Equity Method Investments (Schedule Of Equity Method Investments Reconciliation) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Equity Method Investments [Line Items]
Beginning of year	$ 44,876,000	$ 40,697,000	$ 39,580,000
Loss from investments	1,162,000	(88,000)	(2,469,000)
Dispositions and other adjustments	700,000	4,267,000	3,586,000
End of year	46,738,000	44,876,000	40,697,000
RS Cogen [Member]
Schedule of Equity Method Investments [Line Items]
Electricity purchased from related party	$ 2,800,000	$ 41,100,000	$ 50,800,000