Financial Risk Management Activities (Schedule Providing Credit Risk From Others, Net Of Collateral) (Detail) - Power [Member] $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) Counterparty
Derivative [Line Items]
Current Exposure	$ 257
Securities held as Collateral	16
Net exposure	241
Number of Counterparties greater than 10%	$ 1
Number Of Active Counterparties On Credit Risk Derivatives | Counterparty	145
Investment Grade - External Rating [Member]
Derivative [Line Items]
Percentage Of Credit Exposure	99.00%
Investment Grade [Member]
Derivative [Line Items]
Current Exposure	$ 255
Securities held as Collateral	15
Net exposure	240
Number of Counterparties greater than 10%	1
Amount Of Net Credit Exposure Greater Than Ten Percent	166	[1]
External Credit Rating, Non Investment Grade [Member]
Derivative [Line Items]
Current Exposure	2
Securities held as Collateral	1
Amount Of Net Credit Exposure Greater Than Ten Percent	0
Non-Investment Grade [Member]
Derivative [Line Items]
Net exposure	1
Number of Counterparties greater than 10%	0
Cash [Member]
Derivative [Line Items]
Securities held as Collateral	1
Letter of Credit [Member]
Derivative [Line Items]
Securities held as Collateral	$ 15

[1] Represents net exposure of $166 million with PSE&G.