Regulatory Matters (Components Of Regulatory Assets And Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	$ 1,571	$ 1,547
Total regulatory liabilities	2,892	2,876
Net regulatory assets (liabilities)	(1,321)	(1,329)
Estimated Net Removal Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory liabilities	1,370	1,348
Excess Deferred Taxes [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory liabilities	1,425	1,442
Over-Recovered Wholesale Transmission Service Expense [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory liabilities	6	7
Unamortized Gain On Reacquisition Of Debt [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory liabilities	26	26
Employee Retirement Costs Over-recovered Since Last Rate Review Period [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory liabilities	45	39
Other Regulatory Liabilities [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory liabilities	20	14
Employee Retirement Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	323	328
Employee Retirement Costs Being Amortized [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	183	193
Employee Retirement Costs Incurred Since The Last Rate Review Period [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	97	99
Self-Insurance Reserve (Primarily Storm Recovery Costs) Being Amortized [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	213	223
Self-Insurance Reserve Incurred Since The Last Rate Review Period (Primarily Storm Related) [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	429	373
Debt Reacquisition Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	18	19
Under-recovered AMS Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	123	128
Energy Efficiency Performance Bonus [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	23	31
Wholesale Distribution Substation Service [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	81	75
Unrecovered Expenses Related To COVID-19 [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	35	35
Recoverable Deferred Income Taxes - Net [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	17	16
Uncollectible Payments From REPs [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	9	9
Other Regulatory Assets [Member]
Regulatory Assets And Liabilities [Line Items]
Total regulatory assets	$ 20	$ 18