Note 15 - Stock-based Compensation - Options Outstanding by Exercise Price Range (Details) - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Options outstanding (in shares)	631,242	588,534	445,144	374,926
Options outstanding, weighted average exercise price (in dollars per share)	$ 74.73
Options outstanding, weighted average remaining contractual life (Year)	3 years 3 months 18 days
Exercise Price Range 1 [Member]
Options outstanding (in shares)	328,137
Options outstanding, exercise price, lower range (in dollars per share)	$ 53.94
Options outstanding, exercise price, upper range (in dollars per share)	69.19
Options outstanding, weighted average exercise price (in dollars per share)	$ 58.82
Options outstanding, weighted average remaining contractual life (Year)	2 years 8 months 12 days
Exercise Price Range 2 [Member]
Options outstanding (in shares)	303,105
Options outstanding, exercise price, lower range (in dollars per share)	$ 71.64
Options outstanding, exercise price, upper range (in dollars per share)	96.03
Options outstanding, weighted average exercise price (in dollars per share)	$ 91.96
Options outstanding, weighted average remaining contractual life (Year)	3 years 10 months 24 days