Note 4 - Summary of Stock Option Activity (Details) - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.17	$ 5.16
Outstanding, Number of Shares (in shares)	68,400	72,400
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.17	$ 5.17
Outstanding, Number of Shares (in shares)	68,400	70,400
Outstanding, Weighted Average Remaining Contractual Term	4 years 361 days	5 years 302 days
Outstanding, Aggregate Intrinsic Value	$ 83,933	$ 86,886
Exercisable, Weighted Average Exercise Price (in dollars per share)			$ 5.17
Exercisable, Number of Shares (in shares)			68,400	70,400
Exercisable, Weighted Average Remaining Contractual Term	4 years 361 days	5 years 302 days
Exercisable, Aggregate Intrinsic Value			$ 83,933	$ 86,886
Exercised, Weighted Average Exercise Price (in dollars per share)		$ (4.96)
Exercised, Number of Shares (in shares)		(2,000)
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.17	$ 5.16	$ 5.17	$ 5.17