Note 10 - Equity Incentive Plans and Equity - Share Based Compensation Performance Shares Award Outstanding (Details) - Performance Shares [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Balance (in shares) | shares	1,372,819
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 18.31
Granted (in shares) | shares	844,508
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 139.02
Exercised (in shares) | shares	(63,315)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 27.34
Forfeited (in shares) | shares	(35,000)
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 15.65
Balance (in shares) | shares	2,119,012
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 66.19
Balance, average remaining contractual term (Year)	7 years 9 months 18 days
Balance, aggregate instrinsic value | $	$ 161,231
Exercisable (in shares) | shares	1,008,964
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 11.05
Exercisable, average remaining contractual term (Year)	5 years 10 months 24 days
Exercisable, aggregate instrinsic value | $	$ 132,110