Note 10 - Stock Repurchase Program - Schedule of Stock Purchases (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended																30 Months Ended	54 Months Ended
	Oct. 31, 2019		Apr. 30, 2019		Oct. 31, 2020	[1]	Jul. 31, 2020	[1]	Apr. 30, 2020	[1]	Jan. 31, 2020	[1]	Oct. 31, 2019	[1]	Jul. 31, 2019	[1]	Apr. 30, 2019	[1]	Jan. 31, 2019	[1]	Oct. 31, 2018	Oct. 31, 2020		Dec. 31, 2016	[2]
Approximate Dollar Value of Shares That May Yet Be Purchased Under the Plan or Programs	$ 3,206	[1]	$ 94	[1]	$ 2,835		$ 2,911		$ 3,019		$ 3,019		$ 3,206		$ 1,526		$ 94		$ 317		$ 381	$ 2,835	[1]	$ 750
Number of Shares Purchased (in shares)					152,915		212,000		25		267,468		206,050		120,821		580,705		186,727		1,359,619	3,086,330
Average Price Paid per Share (in dollars per share)					$ 0.50		$ 0.51		$ 0.41		$ 0.70		$ 0.46		$ 0.35		$ 0.38		$ 0.34		$ 0.27	$ 0.38
Number of Shares Purchased as Part of Publicly Announced Plans or Programs (in shares)					152,915		212,000		25		267,468		206,050		120,821		580,705		186,727		1,359,619	3,086,330
Increase in program authorization, Approximate Dollar Value of Shares That May Yet Be Purchased Under the Plan or Programs	$ 3,301	[3]	$ 1,569	[4]

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

[2] Board of Directors increased program authorization from $500 to $750

[3] Board of Directors increased program authorization from $2,225 to $4,000

[4] Board of Directors increased program authorization from $750 to $2,225