Investments In Securities (Schedule Of Gross Realized Gains And Losses On Securities) (Details) - USD ($)	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized gains	$ 303,116	$ 9,199
Total, Gross realized losses	(159,831)	(396)
Net realized gain from securities	143,285	8,803
Gain on other investments	6,545	6,000
Total	6,545	6,000
Net realized gain on investments	149,830	14,803
General Obligations Of U.S. States, Territories And Political Subdivisions
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized losses	0	(396)
Issuer Obligations Of U S States Territories And Political Subdivisions Special Revenue [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized gains	160	0
Total, Gross realized losses	(85)	0
Corporate Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized gains	0	999
Common Stocks And Nonredeemable Preferred Stocks
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized gains	227,960	8,200
Total, Gross realized losses	(116,952)	0
Impairments of Debt And Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized losses	(42,794)	0
Auction Rate Securities
Schedule of Available-for-sale Securities [Line Items]
Total, Gross realized gains	$ 74,996	$ 0

Gain on other investments.

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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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 and losses recognized for other than temporary impairments (OTTI) of the subject investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (c)-(e)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27405-111563

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The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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