Note 11 - CVD Materials Update (Details Textual) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 8,695	$ 4,656
Net Income (Loss) Attributable to Parent	(40)	(997)
Assets	34,784	$ 32,007		$ 37,912
Liabilities	5,217			$ 8,513
Tantaline A/S of Nordborg [Member] | Forecast [Member] | Maximum [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			$ 500,000,000
Tantaline A/S of Nordborg [Member]
Revenue from Contract with Customer, Including Assessed Tax	400
Net Income (Loss) Attributable to Parent	100
Assets	1,100
Liabilities	$ 200