Income Taxes (Schedule Of Effective Tax Rates) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Line Items]
Effective tax rate	38.90%	36.50%	35.50%	36.30%
PSE And G [Member]
Income Taxes [Line Items]
Effective tax rate	38.80%	36.10%	37.40%	36.10%
Power [Member]
Income Taxes [Line Items]
Effective tax rate	41.90%	39.30%	37.90%	39.40%