Note 8 - Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Finished goods, gross	$ 10,566	$ 13,858
Finished goods, reserve	(2,987)	(3,109)
Finished goods, net	7,579	10,749
Raw materials, gross	10,824	11,163
Raw materials, reserve	(2,695)	(3,065)
Raw materials, net	8,129	8,098
Total inventories, gross	21,390	25,021
Total inventories, reserve	(5,682)	(6,174)
Total inventories, net	15,708	18,847
Current Portion, gross	9,931	11,444
Current Portion, reserve	(1,297)	(1,410)
Inventories	8,634	10,034
Long-term portion, gross	11,459	13,577
Long-term portion, reserve	(4,385)	(4,764)
Inventories, net of current portion	$ 7,074	$ 8,813