Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2013	$ 29,867	$ 8,005,708	$ 90,154,528	$ 64,637,173	$ (13,643,986)	$ (1,606,510)	$ 147,576,780
Net income				14,952,537			14,952,537
Amount of loss recognized in other comprehensive income, net of tax					11,708,770		11,708,770
Common cash dividends declared				(631,009)			(631,009)
Preferred cash dividends declared and accrued				(1,081,877)			(1,081,877)
Redemption of Series F Non-cumulative Perpetual Preferred Stock	$ (29,867)		(29,794,055)				(29,823,922)
Proceeds from issuance of common stock, Employee Stock Purchase Plan		25,321	353,566				378,887
Proceeds from issuance of common stock, stock options exercised		23,659	218,095				241,754
Stock-based compensation expense			891,619				891,619
Tax benefit of nonqualified stock options exercised			42,954				42,954
Restricted stock awards - common stock		30,055	(30,055)
Exchange of common stock, restricted stock vested		(10,300)	(167,684)				(177,984)
Balance at Dec. 31, 2014		8,074,443	61,668,968	77,876,824	(1,935,216)	(1,606,510)	144,078,509
Tax basis adjustment related to the acquisition of noncontrolling interest in m2 Lease Funds
Net income				16,927,881			16,927,881
Amount of loss recognized in other comprehensive income, net of tax					(188,613)		(188,613)
Common cash dividends declared				(934,682)			(934,682)
Proceeds from issuance of common stock, Employee Stock Purchase Plan		24,033	375,120				399,153
Proceeds from issuance of common stock, 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
Restricted stock awards - common stock		28,846	(28,846)
Balance at Dec. 31, 2015		11,761,083	123,282,851	92,965,645	(2,123,829)		225,885,750
Proceeds from issuance of common stock, net of issuance costs		3,680,000	59,804,123				63,484,123
Retirement of treasury stock, common stock		(121,246)	(580,886)	(904,378)		$ 1,606,510
Exchange of common stock in connection with stock options exercised and restricted stock vested		(4,631)	(81,595)				(86,226)
Tax basis adjustment related to the acquisition of noncontrolling interest in m2 Lease Funds
Net income				27,686,787			27,686,787
Amount of loss recognized in other comprehensive income, net of tax					(335,760)		(335,760)
Common cash dividends declared				(2,035,531)			(2,035,531)
Proceeds from issuance of common stock, Employee Stock Purchase Plan		20,192	417,336				437,528
Proceeds from issuance of common stock, 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 - common stock		21,882	(21,882)
Balance at Dec. 31, 2016		13,106,845	156,776,642	$ 118,616,901	$ (2,459,589)		286,040,799
Proceeds from issuance of common stock, net of issuance costs		1,215,000	28,613,916				29,828,916
Exchange 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