Note 11 - Stockholders' Equity - Outstanding Common Stock Purchase Warrants (Details) - Purchase Warrants Expiring June 18, 2021 [Member]	Dec. 31, 2021 $ / shares shares
Warrants, number of common shares (in shares) | shares	1,391,667
Warrants, exercise price (in dollars per share) | $ / shares	$ 6.00