Fair Value Measurements And Marketable Securities (Contractual Maturities Of Available For Sale Investments) (Details) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Fair Value Measurements And Marketable Securities
Maturing in one year or less	$ 1,149,000	$ 313,000
Maturing after one year through three years	21,184,000	22,325,000
Maturing after three years	7,544,000	2,202,000
Total debt securities - available for sale	$ 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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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+ Details