Note 10 - Equity Incentive Plans and Equity - Stock Options Activity (Details) - Service Period Stock Options [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Balance (in shares) | shares	1,359,990
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 11.50
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) | shares	382,910
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 127.89
Exercised (in shares) | shares	(415,499)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 8.97
Forfeited (in shares) | shares	(357)
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 11.00
Balance (in shares) | shares	1,327,044
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 45.88
Balance, average remaining contractual term (Year)	7 years
Balance, aggregate intrinsic value | $	$ 128,778
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares) | shares	874,153
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 10.99
Exercisable, average remaining contractual term (Year)	5 years 8 months 12 days
Exercisable, aggregate intrinsic value | $	$ 115,520