Basis of Presentation (Details Textuals) (USD $) In Millions, unless otherwise specified		6 Months Ended
	Jun. 30, 2014 customers	Jun. 30, 2013 Proceeds from sale of nuclear decommissioning trust funds [Member]	Jun. 30, 2013 Investment in nuclear decommissioning trust funds [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Number of Electric Customers	2,100,000
Prior Period Reclassification Adjustment		$ (282)	$ 282
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase Contracts	$ 0