Note 10 - Stock Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation expense	$ 1,648	$ 1,271
The 2012 Director Stock Incentive Plan [Member]
Stock-based compensation expense	484	623
The 2012 Omnibus Stock Incentive Plan [Member]
Stock-based compensation expense	479	615
The 2022 Omnibus Stock Incentive Plan [Member]
Stock-based compensation expense	651	1
The 2002 Employee Stock Purchase Plan [Member]
Stock-based compensation expense	$ 34	$ 32