Financial Instruments And Investments (Contractual Year For Maturity Of Available-For-Sale Securities ) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Contractual Maturity Due For, Mortgaged Backed Securities	10 years
Municipal Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	$ 35,012
2013	772
2014 through 2017	12,237
2018 through 2022	17,259
2023 and Beyond	4,744
Corporate Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	12,111
2013	0
2014 through 2017	4,067
2018 through 2022	4,328
2023 and Beyond	3,716
U.S. Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	25,411
2013	1,281
2014 through 2017	9,660
2018 through 2022	11,202
2023 and Beyond	$ 3,268
Maximum
Schedule of Available-for-sale Securities [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	7 years
Minimum
Schedule of Available-for-sale Securities [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	3 years

Amount of debt securities categorized neither as held-to-maturity nor trading.

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-Name Statement of Financial Accounting Standard (FAS)

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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

-Publisher FASB

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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