Fair Value Measurements And Marketable Securities (Marketable Debt Securities) (Details) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Amortized Cost, Total	$ 40,169,000	$ 42,947,000
Gross Unrealized Gains, Total	616,000	568,000
Gross Unrealized Losses, Total	(3,000)	(78,000)
Estimated Fair Value, Total	40,782,000	43,437,000
Municipal bonds - available for sale - Estimated Fair Value, Total	29,877,000	24,840,000
Other Than Available For Sale Municipal Bonds [Member]
Amortized Cost, Total	10,589,000	18,029,000
Gross Unrealized Gains, Total	316,000	568,000
Estimated Fair Value, Total	10,905,000	18,597,000
Municipal Bonds- Available-For-Sale [Member]
Amortized Cost, Total	29,580,000	24,918,000
Gross Unrealized Gains, Total	300,000
Gross Unrealized Losses, Total	(3,000)	(78,000)
Municipal bonds - available for sale - Estimated Fair Value, Total	$ 29,877,000	$ 24,840,000

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Number 115
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Number 115
-Paragraph 16
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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+ Details