Note 12 - Stock Repurchase Program - Schedule of Stock Purchases (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																72 Months Ended	96 Months Ended
	Apr. 30, 2024	[1]	Jan. 31, 2024	[1]	Oct. 31, 2023	[1]	Jul. 31, 2023		Apr. 30, 2023	[1]	Jan. 31, 2023	[1]	Oct. 31, 2022	[1]	Jul. 31, 2022	[1]	Apr. 30, 2022	Apr. 30, 2024
Number of Shares Purchased (in shares)	5,000		24,744		2,300		6,863,789	[1]	2,000		85,307		150		1,639		3,290,426	10,275,355
Average Price Paid per Share (in dollars per share)	$ 0.79		$ 0.73		$ 0.73		$ 0.73	[1]	$ 0.68		$ 0.68		$ 0.7		$ 0.84		$ 0.41	$ 0.63
Number of Shares Purchased as Part of Publicly Announced Plans or Programs (in shares)	5,000		24,744		2,300		6,863,789	[1]	2,000		85,307		150		1,639		3,290,426	10,275,355
Approximate Dollar Value of Shares That May Yet Be Purchased Under the Plan or Programs	$ 2,536		$ 2,540		$ 2,558		$ 2,560	[1]	$ 2,594		$ 2,595		$ 2,653		$ 2,653		$ 2,655	$ 2,536	[1]
Increase in program authorization July 2023							$ 7,594

[1] These shares of common stock were purchased through a private transaction