Note 5 - Property and Equipment, Net - Property and Equipment (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment	$ 5,609,000	$ 5,227,000
Less: Accumulated depreciation and amortization	(3,948,000)	(3,155,000)
Property, Plant and Equipment, Net, Ending Balance	1,661,000	2,078,000
Software Development [Member]
Property and Equipment	122,000	124,000
Computer Equipment [Member]
Property and Equipment	144,000	197,000
Machinery and Equipment [Member]
Property and Equipment	1,878,000	1,784,000
Furniture and Fixtures [Member]
Property and Equipment	78,000	78,000
Leasehold Improvements [Member]
Property and Equipment	311,000	326,000
Assets Leased to Others [Member]
Property and Equipment	3,076,000	2,718,000
Property, Plant and Equipment, Net, Ending Balance	1,200,000	1,400,000
Construction in Progress [Member]
Property and Equipment		$ 6,000

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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