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	Jun. 30, 2011		Dec. 31, 2010
Total Mark-to-Market Derivative Assets	$ 198		$ 261
Other Debt Securities [Member] | Total Estimate Of Fair Value [Member]
Fair Value, Measured on Recurring Basis, Investments	283		255
US States And Political Subdivisions Debt Securities [Member] | Total Estimate Of Fair Value [Member]
Fair Value, Measured on Recurring Basis, Investments	339		303
Equity Securities [Member] | Total Estimate Of Fair Value [Member]
Fair Value, Measured on Recurring Basis, Investments	689		735
Other Securities [Member] | Total Estimate Of Fair Value [Member]
Fair Value, Measured on Recurring Basis, Investments	130		70
Total Estimate Of Fair Value [Member] | Energy-Related Contracts [Member]
Total Mark-to-Market Derivative Assets	151	[1]	222	[1]
Fair Value, Liabilities Measured on Recurring Basis, Derivative Financial Instruments, Liabilities	88	[1]	(125)	[1]
Total Estimate Of Fair Value [Member] | Interest Rate Swap [Member]
Total Mark-to-Market Derivative Assets	47	[2]	39	[2]
Total Estimate Of Fair Value [Member] | Rabbi Trusts Mutual Funds [Member]
Fair Value, Measured on Recurring Basis, Investments	168	[3]	160	[3]
Total Estimate Of Fair Value [Member] | Other Derivative Long Term Investments [Member]
Fair Value, Measured on Recurring Basis, Investments	4	[4]	2	[4]
Other Debt Securities [Member] | Cash Collateral Netting [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[5]
US States And Political Subdivisions Debt Securities [Member] | Cash Collateral Netting [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[5]
Equity Securities [Member] | Cash Collateral Netting [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[5]
Other Securities [Member] | Cash Collateral Netting [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[5]	0	[5]
Cash Collateral Netting [Member] | Energy-Related Contracts [Member]
Total Mark-to-Market Derivative Assets	(2)	[1],[5]	(135)	[1],[5]
Fair Value, Liabilities Measured on Recurring Basis, Derivative Financial Instruments, Liabilities	0	[1],[5]	74	[1],[5]
Cash Collateral Netting [Member] | Interest Rate Swap [Member]
Total Mark-to-Market Derivative Assets	0	[2],[5]	0	[2],[5]
Cash Collateral Netting [Member] | Rabbi Trusts Mutual Funds [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[3],[5]	0	[3],[5]
Cash Collateral Netting [Member] | Other Derivative Long Term Investments [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[4],[5]	0	[4],[5]
Other Debt Securities [Member] | Quoted Market Prices For Identical Assets (Level 1) [Member]
Fair Value, Measured on Recurring Basis, Investments	0		0
US States And Political Subdivisions Debt Securities [Member] | Quoted Market Prices For Identical Assets (Level 1) [Member]
Fair Value, Measured on Recurring Basis, Investments	0		0
Equity Securities [Member] | Quoted Market Prices For Identical Assets (Level 1) [Member]
Fair Value, Measured on Recurring Basis, Investments	689		735
Other Securities [Member] | Quoted Market Prices For Identical Assets (Level 1) [Member]
Fair Value, Measured on Recurring Basis, Investments	1		0
Quoted Market Prices For Identical Assets (Level 1) [Member] | Energy-Related Contracts [Member]
Total Mark-to-Market Derivative Assets	0	[1]	0	[1]
Fair Value, Liabilities Measured on Recurring Basis, Derivative Financial Instruments, Liabilities	0	[1]	0	[1]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Interest Rate Swap [Member]
Total Mark-to-Market Derivative Assets	0	[2]	0	[2]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Rabbi Trusts Mutual Funds [Member]
Fair Value, Measured on Recurring Basis, Investments	20	[3]	18	[3]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Other Derivative Long Term Investments [Member]
Fair Value, Measured on Recurring Basis, Investments	4	[4]	2	[4]
Other Debt Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Measured on Recurring Basis, Investments	283		255
US States And Political Subdivisions Debt Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Measured on Recurring Basis, Investments	339		303
Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Measured on Recurring Basis, Investments	0		0
Other Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Measured on Recurring Basis, Investments	129		62
