Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (35,891,736)	$ (28,895,257)	$ (67,126,185)	$ (62,021,276)
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	1,915,743	6,542,318	4,528,014	11,565,739
Provision for Income Taxes	(670,509)	(2,289,812)	(1,584,804)	(4,048,009)
Total reclassifications for the period	$ 1,245,234	$ 4,252,506	$ 2,943,210	$ 7,517,730