Note 5 - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Employee Stock Option [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	19,461	29,763
Restricted Stock [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	41
Net income	$ 1,520,997	$ 1,444,407
Numerator for basic and diluted earnings per share	$ 1,520,997	$ 1,444,407
Denominator for basic earnings per share – weighted-average shares (in shares)	9,698,951	10,211,333
Effect of dilutive securities (in shares)	19,502	29,763
Denominator for diluted earnings per share – weighted-average shares (in shares)	9,718,453	10,241,096
Basic earnings per share (in dollars per share)	$ 0.16	$ 0.14
Diluted earnings per share (in dollars per share)	$ 0.16	$ 0.14