Note 3 - Stock-based Compensation - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) $ / shares shares		Dec. 31, 2021 USD ($) $ / shares shares
Outstanding (in shares) | shares	574
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 14.23
Outstanding, weighted average remaining contractual life (Year)	5 years 7 months 6 days		6 years 1 month 6 days
Outstanding, aggregate intrinsic value | $	$ 70	[1]	$ 100	[1]
Granted (in shares) | shares	0
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Exercised (in shares) | shares	(1)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 4.07
Forfeited (in shares) | shares	(1)
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 4.07
Outstanding (in shares) | shares	572		574
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 14.23		$ 14.23
Exercisable (in shares) | shares	519
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 14.89
Exercisable, weighted average remaining contractual life (Year)	5 years 4 months 24 days
Exercisable, aggregate intrinsic value | $	$ 25	[1]

[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.