Note 7 - Share-based Compensation - Stock-settled Stock Appreciation Rights Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Jan. 01, 2022
Lapsed or cancelled (in shares)	(7,252)
Lapsed or cancelled, weighted average exercise price (in dollars per share)	$ 17.85
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 10 months 17 days	2 years 7 months 24 days
Outstanding SARS, aggregate intrinsic value	$ 1,227		$ 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 5 months 4 days
Exercisable, aggregate intrinsic value	$ 1,227