CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) [Abstract]
Net income	$ 27,965,264	$ 21,842,711
Other comprehensive income (loss), net of tax:
Changes in fair value on available-for-sale securities, net of tax	6,431,468	1,936,058
Change in fair value of cash flow hedges, net of tax	(923,703)	(552,828)
Net gain on sale of investment securities reclassified out of comprehensive income into net income, net of tax	0	3,648
Total other comprehensive income (loss), net of tax	5,507,765	1,386,878
Total comprehensive income	$ 33,473,029	$ 23,229,589