Note 6 - Share-based Compensation - Stock-settled Stock Appreciation Rights Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Lapsed or cancelled (in shares)	(136,527)
Lapsed or cancelled, weighted average exercise price (in dollars per share)	$ 17.18
Stock Appreciation Rights (SARs) [Member]
Outstanding SARS (in shares)	292,508
Outstanding (in dollars per share)	$ 14.35
Outstanding SARS, weighted average remaining life (Year)	2 years 10 months 20 days	2 years 25 days
Outstanding SARS, aggregate intrinsic value	$ 1,159	$ 506
Granted SARs (in shares)	79,128
Granted SARS, weighted average exercise price (in dollars per share)	$ 13.84
Exercised SARs (in shares)	(17,920)
Exercised SARS, weighted average exercise price (in dollars per share)	$ 8.48
Lapsed or cancelled (in shares)	(54,064)
Lapsed or cancelled, weighted average exercise price (in dollars per share)	$ 21.14
Outstanding SARS (in shares)	299,652	292,508
Outstanding SARS, weighted average exercise price (in dollars per share)	$ 13.34	$ 14.35
Exercisable (in shares)	149,492
Exercisable, weighted average exercise price (in dollars per share)	$ 13.96
Exercisable SARS, weighted average remaining life (Year)	1 year 4 months 28 days
Exercisable, aggregate intrinsic value	$ 587