Commitments And Contingent Liabilities (Environmental Matters) (Details) (USD $)	6 Months Ended									3 Months Ended											12 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2011 gal years mW	Dec. 31, 2010	Apr. 30, 2009 mW	Dec. 15, 2007	Aug. 31, 2006	Jun. 30, 2011 Power [Member] NJ Industrial Site Recovery Act Site Contingency [Member]	Dec. 31, 2010 NJ Industrial Site Recovery Act Site Contingency [Member]	Jun. 30, 2011 Power [Member] PSD NSR Regulations Site Contingency [Member]	Feb. 28, 2009 PSE&G [Member] Power [Member] Passaic River Site Contingency [Member]	Jun. 30, 2008 Passaic River Site Contingency [Member]	Jun. 30, 2011 Passaic River Site Contingency [Member]	Dec. 31, 2007 Passaic River Site Contingency [Member]	Dec. 31, 2003 Passaic River Site Contingency [Member]	Jun. 30, 2011 Passaic River Site Contingency [Member] PSE&G [Member]	Jun. 30, 2011 Passaic River Site Contingency [Member] Transferred To Power From PSE&G [Member]	Jun. 30, 2011 PSE&G [Member] MGP Remediation Site Contingency [Member]	Jun. 30, 2011 MGP Remediation Site Contingency [Member] PSE&G [Member]	Sep. 30, 2010 MGP Remediation Site Contingency [Member] PSE&G [Member]	Dec. 31, 2006 Power [Member] PSE&G's Former MGP Sites [Member]	Jun. 30, 2011 PSE&G's Former MGP Sites [Member]	Dec. 31, 2006 PSE&G's Former MGP Sites [Member] PSE&G [Member]	Jun. 30, 2011 PSE&G's Former MGP Sites [Member] PSE&G [Member]	Jun. 30, 2011 PSE&G [Member]	Dec. 31, 2010 PSE&G [Member]	Dec. 31, 2010 Power [Member]	Jun. 30, 2011 Power [Member]
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
Number of former MGP locations (Harrison Site) which EPA believes that hazardous substances were released																						1
Original estimated cost of feasibility study																					$ 20,000,000
Estimated, total cost of the study																					86,000,000
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																					71
Percentage of cost attributable to potentially responsible party																			1.00%		5.00%
Number of miles of Passaic River which EPA released a draft (Focused Feasibility Study) that proposes six options to address the contamination cleanup												8
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
Expenditures for MGP Remediation																							18,000,000
Estimated expenditures, low end of range																		668,000,000
Estimated expenditures, high end of range																		774,000,000
Accrued environmental costs	646,000,000	669,000,000				50,000,000	50,000,000											668,000,000					594,000,000	617,000,000	51,000,000	51,000,000
Accrued environmental costs, total																							650,000,000
Remediation liability recorded as other current liabilities																	65,000,000
Remediation liability recorded as environmental costs in noncurrent liabilities																	585,000,000
Regulatory assets																650,000,000
Penalty per day from date of violation-minimum								25,000
Penalty per day from date of violation-maximum								37,500
Amount spent on Mercer and Hudson up to date																									1,300,000,000
Ownership percentage of Keystone Coal fired plant in Pennsylvania																										23.00%
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			5
Number of MW requiring significant capital investment for additional controls or retirement as determined by NJDEP			800
Total production capacity	2,000,000
New Salem facility cooling towers estimated cost total	$ 1,000,000,000																									$ 575,000,000