Note 2 - Revenue and Product Costs - Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Balance	$ 265
Balance	333
Current portion	166	$ 155
Long-term portion	167	$ 110
Customer Deposits [Member]
Balance	43
Additions, net	0
Transfer to revenue	(43)
Balance	0
Current portion	0
Long-term portion	0
Deferred Revenue [Member]
Balance	265
Additions, net	301
Transfer to revenue	(233)
Balance	333
Current portion	166
Long-term portion	$ 167