Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ (40,601,708)	$ (42,263,336)	$ (117,317,687)	$ (122,676,422)
Amounts Reclassified from Other Comprehensive Income
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period	(269,971)	(247,763)	(175,306)	(1,283,077)
Amounts Reclassified from Other Comprehensive Income \| Unrealized gains on available-for-sale securities:
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized (loss) gain on sale of securities	(176,777)	145,367	915,414	(342,090)
Provision for Income Taxes	61,872	(50,878)	(320,395)	119,731
Total reclassifications for the period	(114,905)	94,489	595,019	(222,359)
Amounts Reclassified from Other Comprehensive Income \| Unrealized gains (losses) on derivatives
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized (loss) gain on sale of securities	(238,564)	(526,542)	(1,185,116)	(1,631,875)
Provision for Income Taxes	83,498	184,290	414,791	571,157
Total reclassifications for the period	$ (155,066)	$ (342,252)	$ (770,325)	$ (1,060,718)

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (b)(7)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20187-122688

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 55
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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