Note 3 - Stock-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2022	Dec. 31, 2021
Outstanding (in shares)		574
Outstanding, weighted average exercise price (in dollars per share)		$ 14.23
Outstanding, weighted average remaining contractual life (Year)		5 years 9 months 18 days	6 years 1 month 6 days
Outstanding, aggregate intrinsic value	[1]	$ 93	$ 100
Granted (in shares)		0
Granted, weighted average exercise price (in dollars per share)		$ 0
Exercised (in shares)		0
Exercised, weighted average exercise price (in dollars per share)		$ 0
Forfeited (in shares)		0
Forfeited, weighted average exercise price (in dollars per share)		$ 0
Outstanding (in shares)		574	574
Outstanding, weighted average exercise price (in dollars per share)		$ 14.23	$ 14.23
Exercisable (in shares)		473
Exercisable, weighted average exercise price (in dollars per share)		$ 14.90
Exercisable, weighted average remaining contractual life (Year)		5 years 6 months
Exercisable, aggregate intrinsic value	[1]	$ 28

[1] Intrinsic value is calculated based on the amount by which the closing market value of the Company’s stock exceeded the exercise price of the underlying options, multiplied by the number of shares.