Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains and losses attributable to changes in net derivative assets and liabilities, included in Operating Income	$ (34,000,000)
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized	(24,000,000)	5,000,000
Settlements	10,000,000	(29,000,000)
Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains and losses attributable to changes in net derivative assets and liabilities, included in Operating Income		34,000,000
Net Derivative Assets (Liabilities) [Member] | PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	31,000,000	(21,000,000)
Included in Income	(34,000,000)	34,000,000
Included in Regulatory Assets/Liabilities	0	35,000,000
Purchases, (Sales)	0	0
Issuances (Settlements)	10,000,000	(29,000,000)
Transfers In (Out)	(2,000,000)	0
Closing Balance	57,000,000	(61,000,000)
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	(9,000,000)	(24,000,000)
Included in Income	(34,000,000)	34,000,000
Included in Regulatory Assets/Liabilities	0	0
Purchases, (Sales)	0	0
Issuances (Settlements)	10,000,000	(29,000,000)
Transfers In (Out)	(2,000,000)	0
Closing Balance	17,000,000	(29,000,000)
Net Derivative Assets (Liabilities) [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	40,000,000	3,000,000
Included in Income	0	0
Included in Regulatory Assets/Liabilities	0	35,000,000
Purchases, (Sales)	0	0
Issuances (Settlements)	0	0
Transfers In (Out)	0	0
Closing Balance	40,000,000	(32,000,000)
Non Recourse Debt [Member] | PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		50,000,000
Included in Income		0
Included in Regulatory Assets/Liabilities		0
Purchases, (Sales)		0
Issuances (Settlements)		0
Transfers In (Out)		0
Closing Balance		$ 50,000,000