Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2014	$ 8,074,443	$ 61,668,968	$ 77,876,824	$ (1,935,216)	$ (1,606,510)	$ 144,078,509
Net income			16,927,881			16,927,881
Other comprehensive loss, net of tax				(188,613)		(188,613)
Common cash dividends declared			(934,682)			(934,682)
Issuance of shares of common stock, net of issuance costs	3,680,000	59,804,123				63,484,123
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan	24,033	375,120				399,153
Issuance of shares of common stock as s result of stock options exercised	79,638	1,091,402				1,171,040
Stock-based compensation expense		941,469				941,469
Tax benefit of nonqualified stock options exercised		93,096				93,096
Retirement of treasury stock, 121,246 shares of common stock	(121,246)	(580,886)	(904,378)		1,606,510
Restricted stock awards - shares of common stock	28,846	(28,846)
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested	(4,631)	(81,595)				(86,226)
Balance at Dec. 31, 2015	11,761,083	123,282,851	92,965,645	(2,123,829)		225,885,750
Net income			27,686,787			27,686,787
Other comprehensive loss, net of tax				(335,760)		(335,760)
Common cash dividends declared			(2,035,531)			(2,035,531)
Issuance of shares of common stock, net of issuance costs	1,215,000	28,613,916				29,828,916
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan	20,192	417,336				437,528
Issuance of shares of common stock as s result of stock options exercised	111,423	1,556,823				1,668,246
Stock-based compensation expense		947,174				947,174
Tax benefit of nonqualified stock options exercised		394,149				394,149
Restricted stock awards - shares of common stock	21,882	(21,882)
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested	(22,735)	(546,140)				(568,875)
Tax basis adjustment related to the acquisition of noncontrolling interest in m2 Lease Funds		2,132,415				2,132,415
Balance at Dec. 31, 2016	13,106,845	156,776,642	118,616,901	(2,459,589)		286,040,799
Net income			35,706,507			35,706,507
Other comprehensive loss, net of tax				1,092,153		1,092,153
Common cash dividends declared			(2,664,561)			(2,664,561)
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan	13,318	454,822				468,140
Issuance of shares of common stock as s result of stock options exercised	114,100	1,611,338				1,725,438
Stock-based compensation expense		1,187,036				1,187,036
Restricted stock awards - shares of common stock	28,289	(28,289)
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested	(23,054)	(986,743)				(1,009,797)
Reclassification of certain tax effects from accumulated other comprehensive income			303,814	(303,814)
Issuance of 678,670 shares of common stock as a result of the acquisition of Guaranty Bank & Trust, net of issuance cost	678,670	30,062,744				30,741,414
Balance at Dec. 31, 2017	$ 13,918,168	$ 189,077,550	$ 151,962,661	$ (1,671,250)		$ 353,287,129