Debt And Related Expenses (Schedule Of Debt Instruments and Balances) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Net premium on debentures and notes	$ 49	$ 64
Debt issuance costs	(30)	(30)
Total debt	6,140	6,155
Less amount classified as short-term debt	475	483
Long-term debt	5,665	5,672
5.25% due September 15, 2024 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 472	$ 472
Charge on early retirement of debt, cash retirement costs	5.25%	5.25%
Debt, maturity date	Sep. 15, 2024
5.85% due December 15, 2025 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 485	$ 485
Charge on early retirement of debt, cash retirement costs	5.85%	5.85%
Debt, maturity date	Dec. 15, 2025
7.50% due September 15, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 73	$ 73
Charge on early retirement of debt, cash retirement costs	7.50%	7.50%
Debt, maturity date	Sep. 15, 2027
5.25% due October 15, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 390	$ 390
Charge on early retirement of debt, cash retirement costs	5.25%	5.25%
Debt, maturity date	Oct. 15, 2027
5.875% due June 15, 2028 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 325	$ 325
Charge on early retirement of debt, cash retirement costs	5.875%	5.875%
Debt, maturity date	Jun. 15, 2028
4.50% due January 15, 2030 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 585	$ 585
Charge on early retirement of debt, cash retirement costs	4.50%	4.50%
Debt, maturity date	Jan. 15, 2030
7.875% due September 30, 2031 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 675	$ 675
Charge on early retirement of debt, cash retirement costs	7.875%	7.875%
Debt, maturity date	Sep. 30, 2031
7.95% due April 15, 2032 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 366	$ 366
Charge on early retirement of debt, cash retirement costs	7.95%	7.95%
Debt, maturity date	Apr. 15, 2032
5.60% due July 15, 2041 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,250	$ 1,250
Charge on early retirement of debt, cash retirement costs	5.60%	5.60%
Debt, maturity date	Jul. 15, 2041
4.75% due May 15, 2042 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 750	$ 750
Charge on early retirement of debt, cash retirement costs	4.75%	4.75%
Debt, maturity date	May 15, 2042
5.00% due June 15, 2045 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 750	$ 750
Charge on early retirement of debt, cash retirement costs	5.00%	5.00%
Debt, maturity date	Jun. 15, 2045