Organization, Basis Of Presentation And Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2011
General Plant Assets [Member]
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years to 25 years
Fossil Production Assets [Member]
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	10 years to 79 years
Nuclear Production Assets [Member]
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	approximately 60 years
Pumped Storage Facilities [Member]
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	76 years