Commitments And Contingent Liabilities (Regulatory Proceedings) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Costs recognized in Operation and Maintenance Expense		$ 2,869	$ 3,008	$ 2,978
Insured Event, Gain (Loss)				28
PSE&G [Member]
Loss Contingencies [Line Items]
Costs recognized in Operation and Maintenance Expense		1,434	1,475	1,560
Insured Event, Gain (Loss)				0
Power [Member]
Loss Contingencies [Line Items]
Costs recognized in Operation and Maintenance Expense		1,038	$ 1,143	1,057
Insured Event, Gain (Loss)				$ 28
Power [Member] | Regulatory Agency [Domain]
Loss Contingencies [Line Items]
Loss Contingency, Loss in Period	$ 25	10
Maximum [Member] | Power [Member] | Regulatory Agency [Domain]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss		135
Minimum [Member] | Power [Member] | Regulatory Agency [Domain]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss		$ 35