Fair Value Measurements (Fair Value Of Debt) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	$ 8,250		$ 7,939
Long-Term Debt, Fair Value	8,726		9,324
Power - Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	2,041	[1]	2,340	[1]
Long-Term Debt, Fair Value	2,361	[1]	2,818	[1]
PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	5,540	[1]	4,795	[1]
Long-Term Debt, Fair Value	5,627	[1]	5,606	[1]
Transition Funding (PSE&G) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	590	[1]	690	[1]
Long-Term Debt, Fair Value	643	[1]	765	[1]
Transition Funding II (PSE&G) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	27	[1]	32	[1]
Long-Term Debt, Fair Value	28	[1]	34	[1]
Energy Holdings Project Level, Non-Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	25	[2]	44	[2]
Long-Term Debt, Fair Value	25	[2]	44	[2]
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	27	[3]	38	[3]
Long-Term Debt, Fair Value	$ 42	[3]	$ 57	[3]

[1] The debt fair valuation is based on the present value of each bond’s future cash flows. The discount rates used in the present value analysis are based on an estimate of new issue bond yields across the treasury curve. When a bond has embedded options, an interest rate model is used to reflect the impact of interest rate volatility into the analysis (primarily Level 2 measurements).

[2] Non-recourse project debt is valued as equivalent to the amortized cost and is classified as a Level 3 measurement.

[3] Fair value represents net offsets to debt resulting from adjustments from interest rate swaps entered into to hedge certain debt at Power. Carrying amount represents such fair value reduced by the unamortized premium resulting from a debt exchange entered into between Power and Energy Holdings.