Note 13 - Stock-based Compensation - Summary of Outstanding Options (Details) - USD ($)	6 Months Ended
	Jun. 30, 2021
Outstanding (in shares)	2,423,466
Outstanding, weighted average exercise price (in dollars per share)	$ 4.41
Issued (in shares)	55,000
Issued, weighted average exercise price (in dollars per share)	$ 31.22
Exercised (in shares)	(495,733)
Exercised, weighted average exercise price (in dollars per share)	$ 3.42
Expired/Forfeited (in shares)	(6,000)
Expired/Forfeited, weighted average exercise price (in dollars per share)	$ 15.30
Outstanding (in shares)	1,976,733
Outstanding, weighted average exercise price (in dollars per share)	$ 5.38
Outstanding, weighted average remaining contractual life (Year)	1 year 7 months 6 days
Outstanding, aggregate intrinsic value	$ 67,851,195
Exercisable (in shares)	1,541,401
Exercisable, weighted average exercise price (in dollars per share)	$ 3.50
Exercisable, weighted average remaining contractual life (Year)	1 year 1 month 6 days
Exercisable, aggregate intrinsic value	$ 55,805,456