Commitments And Contingent Liabilities (Environmental Matters) (Detail) (USD $)	1 Months Ended	12 Months Ended						12 Months Ended				12 Months Ended			1 Months Ended							12 Months Ended				12 Months Ended
	Oct. 31, 2012	Dec. 31, 2012 entity mi	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2005 site	Apr. 30, 2009 MW Turbines	Feb. 28, 2009 Defendant	Dec. 31, 2012 PSE&G [Member] MW	Dec. 31, 2011 PSE&G [Member]	Dec. 31, 2010 PSE&G [Member]	May 31, 2012 PSE&G [Member] MW	Dec. 31, 2012 Power [Member]	Dec. 31, 2011 Power [Member]	Dec. 31, 2010 Power [Member]	Dec. 31, 2011 PSEG [Member]	Jun. 30, 2008 Passaic River Site Contingency [Member]	Dec. 31, 2012 Passaic River Site Contingency [Member]	Dec. 31, 2003 Passaic River Site Contingency [Member]	Dec. 31, 2012 Passaic River Site Contingency [Member] Transferred To Power From PSE&G [Member] Plant	Dec. 31, 2012 Passaic River Site Contingency [Member] PSE&G [Member] Plant	Dec. 31, 2012 PSE&G's Former MGP Sites [Member]	Dec. 31, 2012 PSE&G's Former MGP Sites [Member] PSE&G [Member] Person	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] PSE&G [Member]	Dec. 31, 2012 PSD NSR Regulations Site Contingency [Member] Power [Member]	Dec. 31, 2012 MGP Remediation Site Contingency [Member] PSE&G [Member]	Dec. 31, 2012 Remedial Investigation And Feasibility Study [Member]	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] PSE&G [Member]	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] Power [Member]	Dec. 31, 2012 New Jersey Clean Energy Program Unfavorable Regulatory Action [Member] PSE&G [Member]
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss								$ 153,000,000																					$ 195,000,000
Percentage of residential gas supply permitted to be recovered in gas hedging by BPU		80.00%
Number of miles related to the Passaic River constituting a facility as determined by the US Environmental Protection Agency		8
Number of miles on Passaic River tidal reach required to be studied as determined by the US Environmental Protection Agency		17
Number of operating electric generating station (Essex Site)																			1
Number of former generating electric station																				1
Number of former Manufactured Gas Plant (MGP) sites																				4
Original estimated cost of feasibility study																							20,000,000
Estimated, total cost of the study																						110,000,000				30,000,000
Number of sites or facilities impacted water bodies					11
Aggregate number Of defendants In New Jersey Department Of Environmental Protection complaint							320
Period of time for third party defendants to explore possible settlement with State of New Jersey	90 days
Number of potentially responsible parties ("PRPs") in connection with environmental liabilities for operations conducted near Passaic River																						73
Number of current potentially responsible parties ("PRPs") in connection with environmental liabilities for operations conducted near Passaic River																						70
Percentage of cost attributable to potentially responsible party																											5.00%	1.00%
Estimated cleanup costs-low estimate																	1,300,000,000
Estimated cleanup costs-high estimate																	3,700,000,000
Estimated cleanup costs agreed to by two potentially responsible parties																80,000,000
Aggregate number of PRPs directed by the NJDEP to arrange for natural resource damage assessment and interim compensatory restoration along the lower Passaic River																		56
Estimated cost of interim natural resource injury restoration																	950,000,000
Number of legal entities contacted by EPA in conjunction with Newark Bay study area contamination		11
Number of operating electric generating stations located on Hackensack River		2
Number of former MGP contamination sites located on Hackensack river in conjunction with Newark Bay study area contamination		1
Number of MGP sites identified by registrant and the NJDEP requiring some level of remedial action																					38
Estimated expenditures, low end of range																									588,000,000
Estimated expenditures, high end of range																									675,000,000
Accrued environmental costs		537,000,000	643,000,000					486,000,000	592,000,000																588,000,000
Remediation liability recorded as other current liabilities																									113,000,000
Remediation liability recorded as environmental costs in noncurrent liabilities																									475,000,000
Regulatory assets								4,892,000,000	4,897,000,000																588,000,000
Penalty per day from date of violation-minimum																								25,000
Penalty per day from date of violation-maximum																								37,500
Ownership Percentage Of Keystone Coal Fired Plant In Pennsylvania												23.00%
Parent companies share of investment in Clean Air Act requirements															147,000,000
Number of combustion turbines required to be retired to meet NOx emission reduction requirements						86
Number of MW required to be retired to meet NOx emission reduction requirements						1,750
Number of steam electric generation units requiring significant capital investment for additional controls or retirement as determined by NJDEP						4
Number of MW requiring significant capital investment for additional controls or retirement as determined by NJDEP						400
Period of time National Pollutant Discharge Elimination System permit expires from effective date		5 years
New Salem facility cooling towers estimated cost total		1,000,000,000										575,000,000
Total expenditures to date		$ 2,574,000,000	$ 2,083,000,000	$ 2,160,000,000				$ 1,770,000,000	$ 1,302,000,000	$ 1,257,000,000		$ 646,000,000	$ 757,000,000	$ 825,000,000
New Combined Cycle Generating Facilities To Be Built Under Lcapp								2,000			1,300