Note 9 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2020
Unrecognized Tax Benefits	$ 612	$ 768	$ 587	$ 820
Deferred Tax Assets, Valuation Allowance, Total	1,628		1,702
Deferred Tax Assets, Operating Loss Carryforwards	1,027		942
Deferred Tax Assets, Capital Loss Carryforwards	462		462
Foreign Tax Authority [Member] | AUSTRALIA
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (100)	$ 100
Deferred Tax Assets, Operating Loss Carryforwards			1,200
Deferred Tax Assets, Capital Loss Carryforwards			1,500
Foreign Tax Authority [Member] | FRANCE
Deferred Tax Assets, Operating Loss Carryforwards			1,700
Foreign Tax Authority [Member] | SPAIN
Deferred Tax Assets, Operating Loss Carryforwards			500
Foreign Tax Authority [Member] | NORWAY
Deferred Tax Assets, Operating Loss Carryforwards			100
Foreign Tax Authority [Member] | CHINA
Deferred Tax Assets, Operating Loss Carryforwards			400
State and Local Jurisdiction [Member]
Tax Credit Carryforward, Amount			$ 1,700