Quarterly report pursuant to Section 13 or 15(d)

Note 13 - Subsequent Events (Details Textual)

Note 13 - Subsequent Events (Details Textual) - Revolving Credit Facility [Member] - Loan and Security Agreement With Bremer Bank, National Association [Member] - Subsequent Event [Member]
$ in Millions
Apr. 27, 2022
USD ($)
Line of Credit Facility, Maximum Borrowing Capacity $ 40
Debt Instrument, Minimum Interest Rate Required 1.80%
Debt Instrument, Interest Rate During Period 2.50%
Debt Instrument, Covenant, Minimum Debt Service Coverage Ratio 1.20
Debt Instrument, Covenant, Maximum Debt to Cash Flow Ratio 2
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Debt Instrument, Basis Spread on Variable Rate 1.85%