Equity Method Investments (Schedule Of Equity Method Investments Reconciliation) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Equity Method Investments [Roll Forward]
Beginning of year	$ 40,350,000us-gaap_EquityMethodInvestments	$ 46,738,000us-gaap_EquityMethodInvestments	$ 44,876,000us-gaap_EquityMethodInvestments
Loss from investments	(5,169,000)	(1,702,000)	1,162,000
Dispositions and other adjustments	1,053,000	(4,686,000)	700,000
End of year	36,234,000us-gaap_EquityMethodInvestments	40,350,000us-gaap_EquityMethodInvestments	46,738,000us-gaap_EquityMethodInvestments
RS Cogen [Member]
Increase (Decrease) in Equity Method Investments [Roll Forward]
Electricity purchased from related party		$ 3,200,000	$ 2,800,000

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ 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 210.5-02.12)

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

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-URI http://asc.fasb.org/extlink&oid=16385135&loc=d3e33749-111570

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- Definition

Amount of the entity's equity method investment which has been sold.

+ References

No definition available.

+ Details

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- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

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-Name Regulation S-X (SX)

-Number 210

-Section 03

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-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

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-Section 45

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-Name Accounting Standards Codification

-Topic 225

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-Name Regulation S-X (SX)

-Number 210

-Section 04

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- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

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