Consolidated Statements of Comprehensive Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 7,108,574	$ 4,813,404	$ 9,894,744	$ 25,246,971
Unrealized gain (loss) on securities:
Unrealized holding gain (loss) during the period, net of income tax expense (benefit)	1,042,317	(1,106,346)	4,115,189	6,999,494
Reclassification adjustment for gains included in net income, net of income tax expense	(364,929)	(661,969)	(2,735,012)	(1,432,946)
Other comprehensive income (loss)	677,388	(1,768,315)	1,380,177	5,566,548
Comprehensive income	$ 7,785,962	$ 3,045,089	$ 11,274,921	$ 30,813,519