Note 11 - Stockholders' Equity - Summary of Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Outstanding (in shares)	846,754	931,840	1,047,094
Outstanding, weighted average exercise price (in dollars per share)	$ 33.83	$ 28.22	$ 28.22
Outstanding, weighted average contractual term (Year)	4 years 4 months 6 days	4 years 6 months	4 years 5 months 26 days	4 years 3 months 21 days
Outstanding, aggregate intrinsic value	$ 7,878	$ 13,888	$ 11,442	$ 13,367
Granted (in shares)	159,275	151,161	222,110
Granted, weighted average exercise price (in dollars per share)	$ 47.21	$ 48.60	$ 36.67
Exercised (in shares)	(133,963)	(217,121)	(331,958)
Exercised, weighted average exercise price (in dollars per share)	$ 25.80	$ 20.95	$ 17.99
Exercised, aggregate intrinsic value	$ 3,021	$ 6,975	$ 5,413
Canceled / Expired (in shares)	(12,091)	(19,126)	(5,406)
Canceled / Expired (in dollars per share)	$ 35.53	$ 23.18	$ 27.49
Outstanding (in shares)	859,975	846,754	931,840	1,047,094
Outstanding, weighted average exercise price (in dollars per share)	$ 37.53	$ 33.83	$ 28.22	$ 28.22
Exercisable (in shares)	369,593	301,692	274,411
Exercisable, weighted average exercise price (in dollars per share)	$ 32.16	$ 27.40	$ 23.08
Exercisable, weighted average contractual term (Year)	3 years 2 months 1 day	3 years 3 months 18 days	3 years 6 months
Exercisable, aggregate intrinsic value	$ 5,223	$ 6,886	$ 4,781
Expected to vest (in shares)	490,382	545,062	657,429
Expected to vest, weighted average exercise price (in dollars per share)	$ 41.59	$ 37.38	$ 30.37
Expected to vest, weighted average contractual term (Year)	5 years 2 months 23 days	5 years 1 month 28 days	4 years 11 months 4 days