Note 1 - Accounting Policies (Details Textual)	6 Months Ended
Jun. 30, 2018 USD ($)	Jan. 01, 2018 USD ($)
Contract with Customer, Liability, Total	$ 367,568
Number of Reportable Segments	1
Number of Operating Segments	6
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ (367,568)

Amount of cumulative effect of the change in accounting principle or new accounting pronouncement on retained earnings or other components of equity or net assets in the statement of financial position as of the beginning of the earliest period presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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