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	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
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	$ 42
Gains and losses attributable to changes in net derivative assets and liabilities, included in OCI	0	2
Gains and losses attributable to changes in net derivative assets and liabilities, included in Income from Discontinued Operations		3
Gains and losses attributable to changes in net derivative assets and liabilities, unrealized	(15)	9
Purchases	66
Sales		36
Issuances		25
Settlements	(57)	(12)
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Issuances		50
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		17
Net Derivative Assets (Liabilities) [Member] | PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	21	47
Included in Income	42	22	[1]
Included in Regulatory Assets/Liabilities	(37)	(8)	[2]
Purchases, (Sales)	0	30	[3]
Issuances (Settlements)	(57)	(37)	[4]
Transfers In (Out)	0	(33)	[5]
Closing Balance	(31)	21
Net Derivative Assets (Liabilities) [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	24	42
Included in Income	42	22	[1]
Included in Regulatory Assets/Liabilities	0	0	[2]
Purchases, (Sales)	0	30	[3]
Issuances (Settlements)	(57)	(37)	[4]
Transfers In (Out)	0	(33)	[5]
Closing Balance	9	24
Net Derivative Assets (Liabilities) [Member] | PSE&G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	(3)	5
Included in Income	0	0	[1]
Included in Regulatory Assets/Liabilities	(37)	(8)	[2]
Purchases, (Sales)	0	0	[3]
Issuances (Settlements)	0	0	[4]
Transfers In (Out)	0	0	[5]
Closing Balance	(40)	(3)
NDT Funds [Member] | PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		8
Transfers In (Out)		(8)	[5]
NDT Funds [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance		8
Included in Income		0	[1]
Included in Regulatory Assets/Liabilities		0	[2]
Purchases, (Sales)		0	[3]
Issuances (Settlements)		0	[4]
Transfers In (Out)		(8)	[5]
Non Recourse Debt [Member] | PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Opening Balance	(50)	0
Included in Income	50	0	[1]
Included in Regulatory Assets/Liabilities	0	0	[2]
Purchases, (Sales)	0	0	[3]
Issuances (Settlements)	0	(50)	[4]
Transfers In (Out)	0	0	[5]
Closing Balance	$ 0	$ (50)

[1] PSEG’s and Power’s gains and losses attributable to changes in net derivative assets and liabilities include $42 million and $17 million in Operating Income in 2012 and 2011, $0 million and $2 million in OCI in 2012 and 2011, and $3 million in Income from Discontinued Operations in 2011. Of the $42 million in Operating Income in 2012, $(15) million is unrealized. Of the $17 million in Operating Income in 2011, $9 million is unrealized. Energy Holding's release from its obligations under the non-recourse debt is included in PSEG's Operating Income and is offset by the write-off of the related assets.

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

[3] Includes $66 million in purchases and $(36) million in sales in 2011.

[4] $(57) million in settlements for derivative contracts in 2012. Includes $(25) million in issuances and $(12) million in settlements for derivative contracts and includes $(50) million of issuances due to initial recognition of lessor notes resulting from rejection of the Dynegy leveraged leases in 2011. See Fair Value Option discussion.

[5] During the year ended December 31, 2012, there were no transfers among levels. During the year ended December 31, 2011, $8 million of assets in the NDT Fund were transferred from Level 3 to Level 2, due to more observable pricing for the underlying securities and $33 million of net derivative assets were transferred from Level 3 to Level 2 due to more available observable market data. The transfers were recognized as of the beginning of the first quarter and fourth quarter, respectively, (i.e. the quarters in which the transfers occurred), as per PSEG’s policy.