Commitments And Contingent Liabilities (Environmental Matters) (Detail)	1 Months Ended	12 Months Ended
	Jun. 30, 2008 USD ($)	Dec. 31, 2015 USD ($) Potentially_Responsible_Party site entity Station Plant mi	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2015 USD ($)	Mar. 31, 2007 Potentially_Responsible_Party	Dec. 31, 2006	Dec. 31, 2003 Potentially_Responsible_Party
Site Contingency [Line Items]
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 | mi		17
Number Of Miles Pertaining To Passaic River Tidal Reach Required To Be Studied By Epa | mi		8
Number of legal entities contacted by EPA in conjunction with Newark Bay study area contamination | entity		11
Number of operating electric generating stations located on Hackensack River | Station		2
Number of former MGP contamination sites located on Hackensack river in conjunction with Newark Bay study area contamination | site		1
Accrued environmental costs		$ 415,000,000	$ 417,000,000
New Salem facility cooling towers estimated cost total		1,000,000,000
Operation and Maintenance		2,978,000,000	3,150,000,000	$ 2,887,000,000
New England Generation Fleet		11,842,000,000	11,153,000,000
Clean Energy Program Current		142,000,000	142,000,000
PSE&G [Member]
Site Contingency [Line Items]
Percentage Of Cost Attributable To Potentially Responsible Party							7.00%
Accrued environmental costs		365,000,000	364,000,000
Regulatory assets		3,360,000,000	3,764,000,000
Operation and Maintenance		1,560,000,000	1,558,000,000	1,639,000,000
New England Generation Fleet		569,000,000	521,000,000
Clean Energy Program Current		$ 142,000,000	142,000,000
Power [Member]
Site Contingency [Line Items]
Ownership Percentage Of Keystone Coal Fired Plant In Pennsylvania		23.00%
New Salem facility cooling towers estimated cost total		$ 575,000,000
Operation and Maintenance		1,057,000,000	1,186,000,000	$ 1,224,000,000
New England Generation Fleet		11,273,000,000	$ 10,632,000,000
New Jersey Clean Energy Program Unfavorable Regulatory Action [Member]
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss		345,000,000
New Jersey Clean Energy Program Unfavorable Regulatory Action [Member] | PSE&G [Member]
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss		200,000,000
Clean Energy Program Current		142,000,000
PSD NSR Regulations Site Contingency [Member] | Power [Member]
Site Contingency [Line Items]
Penalty per day from date of violation-minimum		25,000
Penalty per day from date of violation-maximum		37,500
MGP Remediation Site Contingency [Member] | PSE&G [Member]
Site Contingency [Line Items]
Estimated expenditures, low end of range		431,000,000
Estimated expenditures, high end of range		499,000,000
Accrued environmental costs		431,000,000
Remediation liability recorded as other current liabilities		76,000,000
Remediation liability recorded as environmental costs in noncurrent liabilities		355,000,000
Regulatory assets		431,000,000
Remedial Investigation And Feasibility Study [Member]
Site Contingency [Line Items]
Estimated, total cost of the study		30,000,000
Estimated Total Cost Of Study Low End of Range		$ 25,000,000
Passaic River mile 10.9 contaminant removal [Member]
Site Contingency [Line Items]
Percentage Of Cost Attributable To Potentially Responsible Party		3.00%
PSE&G's Former MGP Sites [Member]
Site Contingency [Line Items]
Estimated, total cost of the study		$ 163,000,000
Number Of Potentially Responsible Parties In Connection With Environmental Liabilities For Operations Conducted Near Passaic River | Potentially_Responsible_Party		54				73
Number of MGP sites identified by registrant and the NJDEP requiring some level of remedial action | site		38
Total Spend of Study to date		$ 147,000,000
Company Share of Total Spend of Study to date		10,000,000
PSE&G's Former MGP Sites [Member] | Power [Member]
Site Contingency [Line Items]
Percentage Of Cost Attributable To Potentially Responsible Party							1.00%
Passaic River Site Contingency [Member]
Site Contingency [Line Items]
Estimated cleanup costs-low estimate		365,000,000
Estimated cleanup costs-high estimate		3,250,000,000
Estimated Cleanup Costs EPA Preferred Method		1,700,000,000
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 | Potentially_Responsible_Party								56
Estimated cost of interim natural resource injury restoration		950,000,000
CPG Estimated Cleanup Costs Low Estimate		518,000,000
CPG Estimated Cleanup Costs High Estimate		3,200,000,000
CPG Targeted Method Cleanup Costs Low Estimate		518,000,000
CPG Targeted Remedy Cleanup Costs High Estimate		$ 772,000,000
Passaic River Site Contingency [Member] | Transferred To Power From PSE&G [Member]
Site Contingency [Line Items]
Number of operating electric generating station (Essex Site) | Plant		1
Passaic River Site Contingency [Member] | PSE&G [Member]
Site Contingency [Line Items]
Number of former generating electric station | Plant		1
Number of former Manufactured Gas Plant (MGP) sites | Plant		4
CPG Targeted Method Cleanup Costs Low Estimate		$ 10,000,000
Passaic River Site Contingency [Member] | Power [Member]
Site Contingency [Line Items]
CPG Targeted Method Cleanup Costs Low Estimate		$ 3,000,000
New England Fleet [Member] | Power [Member]
Site Contingency [Line Items]
New England Generation Fleet					$ 210,000,000