Note 10 - Common Stock and Stock-based Compensation Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2023	Dec. 31, 2022
Outstanding, Number of shares (in shares)	[1],[2]	106,000
Outstanding, Weighted average exercise price (in dollars per share)		$ 20.24
Outstanding, Weighted average remaining contractual term (Year)		1 year 9 months 18 days	2 years
Outstanding, Aggregated intrinsic value		$ 1,080	$ 609
Outstanding, Number of shares (in shares)		106,000	106,000	[1],[2]
Outstanding, Weighted average exercise price (in dollars per share)		$ 20.24	$ 20.24
Exercisable, Number of shares (in shares)	[2]	106,000
Exercisable, Weighted average exercise price (in dollars per share)		$ 20.24
Exercisable, Weighted average remaining contractual term (Year)		1 year 9 months 18 days
Exercisable, Aggregated intrinsic value		$ 1,080

[1] Represent options granted to non-employee directors of the Company only. As of December 31, 2022, there were no outstanding or exercisable SAR units left and no outstanding or exercisable options granted to employees left.

[2] The SAR units are convertible for a maximum number of shares of the Company’s common stock equal to 75% of the SAR units subject to the grant.