Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (28,895,257)	$ (25,031,542)	$ (62,021,276)	$ (45,354,887)
Amounts Reclassified from Other Comprehensive Income [Member] | Unrealized gains(losses) on available-for-sale securities [Member]
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized gain on sale of securities	6,542,318	5,030,124	11,565,739	7,852,331
Provision for Income Taxes	(2,289,812)	(1,760,543)	(4,048,009)	(2,748,316)
Total reclassifications for the period	$ 4,252,506	$ 3,269,581	$ 7,517,730	$ 5,104,015