Note 11 - Stock Options and Restricted Stock - Summary of Restricted Stock Options (Details) - Restricted Stock [Member]	6 Months Ended
	Jun. 30, 2021 $ / shares shares
Balance, Restricted shares (in shares) | shares	24,393
Balance, Restricted shares, Weighted average grant date fair value (in dollars per share) | $ / shares	$ 7.32
Granted, Restricted shares (in shares) | shares	165,000
Granted, Restricted shares, Weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.05
Vested, Restricted shares (in shares) | shares	(5,673)
Vested, Restricted shares, Weighted average grant date fair value (in dollars per share) | $ / shares	$ 8.11
Forfeited, Restricted shares (in shares) | shares	(1,223)
Forfeited, Restricted shares, Weighted average grant date fair value (in dollars per share) | $ / shares	$ 9.99
Balance, Restricted shares (in shares) | shares	182,497
Balance, Restricted shares, Weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.61