Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance at Dec. 31, 2015	$ 11,761,083	$ 123,282,851	$ 92,965,645	$ (2,123,829)	$ 225,885,750
Net income			6,373,489		6,373,489
Other comprehensive income, net of tax				2,525,411	2,525,411
Common cash dividends declared			(470,873)		(470,873)
Proceeds from issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan	5,054	94,560			99,614
Proceeds from issuance of common stock, stock options exercised	46,020	729,473			775,493
Stock compensation expense		382,761			382,761
Restricted stock awards - common stock	22,382	(22,382)
Exchange of common stock in connection with stock options exercised and restricted stock vested	(19,628)	(431,806)			(451,434)
Balance at Mar. 31, 2016	11,814,911	124,057,965	98,868,261	401,582	235,142,719
Tax benefit of nonqualified stock options exercised		22,508			22,508
Balance at Dec. 31, 2016	13,106,845	156,776,642	118,616,901	(2,459,589)	286,040,799
Net income			9,184,965		9,184,965
Other comprehensive income, net of tax				410,739	410,739
Common cash dividends declared			(656,574)		(656,574)
Proceeds from issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan	3,573	83,091			86,664
Proceeds from issuance of common stock, stock options exercised	44,284	630,290			674,574
Stock compensation expense		388,753			388,753
Restricted stock awards - common stock	13,289	(13,289)
Exchange of common stock in connection with stock options exercised and restricted stock vested	(6,772)	(283,518)			(290,290)
Balance at Mar. 31, 2017	$ 13,161,219	$ 157,581,969	$ 127,145,292	$ (2,048,850)	$ 295,839,630