Note 8 - Line of Credit (Details Textual)	Apr. 28, 2023 USD ($)	Jun. 30, 2023 USD ($)	Apr. 03, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jan. 09, 2019 USD ($)
Cash		$ 23,990,879			$ 21,460,948
Minimum [Member]
Cash	$ 22,000,000
Revolving Credit Agreement, Addendum, and Stand-Alone Revolving Note [Member] | U.S. Bank N.A. [Member]
Line of Credit Facility, Maximum Borrowing Capacity						$ 6,000,000.0
Debt Instrument, Covenant, Current Ratio	6
Long-Term Debt		0
Debt Instrument, Covenant, Minimum Liquid Assets		$ 12,000,000
Debt Instrument, Covenant, Minimum Liquid Assets		3
Revolving Credit Agreement, Addendum, and Stand-Alone Revolving Note [Member] | U.S. Bank N.A. [Member] | Secured Over Night Financing Rate (SOFR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Revolving Credit Agreement, Addendum, and Stand-Alone Revolving Note [Member] | U.S. Bank N.A. [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 10,000,000	$ 12,000,000	$ 10,000,000	$ 10,000,000.0