CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net income	$ 30,786,772	$ 22,663,831	$ 58,752,036	$ 44,506,542
Other comprehensive income (loss), net of tax:
Changes in fair value on available-for-sale securities, net of tax	3,211,042	(4,952,934)	9,642,510	(3,009,581)
Change in fair value of cash flow hedges, net of tax	(339,961)	(31,598)	(1,263,664)	(584,425)
Net gain on sale of investment securities reclassified out of comprehensive income into net income, net of tax	0	(337,890)	0	(341,537)
Total other comprehensive income (loss), net of tax	2,871,081	(5,322,422)	8,378,846	(3,935,543)
Total comprehensive income	$ 33,657,853	$ 17,341,409	$ 67,130,882	$ 40,570,999