Regulatory Assets And Liabilities (Components Of Regulatory Assets And Liabilities) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Regulatory Assets And Liabilities [Line Items]
Carrying Amount, Regulatory Assets	$ 1,995	$ 2,023
Carrying Amount, Regulatory Liabilities	674	594
Net regulatory asset	1,321	1,429
Bondco
Regulatory Assets And Liabilities [Line Items]
Net regulatory asset	$ 47	108
Estimated Net Removal Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Life of utility plant
Carrying Amount, Regulatory Liabilities	$ 608	531
Investment Tax Credit and Protected Excess Deferred Taxes [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Various
Carrying Amount, Regulatory Liabilities	$ 15	18
Over Collection of Transition Bond Revenues [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	1 year
Carrying Amount, Regulatory Liabilities	$ 31	32
Net regulatory asset	$ 31	32
Energy Efficiency Programs [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Not applicable
Carrying Amount, Regulatory Liabilities	$ 20	13
Generation Related Regulatory Assets Securitized by Transition Bonds [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	1 year
Carrying Amount, Regulatory Assets	$ 81	148
Net regulatory asset	$ 78	140
Employee Retirement Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	5 years
Carrying Amount, Regulatory Assets	$ 47	55
Employee Retirement Costs to be Reviewed [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	To be determined
Carrying Amount, Regulatory Assets	$ 267	246
Employee Retirement Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	To be determined
Carrying Amount, Regulatory Assets	$ 828	865
Self Insurance Reserve (Primarily Storm Recovery Costs) - Net [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	5 years
Carrying Amount, Regulatory Assets	$ 111	127
Self Insurance Reserve to be Reviewed [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	To be determined
Carrying Amount, Regulatory Assets	$ 316	242
Securities Reacquisition Costs (Pre-Industry Restructure) [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	2 years
Carrying Amount, Regulatory Assets	$ 19	23
Securities Reacquisition Costs (Post Industry Restructure) - Net [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Terms of related debt
Carrying Amount, Regulatory Assets	$ 8	7
Recoverable Amounts In Lieu Of Deferred Income Taxes - Net [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Life of related asset or liability
Carrying Amount, Regulatory Assets	$ 12	14
Deferred Conventional Meter And Metering Facilities Depreciation [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Largely 5 years
Carrying Amount, Regulatory Assets	$ 112	123
Deferred AMS Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	To be determined
Carrying Amount, Regulatory Assets	$ 140	113
Energy Efficiency Performance Bonus [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	1 year
Carrying Amount, Regulatory Assets	$ 11	22
Under Recovered Wholesale Transmission Service Expense - Net [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	1 year
Carrying Amount, Regulatory Assets	$ 34	26
Other Regulatory Assets [Member]
Regulatory Assets And Liabilities [Line Items]
Remaining Rate Recovery/Amortization Period	Various
Carrying Amount, Regulatory Assets	$ 9	$ 12