Financial Risk Management Activities (Schedule Providing Credit Risk From Others, Net Of Collateral) (Detail) (Power [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 Counterparty
Derivative [Line Items]
Credit exposure, percentage	97.00%
Current Exposure	$ 345
Securities held as Collateral	14
Net Credit Exposure With Counterparties After Applying Collateral	345
Number of Counterparties greater than 10%	1
Net Exposure of Counterparties greater than 10%	251
Number of active counterparties on credit risk derivatives	154
Investment Grade - External Rating [Member]
Derivative [Line Items]
Current Exposure	331
Securities held as Collateral	14
Net Credit Exposure With Counterparties After Applying Collateral	331
Number of Counterparties greater than 10%	1
Net Exposure of Counterparties greater than 10%	251	[1]
Non-Investment Grade - External Rating [Member]
Derivative [Line Items]
Current Exposure	1
Securities held as Collateral	0
Net Credit Exposure With Counterparties After Applying Collateral	1
Number of Counterparties greater than 10%	0
Net Exposure of Counterparties greater than 10%	0
Investment Grade - No External Rating [Member]
Derivative [Line Items]
Current Exposure	6
Securities held as Collateral	0
Net Credit Exposure With Counterparties After Applying Collateral	6
Number of Counterparties greater than 10%	0
Net Exposure of Counterparties greater than 10%	0
Non-Investment Grade - No External Rating [Member]
Derivative [Line Items]
Current Exposure	7
Securities held as Collateral	0
Net Credit Exposure With Counterparties After Applying Collateral	7
Number of Counterparties greater than 10%	0
Net Exposure of Counterparties greater than 10%	$ 0

[1] Represents net exposure with PSE&G.