Accumulated Other Comprehensive Income (Loss), Net Of Tax (Schedule Of AOCI) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended			9 Months Ended			3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Power [Member]	Sep. 30, 2012 Power [Member]	Sep. 30, 2013 Power [Member]	Sep. 30, 2012 Power [Member]	Sep. 30, 2012 PSE And G [Member]	Sep. 30, 2013 PSE And G [Member]	Dec. 31, 2012 PSE And G [Member]	Sep. 30, 2012 Other [Member]	Sep. 30, 2012 Energy Related Contracts [Member]	Dec. 31, 2011 Energy Related Contracts [Member]	Sep. 30, 2013 Energy Related Contracts [Member] Power [Member]	Sep. 30, 2013 Energy Related Contracts [Member] Power [Member]	Sep. 30, 2012 Energy Related Contracts [Member] Power [Member]	Sep. 30, 2012 Energy Related Contracts [Member] PSE And G [Member]	Sep. 30, 2012 Energy Related Contracts [Member] Other [Member]	Sep. 30, 2012 Pension and OPEB Plans [Member]	Dec. 31, 2011 Pension and OPEB Plans [Member]	Sep. 30, 2013 Pension and OPEB Plans [Member] Power [Member]	Sep. 30, 2013 Pension and OPEB Plans [Member] Power [Member]	Sep. 30, 2012 Pension and OPEB Plans [Member] Power [Member]	Sep. 30, 2012 Pension and OPEB Plans [Member] PSE And G [Member]	Sep. 30, 2012 Pension and OPEB Plans [Member] Other [Member]	Sep. 30, 2012 Available-for-Sale Securities [Member]	Dec. 31, 2011 Available-for-Sale Securities [Member]	Sep. 30, 2013 Available-for-Sale Securities [Member] Power [Member]	Sep. 30, 2013 Available-for-Sale Securities [Member] Power [Member]	Sep. 30, 2012 Available-for-Sale Securities [Member] Power [Member]	Sep. 30, 2012 Available-for-Sale Securities [Member] PSE And G [Member]	Sep. 30, 2012 Available-for-Sale Securities [Member] Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning Balance			$ (388)	$ (337)	$ (303)		$ (328)			$ 1	$ 2		$ 11	$ 31	$ 4	$ 9				$ (415)	$ (438)	$ (405)	$ (422)				$ 82	$ 70	$ 98	$ 85
Other Comprehensive Income (Loss), Net of Tax	24	(12)	50	15	24	(15)	49	11	0			4			(1)	(6)	(21)	0	1			8	25	21	0	2			17	30	11	0	1
Accumulated Other Comprehensive Income (Loss), Ending Balance	$ (338)	$ (322)	$ (338)	$ (322)	$ (279)		$ (279)			$ 1	$ 2		$ 11	$ 31	$ 3	$ 3				$ (415)	$ (438)	$ (397)	$ (397)				$ 82	$ 70	$ 115	$ 115

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e681-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669686-108580

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-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 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 14, 17, 26

-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 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

+ Details