Note 1 - Summary of Significant Accounting Policies - Finite Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021		Dec. 31, 2020
Beginning balance		$ 1,173	[1]	$ 1,338
Additions		50		20
Amortization	$ (45)	(139)		(185)
Abandonment Loss		(560)
Ending balance	524	524		1,173	[1]
Customer Relationships [Member]
Beginning balance		507		651
Additions		0		0
Amortization		(109)		(144)
Abandonment Loss		0
Ending balance	398	398		507
Trade Names [Member]
Beginning balance		590		631
Additions		0		0
Amortization		(30)		(41)
Abandonment Loss		(560)
Ending balance	0	0		590
Patents [Member]
Beginning balance		76		56
Additions		50		20
Amortization		0		0
Abandonment Loss		0
Ending balance	$ 126	$ 126		$ 76

[1] The balance sheet at December 31, 2020 has been derived from the audited financial statements at that date