Note 8 - 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, 2021 USD ($) $ / shares shares
Balance (in shares) | shares	2,119
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 66.19
Granted (in shares) | shares	101
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 154.83
Exercised (in shares) | shares	(153)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 9.82
Forfeited (in shares) | shares	0
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Balance (in shares) | shares	2,067
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 74.71
Balance, average remaining contractual term (Year)	7 years 25 days
Balance, aggregate instrinsic value | $	$ 87,896
Exercisable (in shares) | shares	975
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 14.03
Exercisable, average remaining contractual term (Year)	5 years 1 month 6 days
Exercisable, aggregate instrinsic value | $	$ 80,020