Fair Value Measurements (PSEG's, Power's And PSE&G's Respective Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	$ 333		$ 262
Total Mark-to-Market Derivative (Liabilities)	(174)		(157)
Cash	1
Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	237		194
Total Mark-to-Market Derivative (Liabilities)	(170)		(148)
Total Estimate Of Fair Value [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	271	[1]	198	[1]
Total Mark-to-Market Derivative (Liabilities)	(172)	[1]	(155)	[1]
Total Estimate Of Fair Value [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	62	[2]	64	[2]
Total Mark-to-Market Derivative (Liabilities)	(2)	[2]	(2)	[2]
Total Estimate Of Fair Value [Member] | Non-Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative (Liabilities)	(50)	[3]	(50)	[3]
Total Estimate Of Fair Value [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	772		685	[4]
Total Estimate Of Fair Value [Member] | Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	323		359	[4]
Total Estimate Of Fair Value [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	305		281	[4]
Total Estimate Of Fair Value [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	48		24	[4]
Total Estimate Of Fair Value [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			172	[4]
Total Estimate Of Fair Value [Member] | Rabbi Trusts - Equity Securities-Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	22
Total Estimate Of Fair Value [Member] | Rabbi Trusts - Debt Securities-Govt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	110
Total Estimate Of Fair Value [Member] | Rabbi Trusts - Debt Securities-Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	41
Total Estimate Of Fair Value [Member] | Rabbi Trusts - Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	53
Total Estimate Of Fair Value [Member] | PSE And G [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets			4	[1]
Total Mark-to-Market Derivative (Liabilities)			(7)	[1]
Total Estimate Of Fair Value [Member] | PSE And G [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			57	[4]
Cash Collateral Netting [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	(88)	[1],[5]	(100)	[1],[5]
Total Mark-to-Market Derivative (Liabilities)	40	[1],[5]	18	[1],[5]
Cash Collateral Netting [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	0	[2],[5]	0	[2],[5]
Total Mark-to-Market Derivative (Liabilities)	0	[2],[5]	0	[2],[5]
Cash Collateral Netting [Member] | Non-Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative (Liabilities)	0	[3],[5]	0	[3],[5]
Cash Collateral Netting [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[4],[5]
Cash Collateral Netting [Member] | Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[4],[5]
Cash Collateral Netting [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[4],[5]
Cash Collateral Netting [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[4],[5]
Cash Collateral Netting [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			0	[4],[5]
Cash Collateral Netting [Member] | Rabbi Trusts - Equity Securities-Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]
Cash Collateral Netting [Member] | Rabbi Trusts - Debt Securities-Govt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]
Cash Collateral Netting [Member] | Rabbi Trusts - Debt Securities-Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]
Cash Collateral Netting [Member] | Rabbi Trusts - Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0	[5]
Cash Collateral Netting [Member] | PSE And G [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets			0	[1],[5]
Total Mark-to-Market Derivative (Liabilities)			0	[1],[5]
Cash Collateral Netting [Member] | PSE And G [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			0	[4],[5]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	0	[1]	0	[1]
Total Mark-to-Market Derivative (Liabilities)	0	[1]	0	[1]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	0	[2]	0	[2]
Total Mark-to-Market Derivative (Liabilities)	0	[2]	0	[2]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Non-Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative (Liabilities)	0	[3]	0	[3]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	772		685	[4]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			19	[4]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Rabbi Trusts - Equity Securities-Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	22
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Rabbi Trusts - Debt Securities-Govt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Rabbi Trusts - Debt Securities-Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Quoted Market Prices Of Identical Assets (Level 1) [Member] | Rabbi Trusts - Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Quoted Market Prices Of Identical Assets (Level 1) [Member] | PSE And G [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets			0	[1]
Total Mark-to-Market Derivative (Liabilities)			0	[1]
Quoted Market Prices Of Identical Assets (Level 1) [Member] | PSE And G [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			6	[4]
Significant Other Observable Inputs (Level 2) [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	280	[1]	257	[1]
Total Mark-to-Market Derivative (Liabilities)	(194)	[1]	(153)	[1]
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	62	[2]	64	[2]
Total Mark-to-Market Derivative (Liabilities)	(2)	[2]	(2)	[2]
Significant Other Observable Inputs (Level 2) [Member] | Non-Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative (Liabilities)	0	[3]	0	[3]
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Significant Other Observable Inputs (Level 2) [Member] | Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	323		359	[4]
Significant Other Observable Inputs (Level 2) [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	305		281	[4]
Significant Other Observable Inputs (Level 2) [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	48		24	[4]
Significant Other Observable Inputs (Level 2) [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			153	[4]
Significant Other Observable Inputs (Level 2) [Member] | Rabbi Trusts - Equity Securities-Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Significant Other Observable Inputs (Level 2) [Member] | Rabbi Trusts - Debt Securities-Govt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	110
Significant Other Observable Inputs (Level 2) [Member] | Rabbi Trusts - Debt Securities-Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	41
Significant Other Observable Inputs (Level 2) [Member] | Rabbi Trusts - Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	53
Significant Other Observable Inputs (Level 2) [Member] | PSE And G [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets			0	[1]
Total Mark-to-Market Derivative (Liabilities)			0	[1]
Significant Other Observable Inputs (Level 2) [Member] | PSE And G [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			51	[4]
Pension And OPEB Plans Level 3 [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	79	[1]	41	[1]
Total Mark-to-Market Derivative (Liabilities)	(18)	[1]	(20)	[1]
Pension And OPEB Plans Level 3 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets	0	[2]	0	[2]
Total Mark-to-Market Derivative (Liabilities)	0	[2]	0	[2]
Pension And OPEB Plans Level 3 [Member] | Non-Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative (Liabilities)	(50)	[3]	(50)	[3]
Pension And OPEB Plans Level 3 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Pension And OPEB Plans Level 3 [Member] | Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Pension And OPEB Plans Level 3 [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Pension And OPEB Plans Level 3 [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0		0	[4]
Pension And OPEB Plans Level 3 [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			0	[4]
Pension And OPEB Plans Level 3 [Member] | Rabbi Trusts - Equity Securities-Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Pension And OPEB Plans Level 3 [Member] | Rabbi Trusts - Debt Securities-Govt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Pension And OPEB Plans Level 3 [Member] | Rabbi Trusts - Debt Securities-Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Pension And OPEB Plans Level 3 [Member] | Rabbi Trusts - Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments	0
Pension And OPEB Plans Level 3 [Member] | PSE And G [Member] | Energy-Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Mark-to-Market Derivative Assets			4	[1]
Total Mark-to-Market Derivative (Liabilities)			(7)	[1]
Pension And OPEB Plans Level 3 [Member] | PSE And G [Member] | Rabbi Trusts - Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measured on Recurring Basis, Investments			$ 0	[4]

