Note 6 - Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property and equipment, at cost	$ 711	$ 686
Less: accumulated depreciation and amortization	(611)	(602)
Total property and equipment, net	100	84
Equipment [Member]
Property and equipment, at cost	20	20
Furniture and Fixtures [Member]
Property and equipment, at cost	157	157
Computer Equipment and Software [Member]
Property and equipment, at cost	390	365
Production Equipment [Member]
Property and equipment, at cost	65	65
Leasehold Improvements [Member]
Property and equipment, at cost	$ 79	$ 79

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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