Note 9 - Intangible Assets, Net (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	June 30, 2021
	Gross		Accumulated			Intangible
	Amount		amortization			assets, net
Patents	$	8,362	$	(4,480	)	$	3,882
Trademarks		22		(16	)		6
Total intangible assets	$	8,384	$	(4,496	)	$	3,888

	December 31, 2020
	Gross		Accumulated			Intangible
	Amount		amortization			assets, net
Patents	$	8,158	$	(4,165	)	$	3,993
Trademarks		21		(15	)		6
Total intangible assets	$	8,179	$	(4,180	)	$	3,999

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

2022	$	609
2023		609
2024		609
2025		609
2026		609
thereafter		843
	$	3,888