Significant Other Observable Inputs (Level 2) [Member] | Energy-Related Contracts [Member]
Total Mark-to-Market Derivative Assets	139	[1]	228	[1]
Fair Value, Liabilities Measured on Recurring Basis, Derivative Financial Instruments, Liabilities	71	[1]	(117)	[1]
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap [Member]
Total Mark-to-Market Derivative Assets	47	[2]	39	[2]
Significant Other Observable Inputs (Level 2) [Member] | Rabbi Trusts Mutual Funds [Member]
Fair Value, Measured on Recurring Basis, Investments	148	[3]	142	[3]
Significant Other Observable Inputs (Level 2) [Member] | Other Derivative Long Term Investments [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[4]	0	[4]
Other Debt Securities [Member] | Pension And OPEB Plans' Level 3 [Member]
Fair Value, Measured on Recurring Basis, Investments	0		0
US States And Political Subdivisions Debt Securities [Member] | Pension And OPEB Plans' Level 3 [Member]
Fair Value, Measured on Recurring Basis, Investments	0		0
Equity Securities [Member] | Pension And OPEB Plans' Level 3 [Member]
Fair Value, Measured on Recurring Basis, Investments	0		0
Other Securities [Member] | Pension And OPEB Plans' Level 3 [Member]
Fair Value, Measured on Recurring Basis, Investments	0		8
Pension And OPEB Plans' Level 3 [Member] | Energy-Related Contracts [Member]
Total Mark-to-Market Derivative Assets	14	[1]	129	[1]
Fair Value, Liabilities Measured on Recurring Basis, Derivative Financial Instruments, Liabilities	17	[1]	(82)	[1]
Pension And OPEB Plans' Level 3 [Member] | Interest Rate Swap [Member]
Total Mark-to-Market Derivative Assets	0	[2]	0	[2]
Pension And OPEB Plans' Level 3 [Member] | Rabbi Trusts Mutual Funds [Member]
Fair Value, Measured on Recurring Basis, Investments	0	[3]	0	[3]
Pension And OPEB Plans' Level 3 [Member] | Other Derivative Long Term Investments [Member]
Fair Value, Measured on Recurring Basis, Investments	$ 0	[4]	$ 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 is available, modeling techniques are employed using assumptions reflective of contractual terms, current market rates, forward price curves, discount rates and risk factors, as applicable. For certain energy-related option contracts where daily settled option prices are not observable, a traditional Black-Scholes valuation methodology is used which incorporates an internally developed volatility curve that is considered a significant unobservable input. Fair values of other energy contracts may be based on broker quotes that we cannot corroborate with actual market transaction data. We considered the creditworthiness of our counterparties in the valuation of our energy-related contracts and the impacts are immaterial.

[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] Power's NDT funds maintain investments in various equity and fixed income securities classified as "available for sale." These securities are valued using quoted market prices, broker or dealer quotations or alternative pricing sources with reasonable levels of price transparency. All fair value measurements for the fund securities are provided by the trustees of these funds. Investments in marketable equity securities within the NDT funds 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). Power's NDT investments in fixed income securities are primarily with investment grade corporate bonds and United States Treasury obligations or Federal Agency mortgage-backed securities with a wide range of maturities. Fixed income securities are priced using an evaluated pricing methodology that reflects observable market information such as the most recent exchange price or quoted bid for similar securities (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). The Rabbi Trust mutual funds are mainly invested in a United States bond index fund, an S&P 500 index fund and a commingled temporary investment fund. The equity index fund is valued based on quoted prices in an active market (Level 1) while the bond index fund is valued using recent exchange prices or a quoted bid (Level 2).

[4] Other long-term investments consist of equity securities and are valued using a market based approach based on quoted market prices.

[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.