Note 7 - Stock-based Compensation and Equity Transactions - Options Outstanding (Details)	3 Months Ended
	Jan. 31, 2021 $ / shares shares
Outstanding, shares (in shares) | shares	789,179
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 4.66
Options granted, shares (in shares) | shares	67,000
Options granted, weighted average exercise price (in dollars per share) | $ / shares	$ 4.98
Options exercised, shares (in shares) | shares	(118,189)
Options exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 3.26
Options cancelled, shares (in shares) | shares	(91,793)
Options canceled or expired, weighted average exercise price (in dollars per share) | $ / shares	$ 5.88
Options outstanding, shares (in shares) | shares	646,197
Options outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 4.78
Options exercisable, shares (in shares) | shares	298,781
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 4.85
Options vested and expected to vest, shares (in shares) | shares	645,861
Options vested and expected to vest, weighted average exercise price (in dollars per share) | $ / shares	$ 4.78