Pension And OPEB (Schedule Of Pension And OPEB Costs) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	$ 1	$ 14
Pension Benefits [Member] | PSE And G [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	(1)	7
Pension Benefits [Member] | Power [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	0	4
Pension Benefits [Member] | Other Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	2	3
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	22	18
OPEB [Member] | PSE And G [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	14	11
OPEB [Member] | Power [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	7	6
OPEB [Member] | Other Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Benefit Costs	$ 1	$ 1