Note 17 - Stock-Based Compensation - Stock Option Plans (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock-Based Compensation
Outstanding, shares (in shares)	346,678	367,998	407,763
Outstanding, Weighted average exercise price (in dollars per share)	$ 27.60	$ 24.46	$ 22.24
Granted, shares (in shares)	25,000	22,400	22,150
Granted, Weighted average exercise price (in dollars per share)	$ 53.31	$ 53.87	$ 43.61
Exercised, shares (in shares)	(81,354)	(41,695)	(60,317)
Exercised, Weighted average exercise price (in dollars per share)	$ 19.45	$ 14.07	$ 15.76
Forfeited, shares (in shares)	(175)	(2,025)	(1,598)
Forfeited, Weighted average exercise price (in dollars per share)	$ 15.65	$ 26.72	$ 38.50
Outstanding, shares (in shares)	290,149	346,678	367,998
Outstanding, Weighted average exercise price (in dollars per share)	$ 32.11	$ 27.60	$ 24.46
Exercisable, , shares (in shares)	233,967	295,077	318,266
Weighted-average grant date fair value (in dollars per share)	$ 16.36	$ 13.97	$ 10.85