[1] Level 2—Fair values for energy-related contracts are obtained primarily using a market-based approach. Most derivative contracts (forward purchase or sale contracts and swaps) are valued using the average of the bid/ask midpoints from multiple broker or dealer quotes or auction prices. Prices used in the valuation process are also corroborated independently by management to determine that values are based on actual transaction data or, in the absence of transactions, bid and offers for the day. Examples may include certain exchange and non-exchange traded capacity and electricity contracts and natural gas physical or swap contracts based on market prices, basis adjustments and other premiums where adjustments and premiums are not considered significant to the overall inputs. Level 3—For energy-related contracts, which include more complex agreements where limited observable inputs or pricing information are available, modeling techniques are employed using assumptions reflective of contractual terms, current market rates, forward price curves, discount rates and risk factors, as applicable. Fair values of other energy contracts may be based on broker quotes that we cannot corroborate with actual market transaction data.

[2] Interest rate swaps are valued using quoted prices on commonly quoted intervals, which are interpolated for periods different than the quoted intervals, as inputs to a market valuation model. Market inputs can generally be verified and model selection does not involve significant management judgment.

[3] For Non-Recourse Debt, see Fair Value Option below.

[4] The fair value measurements table excludes cash of $1 million which is part of the NDT Fund. The NDT Fund maintains investments in various equity and fixed income securities classified as "available for sale." The Rabbi Trust maintains investments in an S&P 500 index fund and various fixed income securities classified as "available for sale." These securities are generally valued with prices that are either exchange provided (equity securities) or market transactions for comparable securities and/or broker quotes (fixed income securities). Level 1—Investments in marketable equity securities within the NDT Fund are primarily investments in common stocks across a broad range of industries and sectors. Most equity securities are priced utilizing the principal market close price or, in some cases, midpoint, bid or ask price (primarily Level 1). The Rabbi Trust equity index fund is valued based on quoted prices in an active market (Level 1). Level 2—NDT and Rabbi Trust fixed income securities are limited to investment grade corporate bonds and United States Treasury obligations or Federal Agency mortgage-backed securities with a wide range of maturities. Since many fixed income securities do not trade on a daily basis, they are priced using an evaluated pricing methodology that varies by asset class and reflects observable market information such as the most recent exchange price or quoted bid for similar securities. Market-based standard inputs typically include benchmark yields, reported trades, broker/dealer quotes, and issuer spreads (primarily Level 2). Short-term investments and certain commingled temporary investments are valued using observable market prices or market parameters such as time-to-maturity, coupon rate, quality rating and current yield (primarily Level 2).

[5] Cash collateral netting represents collateral amounts netted against derivative assets and liabilities as permitted under the accounting guidance for Offsetting of Amounts Related to Certain Contracts.