Note 1 - Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Accumulated Depreciation	$ (29,539)	$ (27,700)
Property and Equipment, Net	$ 9,581	10,178
Building [Member] \| Maximum [Member]
Estimated useful lives (Year)	39 years
Land [Member]
Property and equipment	$ 360	360
Leasehold Improvements [Member] \| Maximum [Member]
Estimated useful lives (Year)	15 years
Leasehold Improvements [Member] \| Minimum [Member]
Estimated useful lives (Year)	3 years
Building and Leasehold Improvements [Member]
Property and equipment	$ 9,660	9,184
Manufacturing Equipment [Member]
Property and equipment	$ 21,908	21,260
Manufacturing Equipment [Member] \| Maximum [Member]
Estimated useful lives (Year)	7 years
Manufacturing Equipment [Member] \| Minimum [Member]
Estimated useful lives (Year)	3 years
Office and Other Equipment [Member]
Property and equipment	$ 7,192	$ 7,074
Office and Other Equipment [Member] \| Maximum [Member]
Estimated useful lives (Year)	7 years
Office and Other Equipment [Member] \| Minimum [Member]
Estimated useful lives (Year)	3 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business 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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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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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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