Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (31,234,449)	$ (33,126,019)
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	2,612,271	5,023,421
Provision for Income Taxes	(914,295)	(1,758,197)
Total reclassifications for the period	$ 1,697,976	$ 3,265,224