Note 9 - Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income tax expense/(benefit) at federal statutory rate [34%]			$ 1,361,450	$ (353,981)
State taxes			7,643
Change in other accruals			101	(108,172)
Difference between tax and book depreciation			91,033	(53,112)
Stock-based compensation			(58,334)	(117,727)
Domestic production activities deduction			(137,178)
Net operating loss carryforward			(6,800)
Provision for 2014 tax return true up				(71,070)
Income tax expense/(benefit)	$ 573,783	$ (500,372)	$ 1,257,915	$ (704,062)