Note 10 - Equity Incentive Plans and Equity - Nonvested Performance Based Units Activity (Details) - Performance Stock Options [Member]	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Balance (in shares) | shares	1,338,361
Balance, weighted average grant date fair value (in dollars per share) | $ / shares	$ 10.89
Granted (in shares) | shares	844,508
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 70.83
Vested (in shares) | shares	(1,037,823)
Vested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 6.97
Forfeited (in shares) | shares	(35,000)
Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares	$ 7.49
Balance (in shares) | shares	1,110,046
Balance, weighted average grant date fair value (in dollars per share) | $ / shares	$ 60.25