Note 9 - Shareholder Rights Plan (Details Textual)	Oct. 12, 2020 $ / shares
Shareholder Rights Plan, Trigger, Beneficial Owner of Outstanding Common Shares, Percentage	15.00%
Shareholder Rights Plan, Exercise Price (in dollars per share)	$ 15
Shareholder Rights Plan, Exercise Input, Percentage of Fair Value of Common Stock	25.00%
Shareholder Rights Plan, Trigger, Assets or Earning Power Sold, Percentage	50.00%
Shareholder Rights Plan, Redemption Price (in dollars per share)	$ 0.001