Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Settlements		$ (2)		$ (4)		$ (18)		$ 54
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		4		(8)		12		(66)
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized		3		(12)		(6)		(11)
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		8		13		37		88
Included in Income		4	[1]	(8)	[1]	12	[1]	(66)	[2]
Included in Regulatory Assets/Liabilities	[3]	(8)		(9)		(29)		(81)
Purchases, (Sales)		0		0		0		0
Issuances (Settlements)	[4]	(2)		(4)		(18)		54
Transfers In (Out)		0	[5]	0	[5]	0		(3)	[5]
Closing Balance		2		(8)		2		(8)
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		3		(9)		11		(6)
Included in Income		4	[1]	(8)	[1]	12	[1]	(66)	[2]
Included in Regulatory Assets/Liabilities	[3]	0		0		0		0
Purchases, (Sales)		0		0		0		0
Issuances (Settlements)	[4]	(2)		(4)		(18)		54
Transfers In (Out)		0	[5]	0	[5]	0		(3)	[5]
Closing Balance		5		(21)		5		(21)
Net Derivative Assets (Liabilities) [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		5		22		26		94
Included in Income		0	[1]	0	[1]	0	[1]	0	[2]
Included in Regulatory Assets/Liabilities	[3]	(8)		(9)		(29)		(81)
Purchases, (Sales)		0		0		0		0
Issuances (Settlements)	[4]	0		0		0		0
Transfers In (Out)		0	[5]	0	[5]	0		0	[5]
Closing Balance		$ (3)		$ 13		$ (3)		$ 13

[1] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities includes $4 million and $12 million in Operating Income for the three months and nine months ended September 30, 2015, respectively. Of the $4 million in Operating Income, $3 million is unrealized. Of the $12 million in Operating Income, $(6) million is unrealized.

[2] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $(8) million and $(66) million in Operating Income for the three months and nine months ended September 30, 2014, respectively. Of the $(8) million in Operating Income, $(12) million is unrealized. Of the $(66) million in Operating Income, $(11) 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 $(2) million and $(18) million in settlements for the three months and nine months ended September 30, 2015. Includes $(4) million and $54 million in settlements for the three months and nine months ended September 30, 2014.

[5] nine months ended September 30, 2014, $(3) million of net derivative 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 in which the transfers first occurred as per PSEG's policy.