Note 6 - Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Finished goods, gross	$ 11,318	$ 10,566
Finished goods, reserve	(3,061)	(2,987)
Finished goods, net	8,257	7,579
Raw materials, gross	10,811	10,824
Raw materials, reserve	(2,440)	(2,695)
Raw materials, net	8,371	8,129
Total inventories, gross	22,129	21,390
Total inventories, reserve	(5,501)	(5,682)
Total inventories, net	16,628	15,708
Current Portion, gross	10,468	9,931
Current Portion, reserve	(1,327)	(1,297)
Inventories	9,141	8,634
Long-term portion, gross	11,661	11,459
Long-term portion, reserve	(4,174)	(4,385)
Inventories, net of current portion	$ 7,487	$ 7,074