Note 16 - Related Party Transactions - Related Party Revenue, Cost of Goods Sold, and Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Total related party revenue	$ 0	$ 0	$ 175	$ 173
Cost of goods sold	0	0	131	90
Total related party expenses	0	160	0	251
Director Bob Wu [Member]
Total related party expenses	0	0	0	50
China Kington [Member]
Total related party expenses	0	160	0	201
China Kington [Member] | The 2019 Foreign Warrants [Member]
Total related party expenses	0	160	0	160
China Kington [Member] | Broker Fee for the Exercise of the June 2019 Warrants [Member]
Total related party expenses	0	0	0	41
NeutroPhase [Member]
Total related party revenue	0	0	175	173
Cost of goods sold	$ 0	$ 0	$ 131	$ 90