Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 8,748,711	$ 7,653,734	$ 10,052,967	$ 16,758,157
Unrealized gain (loss) on securities:
Unrealized holding income (loss) during the period, net of income tax expense (benefit)	(447,448)	(1,175,052)	8,050,945	(25,511,627)
Reclassification adjustment for gains included in net income, net of income tax expense	(231,838)	(230,449)	(1,515,960)	(1,942,849)
Other comprehensive income (loss)	(679,286)	(1,405,501)	6,534,985	(27,454,476)
Comprehensive income (loss)	$ 8,069,425	$ 6,248,233	$ 16,587,952	$ (10,696,319)