Commitments And Contingent Liabilities (Environmental Matters) (Detail) (USD $)									1 Months Ended									9 Months Ended				9 Months Ended
	Sep. 30, 2012 entity mi	Dec. 31, 2011	Jul. 31, 2011	Apr. 30, 2009 MW Turbines	Dec. 15, 2007	Sep. 30, 2012 PSE And G [Member]	Dec. 31, 2011 PSE And G [Member]	Sep. 30, 2012 Power [Member]	Dec. 31, 2011 PSEG [Member]	Jun. 30, 2008 Passaic River Site Contingency [Member]	Sep. 30, 2012 Passaic River Site Contingency [Member]	Dec. 31, 2003 Passaic River Site Contingency [Member]	Sep. 30, 2012 Passaic River Site Contingency [Member] Transferred To Power From PSE&G [Member] Plant	Sep. 30, 2012 Passaic River Site Contingency [Member] PSE And G [Member] Plant	Feb. 28, 2009 Passaic River Site Contingency [Member] Power [Member]	Feb. 28, 2009 Passaic River Site Contingency [Member] PSEG [Member] Plant	Sep. 30, 2012 PSE&G's Former MGP Sites [Member]	Sep. 30, 2012 PSE&G's Former MGP Sites [Member] PSE And G [Member] Person	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] PSE And G [Member]	Sep. 30, 2012 PSD NSR Regulations Site Contingency [Member] Power [Member]	Sep. 30, 2012 MGP Remediation Site Contingency [Member] PSE And G [Member]	Sep. 30, 2012 Remedial Investigation And Feasibility Study [Member]	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] PSE And G [Member]	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] Power [Member]
Site Contingency [Line Items]
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		11
Original estimated cost of feasibility study																			$ 20,000,000
Estimated, total cost of the study																		110,000,000				30,000,000
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 defendants including registrant entities Power and PSE&G included in NJDEP complaint filed February 2009															320
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																					610,000,000
Estimated expenditures, high end of range																					697,000,000
Accrued environmental costs	565,000,000	643,000,000				514,000,000	592,000,000														610,000,000
Remediation liability recorded as other current liabilities																					107,000,000
Remediation liability recorded as environmental costs in noncurrent liabilities																					503,000,000
Regulatory assets																					610,000,000
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
Percentage of reduction required by New Jersey regulations on coal fired electric generating units					90.00%
Number of combustion turbines required to be retired to meet NOx emission reduction requirements				102
Number of MW required to be retired to meet NOx emission reduction requirements				2,000
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
Number of states with limits on emissions under CSAPR			28
New Salem facility cooling towers estimated cost total	$ 1,000,000,000							$ 575,000,000