Organization and Basis of Presentation (Details Textuals) (USD $) In Millions, unless otherwise specified		12 Months Ended
	Dec. 31, 2013 customers	Dec. 31, 2012 Proceeds from sale of nuclear decommissioning trust funds [Member]	Dec. 31, 2011 Proceeds from sale of nuclear decommissioning trust funds [Member]	Dec. 31, 2012 Investment in Nuclear Decommissioning Trust Funds [Member]	Dec. 31, 2011 Investment in Nuclear Decommissioning Trust Funds [Member]
Prior Period Reclassification Adjustment		$ 662	$ 753	$ (662)	$ (753)
Number of Electric Utility Customers	2,100,000
Number of Gas Utility Customers	1,200,000
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase Contracts	$ 0