Commitments And Contingent Liabilities (Regulatory Proceedings and Superstorm Sandy) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Loss Contingencies [Line Items]
Clean Energy Program, current portion	$ 86		$ 142
PSE And G [Member]
Loss Contingencies [Line Items]
Clean Energy Program, current portion	86		$ 142
Power [Member] | FERC Compliance [Domain]
Loss Contingencies [Line Items]
Loss Contingency related to bidding errors		$ 25
Nuclear Electric Insurance Limited Ii Salem Hope Creek Peach Bottom [Member] | Total Site Coverage [Member]
Loss Contingencies [Line Items]
Property Damage Primary Layer	1,500
Property Damage Excess Layers	300
Nuclear Electric Insurance Limited Ii Salem Hope Creek Peach Bottom [Member] | Total Site Coverage for Non Nuclear Event [Member]
Loss Contingencies [Line Items]
Property Damage Excess Layers	300
Nuclear Electric Insurance Limited I Peach Bottom [Member] | Total Site Coverage [Member]
Loss Contingencies [Line Items]
Property Damage Excess Layers	300
Nuclear Electric Insurance Limited I Peach Bottom [Member] | Total Site Coverage for Non Nuclear Event [Member]
Loss Contingencies [Line Items]
Property Damage Excess Layers	$ 600