Note 8 - Investments, Including Investments Accounted for Using the Equity Method - Reconciliation of the Company's Investments in Equity Affiliates (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Beginning of period			$ 952,128	$ 871,918	$ 871,918
Additional investments in unconsolidated affiliates					66,000
Distributions received			(382,443)		(59,550)
Loss on investment in affiliate			(107,630)
Equity in income of unconsolidated affiliates	$ 101,429	$ 23,464	385,091	$ 15,233	73,760
End of period	$ 847,146		$ 847,146		$ 952,128

Amount of gain (loss) on sale or disposal of an equity method investment.

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Amount of investment in equity method investee and investment in and advance to affiliate.

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