Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (31,655,724)	$ (25,522,293)	$ (93,677,000)	$ (70,877,180)
Amounts Reclassified from Other Comprehensive Income | Unrealized gains on available-for-sale securities:
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized gain on sale of securities	2,317,289	6,463,447	13,883,028	14,315,778
Provision for Income Taxes	(811,051)	(2,262,206)	(4,859,060)	(5,010,522)
Total reclassifications for the period	$ 1,506,238	$ 4,201,241	$ 9,023,968	$ 9,305,256