Note 3 - Basis of Reporting and Significant Accounting Policies (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Allowance for Doubtful Accounts Receivable, Ending Balance	$ 0	$ 0	$ 0	$ 0
Depreciation, Total	$ 321,818	$ 328,980	644,962	659,765
Asset Impairment Charges, Total			$ 0	$ 0
Unrecognized Tax Benefits, Ending Balance					$ 0

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of unrecognized tax benefits.

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