Derivatives And Risk Management (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Payments for (Proceeds from) Derivative Instrument, Financing Activities	$ (2,901,000)	$ 18,547,000	$ 10,557,000
Secured Debt	1,376,700,000	1,336,700,000
Cash deposited as collateral	26,100,000	10,100,000
Derivative, Fair Value, Amount Offset Against Collateral, Net	8,732,000	9,707,000
Liability position at aggregate fair value	13,300,000	35,900,000
Collateral agreements	12,600,000	25,800,000
Energy Derivative Contracts [Member]
Derivative [Line Items]
Letters of credit outstanding	20,300,000	28,100,000
First Mortgage [Member] | 2041 [Member]
Derivative [Line Items]
Secured Debt	$ 85,000,000	$ 85,000,000