Note 6 - Income Per Common Share - Income Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Basic Income Per Common Share	$ 1,541,907	$ 1,418,636	$ 4,074,664	$ 4,286,128
Basic Income Per Common Share (in shares)	4,370,700	4,338,803	4,365,835	4,329,526
Basic Income Per Common Share (in dollars per share)	$ 0.35	$ 0.33	$ 0.93	$ 0.99
Effect of Dilutive Securities (in shares)	56,853	55,216	53,553	56,340
Diluted Income Per Common Share	$ 1,541,907	$ 1,418,635	$ 4,074,664	$ 4,286,128
Diluted Income Per Common Share (in shares)	4,427,553	4,394,019	4,419,388	4,385,866
Diluted Income Per Common Share (in dollars per share)	$ 0.35	$ 0.32	$ 0.92	$ 0.98