Financing Receivables (Schedule Of Credit Risk Profile Based On Payment Activity) (Detail) (PSE And G [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]
Credit Risk Profile Based on Payment Activity	$ 201	$ 189
Commercial/Industrial [Member]
Concentration Risk [Line Items]
Credit Risk Profile Based on Payment Activity	185	174
Residential [Member]
Concentration Risk [Line Items]
Credit Risk Profile Based on Payment Activity	$ 16	$ 15

Sum of amounts at risk of not being collected pertaining to a specified reinsurer with respect to disclosure of a concentration of credit risk.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 825

-Section 55

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6487554&loc=d3e32600-158583

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 15A

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 113

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (b)

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