Note 7 - Selected Balance Sheet Data - Disclosure on Geographic Areas, Long-lived Assets in Individual Foreign Countries by Country (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property, plant and equipment, net	$ 14,240	$ 14,177
UNITED STATES
Property, plant and equipment, net	12,729	12,539
SINGAPORE
Property, plant and equipment, net	1,340	1,460
Geographical Segments, Other [Member]
Property, plant and equipment, net	$ 171	$ 178

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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