Note 9 - Revenue and Revenue Recognition (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Nov. 30, 2024	Nov. 30, 2023	Nov. 30, 2024	Nov. 30, 2023
Revenue from Contract with Customer, Excluding Assessed Tax	$ 12,135,247	$ 15,597,036	$ 25,595,894	$ 33,010,707
Non-US [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 257,000	$ 228,000

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details