Organization and Basis of Presentation (Details Textuals) (USD $) In Millions, unless otherwise specified		3 Months Ended
Mar. 31, 2014 customers	Mar. 31, 2013 Proceeds from sale of nuclear decommissioning trust funds [Member]	Mar. 31, 2013 Investment in nuclear decommissioning trust funds [Member]
Number of Electric Customers	2,100,000
Number of Gas Customers	1,200,000
Prior Period Reclassification Adjustment		$ 124	$ (124)
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase Contracts	$ 0

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph b

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5747-111685

Name:	us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant