Note 15 - Stock-based Compensation - Summarize Stock Option Activity (Details)	12 Months Ended
	Oct. 31, 2020 $ / shares shares
Options outstanding, Number (in shares) | shares	2,069,398
Options outstanding, Weighted average exercise price (in dollars per share) | $ / shares	$ 1.33
Granted, Number (in shares) | shares	7,250
Granted, Weighted average exercise price (in dollars per share) | $ / shares	$ 0.01
Forfeited, Number (in shares) | shares	(25,888)
Forfeited, Weighted average exercise price (in dollars per share) | $ / shares	$ 0.01
Exercised, Number (in shares) | shares	(27,660)
Exercised, Weighted average exercise price (in dollars per share) | $ / shares	$ 0.01
Expired, Number (in shares) | shares	(500)
Expired, Weighted average exercise price (in dollars per share) | $ / shares	$ 0.01
Modified, Number (in shares) | shares	(231,284)
Modified, Weighted average exercise price (in dollars per share) | $ / shares	$ 0.01
Options outstanding, Number (in shares) | shares	1,791,316
Options outstanding, Weighted average exercise price (in dollars per share) | $ / shares	$ 1.54