Supplementary Financial Information (Schedule Of Supplemental Cash Flow Information) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014
Supplementary Financial Information [Abstract]
Interest	$ 177	$ 178
Capitalized interest	(3)	(3)
Interest	174	175
Federal		144
State	22	20
Total amount is lieu of income taxes	22	164
Noncash construction expenditures	$ 61	$ 37

Income Taxes Paid, Federal

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- Definition

Income Taxes Paid, State

+ References

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- Definition

Future cash outflow to pay for construction in progress expenditures that have occurred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

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Amount of interest capitalized during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Allowance for Funds Used during Construction

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-Name Accounting Standards Codification

-Topic 835

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The amount of cash paid for interest during the period.

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The amount of cash paid for interest during the period net of cash paid for interest that is capitalized.

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