Quarterly report pursuant to Section 13 or 15(d)

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

v3.23.2
Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)
 6 Months Ended
Jan. 18, 2022
Jun. 30, 2023
Jun. 30, 2022
Mar. 31, 2023
Jan. 01, 2023
Dec. 31, 2022
Mar. 31, 2022
Dec. 31, 2021
Proceeds from Issuance of Common Stock   $ 0 $ 49,440,000          
Retained Earnings (Accumulated Deficit)   45,056,000       $ 45,291,000    
Financing Receivable, Allowance for Credit Loss   1,010,000 $ 769,000 $ 979,000 $ 624,000 624,000 $ 785,000 $ 779,000
Off-Balance-Sheet, Credit Loss, Liability   $ 5,000     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