Note 3 - Basis of Reporting and Significant Accounting Policies (Details Textual) - USD ($)	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Allowance for Doubtful Accounts Receivable, Ending Balance	$ 0	$ 0
Depreciation, Total	323,144	330,785
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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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount of unrecognized tax benefits.

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