Financial Risk Management Activities (Schedule Of Derivative Instruments Fair Value In Balance Sheets) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	$ 142	[1]	$ 138	[1]
Derivative Contracts, Noncurrent Assets	161	[1]	153	[1]
Total Mark-to-Market Derivative Assets	303	[1]	291	[1]
Derivative Contracts, Current Liabilities	(42)	[1]	(46)	[1]
Derivative Contracts, Noncurrent Liabilities	(158)	[1]	(122)	[1]
Total Mark-to-Market Derivative (Liabilities)	(200)	[1]	(168)	[1]
Net Mark-to-Market Derivative Assets (Liabilities)	103	[1]	123	[1]
Net cash collateral received in connection with net derivative contracts	1		2
Power [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	106	[1]	118	[1]
Derivative Contracts, Noncurrent Assets	58	[1]	49	[1]
Total Mark-to-Market Derivative Assets	164	[1]	167	[1]
Derivative Contracts, Current Liabilities	(42)	[1]	(46)	[1]
Derivative Contracts, Noncurrent Liabilities	(20)	[1]	(15)	[1]
Total Mark-to-Market Derivative (Liabilities)	(62)	[1]	(61)	[1]
Net Mark-to-Market Derivative Assets (Liabilities)	102	[1]	106	[1]
Power [Member] | Netting [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	(201)	[2]	(217)	[2]
Derivative Contracts, Noncurrent Assets	(41)	[2]	(26)	[2]
Total Mark-to-Market Derivative Assets	(242)	[2]	(243)	[2]
Derivative Contracts, Current Liabilities	201	[2]	219	[2]
Derivative Contracts, Noncurrent Liabilities	42	[2]	26	[2]
Total Mark-to-Market Derivative (Liabilities)	243	[2]	245	[2]
Net Mark-to-Market Derivative Assets (Liabilities)	1	[2]	2	[2]
Power [Member] | Energy-Related Contracts [Member] | Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	1		3
Derivative Contracts, Noncurrent Assets	0		0
Total Mark-to-Market Derivative Assets	1		3
Derivative Contracts, Current Liabilities	0		0
Derivative Contracts, Noncurrent Liabilities	0		0
Total Mark-to-Market Derivative (Liabilities)	0		0
Net Mark-to-Market Derivative Assets (Liabilities)	1		3
PSE And G [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	21		5
Derivative Contracts, Noncurrent Assets	76		62
Derivative Contracts, Noncurrent Liabilities	(138)		(107)
PSEG [Member] | Interest Rate Swap [Member] | Fair Value Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	15	[1]	15	[1]
Derivative Contracts, Noncurrent Assets	27	[1]	42	[1]
Total Mark-to-Market Derivative Assets	42	[1]	57	[1]
Derivative Contracts, Current Liabilities	0	[1]	0	[1]
Derivative Contracts, Noncurrent Liabilities	0	[1]	0	[1]
Total Mark-to-Market Derivative (Liabilities)	0	[1]	0	[1]
Net Mark-to-Market Derivative Assets (Liabilities)	42	[1]	57	[1]
Not Designated as Hedging Instrument [Member] | Power [Member] | Energy-Related Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	306		332
Derivative Contracts, Noncurrent Assets	99		75
Total Mark-to-Market Derivative Assets	405		407
Derivative Contracts, Current Liabilities	(243)		(265)
Derivative Contracts, Noncurrent Liabilities	(62)		(41)
Total Mark-to-Market Derivative (Liabilities)	(305)		(306)
Net Mark-to-Market Derivative Assets (Liabilities)	100		101
Not Designated as Hedging Instrument [Member] | PSE And G [Member] | Energy-Related Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	21	[1]	5	[1]
Derivative Contracts, Noncurrent Assets	76	[1]	62	[1]
Total Mark-to-Market Derivative Assets	97	[1]	67	[1]
Derivative Contracts, Current Liabilities	0	[1]	0	[1]
Derivative Contracts, Noncurrent Liabilities	(138)	[1]	(107)	[1]
Total Mark-to-Market Derivative (Liabilities)	(138)	[1]	(107)	[1]
Net Mark-to-Market Derivative Assets (Liabilities)	(41)	[1]	(40)	[1]
Current Assets [Member]
Derivatives, Fair Value [Line Items]
Net cash collateral received in connection with net derivative contracts	1		(3)
Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Net cash collateral received in connection with net derivative contracts			$ 5

[1] Substantially all of Power's and PSEG's derivative instruments are contracts subject to master netting agreements. Contracts not subject to master netting or similar agreements are immaterial and did not have any collateral posted or received as of June 30, 2013 and December 31, 2012. PSE&G does not have any derivative contracts subject to master netting or similar agreements.

[2] Represents the netting of fair value balances with the same counterparty (where the right of offset exists) and the application of collateral. All cash collateral received or posted that has been allocated to derivative positions, where the right of offset exists, has been offset in the statement of financial position. As of June 30, 2013 and December 31, 2012, net cash collateral paid of $1 million and $2 million, respectively, were netted against the corresponding net derivative contract positions. Of the $1 million as of June 30, 2013, cash collateral of $1 million was netted against current liabilities. Of the $2 million as of December 31, 2012, cash collateral of $(3) million and $5 million were netted against current assets and current liabilities, respectively.