Note 14 - Equity Incentive Plan - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Outstanding, shares (in shares)	896,819
Outstanding, Weighted Average Exercise (in dollars per share)	$ 41.50
Granted, shares (in shares)	529,505
Granted, Weighted Average Exercise Price (in dollars per share)	$ 38.08	$ 38.20	$ 34.02
Exercised, shares (in shares)	(31,466)
Exercised, Weighted Average Exercise Price (in dollars per share)	$ 34.58
Exercised, Aggregate Intrinsic Value	$ 257
Forfeited and canceled, shares (in shares)	(218,865)
Forfeited and canceled, Weighted Average Exercise Price (in dollars per share)	$ 44.77
Outstanding, shares (in shares)	1,175,993	896,819
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 39.56
Outstanding, Weighted Average Remaining Contractual Term (Year)	8 years 4 months 24 days
Outstanding, Aggregate Intrinsic Value	$ 975	$ 2,800	$ 8,500
Vested, shares (in shares)	299,451
Vested, Weighted Average Exercise Price (in dollars per share)	$ 43.64
Vested, Weighted Average Remaining Contractual Term (Year)	7 years 2 months 12 days
Vested, Aggregate Intrinsic Value	$ 264
Vested and expected to vest, shares (in shares)	1,175,993
Vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$ 39.56
Vested and expected to vest, Weighted Average Remaining Contractual Term (Year)	8 years 4 months 24 days
Vested and expected to vest, Aggregate Intrinsic Value	$ 975