Fair Value Measurements (Fair Value Of Debt) (Detail) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount		$ 10,697	$ 9,568
Long-Term Debt, Fair Value		12,284	10,256
Power - Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	[1]	2,381	2,237
Long-Term Debt, Fair Value	[1]	2,788	2,508
PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	[1]	7,816	6,821
Long-Term Debt, Fair Value	[1]	8,996	7,235
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	[2]	0	7
Long-Term Debt, Fair Value	[2]	0	7
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	[3]	500	503
Long-Term Debt, Fair Value	[3]	$ 500	$ 506

[1] Given that most bonds do not trade, the fair value amounts of taxable debt securities (primarily Level 2 measurements) are generally determined by a valuation model that is based on a conventional discounted cash flow methodology and utilizes assumptions of current market pricing curves. In order to incorporate the credit risk into the discount rates, pricing is obtained (i.e. U.S. Treasury rate plus credit spread) based on expected new issue pricing across each of the companies’ respective debt maturity spectrum. The credit spreads of various tenors obtained from this information are added to the appropriate benchmark U.S. Treasury rates in order to determine the current market yields for the various tenors. The yields are then converted into discount rates of various tenors that are used for discounting the respective cash flows of the same tenor for each bond or note.

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

[3] Fair value includes a $500 million floating rate term loan and net offsets to debt resulting from adjustments from interest rate swaps entered into to hedge certain debt at Power. The fair value of the term loan debt (Level 2 measurement) was considered to be equal to the carrying value because the interest payments are based on LIBOR rates that are reset monthly. Carrying amount includes such fair value reduced by the unamortized premium resulting from a debt exchange entered into between Power and Energy Holdings.