Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (105,134,094)	$ (81,038,760)	$ (79,763,583)
Amounts Reclassified from Other Comprehensive Income | Unrealized gains and (losses) on available-for-sale securities
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized gain (loss) on sale of securities	18,129,511	8,368,261	6,653,508
Provision for Income Taxes	(6,345,329)	(2,928,891)	(2,328,728)
Total reclassifications for the period	$ 11,784,182	$ 5,439,370	$ 4,324,780