Fair Value Measurements (Schedule Of Quantitative Information About Level 3 Fair Value Measurements) (Detail) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	$ 6		$ 7
Liabilities, Fair Value	0		(1)
PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value			0
Liabilities, Fair Value			(5)
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	6		7
Liabilities, Fair Value	0		(6)
Various [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	1		0	[1]
Liabilities, Fair Value	0		0	[1]
Electric Load Contracts [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	5		7
Liabilities, Fair Value	$ 0		$ (1)
Valuation Technique (s)	Discounted Cash flow	Discounted Cash Flow
Significant Unobservable Inputs	Historic Load Variability	Historic Load Variability
Electric Load Contracts [Member] | Minimum [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Historic Load Variability	10.00%		10.00%
Electric Load Contracts [Member] | Maximum [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Historic Load Variability	0.00%		0.00%
Natural Gas Supply Contracts [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value			$ 0
Liabilities, Fair Value			$ (5)
Valuation Technique (s)		Discounted Cash Flow
Significant Unobservable Inputs		Transportation Costs
Natural Gas Supply Contracts [Member] | Minimum [Member] | MWh [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transportation Costs			0.60
Natural Gas Supply Contracts [Member] | Maximum [Member] | MWh [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transportation Costs			0.80

[1] Includes gas positions which were immaterial.