Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Settlements	$ 51,000,000		$ 8,000,000
Net Assets Measured At Fair Value On A Recurring Basis	2,500,000,000		2,500,000,000
Net Assets Measured At Fair Value On A Recurring Basis Measured Using Unobservable Input And Classified As Level3	37,000,000		88,000,000
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	(31,000,000)		(27,000,000)
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized	22,000,000		(19,000,000)
Derivative [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net	(3,000,000)		4,000,000
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	88,000,000		(31,000,000)
Included in Income	31,000,000	[1]	27,000,000	[1]
Included in Regulatory Assets/Liabilities	(68,000,000)	[2]	134,000,000	[2]
Purchases, (Sales)	0		0
Issuances (Settlements)	(51,000,000)	[3]	(8,000,000)	[3]
Transfers In (Out)	3,000,000	[4]	(4,000,000)	[4]
Closing Balance	37,000,000		88,000,000
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	(6,000,000)		9,000,000
Included in Income	31,000,000	[1]	27,000,000	[1]
Included in Regulatory Assets/Liabilities	0	[2]	0	[2]
Purchases, (Sales)	0		0
Issuances (Settlements)	(51,000,000)	[3]	(8,000,000)	[3]
Transfers In (Out)	3,000,000	[4]	(4,000,000)	[4]
Closing Balance	11,000,000		(6,000,000)
Net Derivative Assets (Liabilities) [Member] | PSE&G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	94,000,000		(40,000,000)
Included in Income	0	[1]	0	[1]
Included in Regulatory Assets/Liabilities	(68,000,000)	[2]	134,000,000	[2]
Purchases, (Sales)	0		0
Issuances (Settlements)	0	[3]	0	[3]
Transfers In (Out)	0	[4]	0	[4]
Closing Balance	$ 26,000,000		$ 94,000,000

[1] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $(31) million and $(27) million in Operating Income in 2014 and 2013, respectively. Of the $(31) million in Operating Income in 2014, $22 million is unrealized. Of the $(27) million in Operating Income in 2013, $(19) million is unrealized.

[2] Mainly includes gains/losses on PSE&G’s derivative contracts that are not included in either earnings or Accumulated Other Comprehensive Income (Loss), as they are deferred as a Regulatory Asset/Liability and are expected to be recovered from/returned to PSE&G’s customers.

[3] Represents $51 million and $8 million in settlements for derivative contracts in 2014 and 2013, respectively.

[4] During the years ended December 31, 2014 and 2013, $(3) million and $4 million, respectively, of net derivatives assets/liabilities were transferred from Level 3 to Level 2 due to more observable pricing for the underlying securities. The transfers were recognized as of the beginning of the quarters (i.e. the quarter in which the transfers occurred), as per PSEG’s policy.