]            
Stock Issued During Period, Shares, New Issues (in shares) 5,290,000          
Shares Issued, Price Per Share (in dollars per share) $ 10.00          
Proceeds from Issuance of Common Stock $ 53,000,000.0          
Subscription Offering [Member] | NSTS Charitable Foundation [Member]            
Payments of Charitable Contributions $ 150,000          
Subscription Offering [Member] | NSTS Charitable Foundation [Member] | Contribution of Nonmonetary Assets to Charitable Organization [Member]            
Stock Issued During Period, Shares, New Issues (in shares) 107,959