Note 9 - Intangible Assets, Net - Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Intangible assets, gross amount	$ 8,823	$ 8,632
Intangible assets, accumulated amortization	(5,060)	(4,796)
Intangible assets, net	3,763	3,836
Patents [Member]
Intangible assets, gross amount	8,781	8,597
Intangible assets, accumulated amortization	(5,041)	(4,779)
Intangible assets, net	3,740	3,818
Trademarks [Member]
Intangible assets, gross amount	42	35
Intangible assets, accumulated amortization	(19)	(17)
Intangible assets, net	$ 23	$ 18