Summary Of Significant Accounting Policies (Summary Of The Amortized Costs And Fair Values Of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
MARKETABLE SECURITIES, Amortized Cost	$ 22,409	$ 36,392
MARKETABLE SECURITIES, Fair Value	22,404	36,404
MARKETABLE SECURITIES, Gross Unrealized Gains	5	18
MARKETABLE SECURITIES - Gross Unrealized Losses	10	6
Tax-Exempt Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
MARKETABLE SECURITIES, Amortized Cost	8,809	20,813
MARKETABLE SECURITIES, Fair Value	8,804	20,825
MARKETABLE SECURITIES, Gross Unrealized Gains	5	18
MARKETABLE SECURITIES - Gross Unrealized Losses	10	6
Variable Rate Demand Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
MARKETABLE SECURITIES, Amortized Cost	13,600	15,579
MARKETABLE SECURITIES, Fair Value	$ 13,600	$ 15,579

Amount of accumulated pre-tax unrealized gain before deducting pre-tax unrealized loss on investments in available-for-sale debt securities impacting investments.

No definition available.

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Amount of accumulated pre-tax unrealized loss berore deducting pre-tax unrealized gain on investment in available-for-sale debt securities impacting investmetns.

+ References

No definition available.

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- Definition

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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- Definition

Amount of investments in debt securities classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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