Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Settlements	$ (12)		$ 59
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	3		(64)
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized	(9)		(5)
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	37		88
Included in Income	3	[1]	(64)	[2]
Included in Regulatory Assets/Liabilities	(19)	[3]	(82)	[3]
Purchases, (Sales)	0		0
Issuances (Settlements)	(12)	[4]	59	[4]
Transfers In (Out)	0		0
Closing Balance	9		1
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	11		(6)
Included in Income	3	[1]	(64)	[2]
Included in Regulatory Assets/Liabilities	0	[3]	0	[3]
Purchases, (Sales)	0		0
Issuances (Settlements)	(12)	[4]	59	[4]
Transfers In (Out)	0		0
Closing Balance	2		(11)
Net Derivative Assets (Liabilities) [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	26		94
Included in Income	0	[1]	0	[2]
Included in Regulatory Assets/Liabilities	(19)	[3]	(82)	[3]
Purchases, (Sales)	0		0
Issuances (Settlements)	0	[4]	0	[4]
Transfers In (Out)	0		0
Closing Balance	$ 7		$ 12

[1] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $3 million in Operating Income for the three months ended March 31, 2015, respectively. Of the $3 million in Operating Income, $(9) million is unrealized.

[2] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $(64) million in Operating Income for the three months ended March 31, 2014. Of the $(64) million in Operating Income, $(5) million is unrealized.

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

[4] Represents $(12) million and $59 million in settlements for the three months ended March 31, 2015 and 2014.