Note 6 - Goodwill and Acquisition-related Intangible Assets, Net - Acquisition-related Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Gross Amount	$ 7,484	$ 7,484
Accumulated Amortization	(7,373)	(6,533)
Net Amount	111	951
Know-How [Member]
Gross Amount	1,018	1,018
Accumulated Amortization	(907)	(704)
Net Amount	111	314
Developed Technology Rights [Member]
Gross Amount	6,466	6,466
Accumulated Amortization	(6,466)	(5,829)
Net Amount		$ 637