Financial Risk Management Activities (Schedule Providing Credit Risk From Others, Net Of Collateral) (Detail) $ in Millions		Jun. 30, 2015 USD ($)
Power [Member]
Derivative [Line Items]
Current Exposure		$ 322
Securities held as Collateral		82
Net exposure		314
Number of Counterparties greater than 10%		2
Amount Of Net Credit Exposure Greater Than Ten Percent		119
Power [Member] | Investment Grade - External Rating [Member]
Derivative [Line Items]
Current Exposure		310
Securities held as Collateral		82
Net exposure		302
Number of Counterparties greater than 10%		2
Amount Of Net Credit Exposure Greater Than Ten Percent	[1]	119
Power [Member] | Non-Investment Grade - External Rating [Member]
Derivative [Line Items]
Current Exposure		2
Securities held as Collateral		0
Net exposure		2
Number of Counterparties greater than 10%		0
Amount Of Net Credit Exposure Greater Than Ten Percent		0
Power [Member] | Investment Grade - No External Rating [Member]
Derivative [Line Items]
Current Exposure		10
Securities held as Collateral		0
Net exposure		10
Number of Counterparties greater than 10%		0
Amount Of Net Credit Exposure Greater Than Ten Percent		0
Power [Member] | Non-Investment Grade - No External Rating [Member]
Derivative [Line Items]
Current Exposure		0
Securities held as Collateral		0
Net exposure		0
Number of Counterparties greater than 10%		0
Amount Of Net Credit Exposure Greater Than Ten Percent		0
PSE And G [Member] | Investment Grade - External Rating [Member]
Derivative [Line Items]
Net exposure		$ 82

[1] net exposure of $82 million with PSE&G.