Debt And Related Expenses (Schedule Of Debt Instruments and Balances) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Net discount on debentures and notes	$ (20)	$ (20)
Debt issuance costs	(34)	(35)
Total long-term debt	4,295	4,294
5.85% due December 15, 2025 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 485	$ 485
Debt, maturity date	Dec. 15, 2025
Debt interest rate, stated percentage	5.85%	5.85%
7.50% due September 15, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 73	$ 73
Debt, maturity date	Sep. 15, 2027
Debt interest rate, stated percentage	7.50%	7.50%
7.875% due September 30, 2031 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 675	$ 675
Debt, maturity date	Sep. 30, 2031
Debt interest rate, stated percentage	7.875%	7.875%
7.95% due April 15, 2032 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 366	$ 366
Debt, maturity date	Apr. 15, 2032
Debt interest rate, stated percentage	7.95%	7.95%
5.60% due July 15, 2041 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,250	$ 1,250
Debt, maturity date	Jul. 15, 2041
Debt interest rate, stated percentage	5.60%	5.60%
4.75% due May 15, 2042 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 750	$ 750
Debt, maturity date	May 15, 2042
Debt interest rate, stated percentage	4.75%	4.75%
5.00% due June 15, 2045 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 750	$ 750
Debt, maturity date	Jun. 15, 2045
Debt interest rate, stated percentage	5.00%	5.00%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount, after accumulated amortization, of debt discount.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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