Note 10 - Share-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Options on Common Shares, Outstanding (in shares)	3,935,883
Outstanding, weighted average exercise price (in dollars per share)	$ 5.24
Outstanding, remaining contractual term (Year)	6 years 3 months 25 days	4 years 9 months 14 days
Options on Common Shares, Granted (in shares)	2,559,639
Granted, weighted average exercise price (in dollars per share)	$ 2.92
Options on Common Shares, Exercised (in shares)	(50,000)
Exercised, weighted average exercise price (in dollars per share)	$ 1.50
Options on Common Shares, Forfeited, cancelled, expired (in shares)	(757,246)
Forfeited, cancelled, expired, weighted average exercise price (in dollars per share)	$ 7.87
Options on Common Shares, Outstanding (in shares)	5,688,276	3,935,883
Outstanding, weighted average exercise price (in dollars per share)	$ 3.88	$ 5.24
Outstanding June 30, 2022	$ 232,778
Exercisable June 30, 2022 (in shares)	2,351,826
Exercisable weighted average exercise price (in dollars per share)	$ 4.38
Exercisable, remaining contractual term (Year)	2 years 3 months 25 days
Exercisable June 30, 2022	$ 232,778