Note 11 - Share-based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2020 $ / shares shares
Options on Common Shares, Outstanding (in shares) | shares	3,931,586
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 4.41
Outstanding, remaining contractual term (Year)	5 years 5 months 19 days	4 years 9 months 18 days
Options on Common Shares, Granted (in shares) | shares	982,500
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 5.57
Options on Common Shares, Exercised (in shares) | shares	(915,404)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 1.83
Options on Common Shares, Forfeited, cancelled, expired (in shares) | shares	(319,799)
Forfeited, cancelled, expired, weighted average exercise price (in dollars per share) | $ / shares	$ 5.12
Options on Common Shares, Outstanding (in shares) | shares	3,678,883	3,931,586
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 5.30	$ 4.41
Outstanding, aggregate intrinsic value | $	$ 4,335
Options on Common Shares, Exercisable (in shares) | shares	1,904,711
Exercisable weighted average exercise price (in dollars per share) | $ / shares	$ 4.37
Exercisable, remaining contractual term (Year)	3 years 3 days
Exercisable, aggregate intrinsic value | $	$ 3,493