Derivatives And Hedging (Schedule Of Fair Value Of Derivative Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Total derivatives in an asset position	$ 113,780	$ 50,793
Total derivatives in a liability position	1,801	4,291
Natural Gas Future Contracts [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Total derivatives in an asset position	105,306	35,783
Natural Gas Future Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total derivatives in a liability position	1,801	4,291
Financial Transmission Rights [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Total derivatives in an asset position	$ 8,474	$ 15,010