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]	Treasury Stock [Member]	Total
Balance, beginning at Dec. 31, 2014	$ 8,074,443	$ 61,668,968	$ 77,876,824	$ (1,935,216)	$ (1,606,510)	$ 144,078,509
Balance, ending at Mar. 31, 2015	8,113,040	62,149,073	82,054,713	285,649	$ (1,606,510)	150,995,965
Net income			4,177,889			4,177,889
Other comprehensive loss, net of tax				2,220,865		2,220,865
Proceeds from issuance of common stock, Employee Stock Purchase Plan	5,679	82,641				88,320
Proceeds from issuance of common stock, stock options exercised	9,688	94,728				104,416
Stock-based compensation expense		367,775				367,775
Tax benefit of nonqualified stock options exercised		15,651				15,651
Restricted stock awards	26,502	(26,502)
Exchange of common stock, restricted stock vested	(3,272)	(54,188)				(57,460)
Balance, beginning at Dec. 31, 2015	11,761,083	123,282,851	92,965,645	(2,123,829)		225,885,750
Balance, ending at Mar. 31, 2016	11,814,911	124,057,965	98,868,261	401,582		235,142,719
Net income			6,373,489			6,373,489
Other comprehensive loss, net of tax				$ 2,525,411		2,525,411
Common cash dividends declared, $0.04 per share			$ (470,873)			(470,873)
Proceeds from issuance of common stock, Employee Stock Purchase Plan	5,054	94,560				99,614
Proceeds from issuance of common stock, stock options exercised	30,331	382,639				412,970
Stock-based compensation expense		382,761				382,761
Tax benefit of nonqualified stock options exercised		22,508				22,508
Restricted stock awards	22,382	(22,382)
Exchange of common stock, restricted stock vested	$ (3,939)	$ (84,972)				$ (88,911)