Note 7 - Share-based Compensation - Stock-settled Stock Appreciation Rights Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Lapsed or cancelled (in shares)	(7,572)
Lapsed or cancelled, weighted average exercise price (in dollars per share)	$ 17.89
Stock Appreciation Rights (SARs) [Member]
Outstanding SARS (in shares)	291,059
Outstanding (in dollars per share)	$ 14.99
Outstanding SARS, weighted average remaining life (Year)	2 years 7 months 17 days	2 years 7 months 24 days
Outstanding SARS, aggregate intrinsic value	$ 1,208	$ 2,205
Granted SARs (in shares)	37,297
Granted SARS, weighted average exercise price (in dollars per share)	$ 20.13
Exercised SARs (in shares)	(24,836)
Exercised SARS, weighted average exercise price (in dollars per share)	$ 15.16
Lapsed or cancelled (in shares)	(2,308)
Lapsed or cancelled, weighted average exercise price (in dollars per share)	$ 16.97
Outstanding SARS (in shares)	301,212	291,059
Outstanding SARS, weighted average exercise price (in dollars per share)	$ 15.60	$ 14.99
Exercisable (in shares)	232,228
Exercisable, weighted average exercise price (in dollars per share)	$ 13.48
Exercisable, weighted average remaining life (Year)	2 years 2 months 4 days
Exercisable, aggregate intrinsic value	$ 1,208