Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (37,308,163)	$ (39,289,618)
Amounts Reclassified from Other Comprehensive Income
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period	(105,248)	(659,733)
Amounts Reclassified from Other Comprehensive Income | Unrealized gains on available-for-sale securities:
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized gain (loss) on sale of securities	253,413	(462,724)
Provision for Income Taxes	(88,695)	161,953
Total reclassifications for the period	164,718	(300,771)
Amounts Reclassified from Other Comprehensive Income | Unrealized gains (losses) on derivatives
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized gain (loss) on sale of securities	(415,333)	(552,250)
Provision for Income Taxes	145,367	193,288
Total reclassifications for the period	$ (269,966)	$ (358,962)