Note 2 - Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Number of Wholly Owned Subsidiaries	5
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%
Asset Impairment Charges, Total	$ 0	$ 0
Capitalized Computer Software, Net, Ending Balance	0	427,000
Capitalized Computer Software, Amortization	144,500	36,000
Amortization of Intangible Assets, Total	115,800	46,000
Research and Development Expense, Total	606,618	437,157
Allowance for Doubtful Accounts Receivable, Current, Ending Balance	24,000	2,000
Cash and Cash Equivalents, at Carrying Value, Ending Balance	11,439,361	14,210,909	$ 21,677,186
Cash Equivalents, at Carrying Value, Total	7,500,000	0
Cash, Uninsured Amount	6,920,000	12,198,000
Cargo and Freight [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total	$ 61,200	$ 42,000
Customer Concentration Risk [Member] \| Export Sales [Member]
Concentration Risk, Percentage	9.90%	9.60%
Two Customers [Member] \| Customer Concentration Risk [Member] \| Accounts Receivable [Member]
Concentration Risk, Percentage	42.00%	42.00%
Three Customers [Member] \| Customer Concentration Risk [Member] \| Accounts Receivable [Member]
Concentration Risk, Percentage	60.00%	60.00%
One Customer [Member] \| Customer Concentration Risk [Member] \| Sales Revenue, Net [Member]
Concentration Risk, Percentage	38.20%	66.10%
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life	5 years
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	20 years
Computer Software, Intangible Asset [Member] \| Minimum [Member]
Finite-Lived Intangible Asset, Useful Life	3 years
Computer Software, Intangible Asset [Member] \| Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	5 years

The number of subsidiaries that are 100% owned by the reporting entity.

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Amount of expense for amortization of capitalized computer software costs.

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The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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