Financial Risk Management Activities (Schedule Providing Credit Risk From Others, Net Of Collateral) (Detail) - Power [Member] $ in Millions	Jun. 30, 2016 USD ($)
Derivative [Line Items]
Current Exposure	$ 365
Securities held as Collateral	130
Net exposure	235
Number of Counterparties greater than 10%	2
Amount Of Net Credit Exposure Greater Than Ten Percent	125
Investment Grade - External Rating [Member]
Derivative [Line Items]
Current Exposure	334
Securities held as Collateral	129
Net exposure	205
Number of Counterparties greater than 10%	2
Amount Of Net Credit Exposure Greater Than Ten Percent	125	[1]
Non-Investment Grade - External Rating [Member]
Derivative [Line Items]
Current Exposure	20
Securities held as Collateral	0
Net exposure	20
Number of Counterparties greater than 10%	0
Amount Of Net Credit Exposure Greater Than Ten Percent	0
Investment Grade - No External Rating [Member]
Derivative [Line Items]
Current Exposure	8
Securities held as Collateral	1
Net exposure	7
Number of Counterparties greater than 10%	0
Amount Of Net Credit Exposure Greater Than Ten Percent	0
Non-Investment Grade - No External Rating [Member]
Derivative [Line Items]
Current Exposure	3
Securities held as Collateral	0
Net exposure	3
Number of Counterparties greater than 10%	0
Amount Of Net Credit Exposure Greater Than Ten Percent	0
Cash [Member]
Derivative [Line Items]
Securities held as Collateral	3
Letter of Credit [Member]
Derivative [Line Items]
Securities held as Collateral	$ 127

[1] Represents net exposure of $94 million with PSE&G. The remaining net exposure of $31 million is with a non-affiliated power purchaser which is an investment grade counterparty.