Fair Value Measurements (Schedule Of Quantitative Information About Level 3 Fair Value Measurements) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	$ 3		$ 12
Liabilities, Fair Value	(1)		(1)
PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	7		26
Liabilities, Fair Value	0		0
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	10		38
Liabilities, Fair Value	(1)		(1)
Various [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	0	[1]	0	[2]
Liabilities, Fair Value	0	[1]	0	[2]
Electric Load Contracts [Member] | Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	3		12
Liabilities, Fair Value	(1)		(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%
Forward Contracts [Member] | PSE And G [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value	7		26
Liabilities, Fair Value	$ 0		$ 0
Valuation Technique (s)	Discounted Cash Flow		Discounted Cash Flow
Significant Unobservable Inputs	Transportation Costs		Transportation Costs
Forward 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	0.70		0.70
Forward 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	1		1

[1] Includes long-term electric positions which were immaterial as of March 31, 2015.

[2] Includes gas supply positions and long-term electric capacity positions which were immaterial as of December 31, 2014.