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Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2022	May 14, 2022	Dec. 31, 2021	Jul. 17, 2019	Nov. 30, 2017	Aug. 10, 2016	Jul. 31, 2012
Debt Instrument [Line Items]
Principal Amount	$ 4,976		$ 5,283
Unamortized Discount and Debt Issuance Costs	(97)		(103)
Net Long-Term Debt	4,879		5,180
Net Long-Term Debt, Current portion	0		(269)
Principal Amount, Net of current portion	4,976		5,014
Unamortized Discount and Debt Issuance Costs, Net of current portion	(97)		(103)
Net Long-Term Debt, Net of current portion	$ 4,879		4,911
Senior Notes \| 3.60% Senior Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate (percent)	3.60%	3.60%
Principal Amount	$ 0		250				$ 250
Unamortized Discount and Debt Issuance Costs	0		0
Net Long-Term Debt	0		250
Principal Amount, Current portion	0		(250)
Unamortized Discount and Debt Issuance Costs, Current portion	0		0
Net Long-Term Debt, Current portion	$ 0		(250)
Senior Notes \| 0.875% 2024 Senior Notes
Debt Instrument [Line Items]
Stated interest rate (percent)	0.875%
Principal Amount	$ 300		300
Unamortized Discount and Debt Issuance Costs	(1)		(2)
Net Long-Term Debt	$ 299		298
Senior Notes \| 3.60% Senior Notes Due 2026
Debt Instrument [Line Items]
Stated interest rate (percent)	3.60%
Principal Amount	$ 750		750			$ 750
Unamortized Discount and Debt Issuance Costs	(4)		(5)
Net Long-Term Debt	746		745
Senior Notes \| Loan related to tax-exempt waste disposal revenue bonds due 2027
Debt Instrument [Line Items]
Principal Amount	11		11
Unamortized Discount and Debt Issuance Costs	0		0
Net Long-Term Debt	$ 11		11
Senior Notes \| 1.625% Senior Notes Due 2029
Debt Instrument [Line Items]
Stated interest rate (percent)	1.625%
Principal Amount	$ 750		794
Unamortized Discount and Debt Issuance Costs	(7)		(8)
Net Long-Term Debt	$ 743		786	$ 779
Senior Notes \| 3.375 Senior Notes Due 2030
Debt Instrument [Line Items]
Stated interest rate (percent)	3.375%
Principal Amount	$ 300		300
Unamortized Discount and Debt Issuance Costs	(3)		(4)
Net Long-Term Debt	$ 297		296
Senior Notes \| 3.50% Senior Notes Due 2032
Debt Instrument [Line Items]
Stated interest rate (percent)	3.50%
Principal Amount	$ 250		250
Unamortized Discount and Debt Issuance Costs	(1)		(1)
Net Long-Term Debt	$ 249		249
Senior Notes \| 2.875% Senior Notes Due 2041
Debt Instrument [Line Items]
Stated interest rate (percent)	2.875%
Principal Amount	$ 350		350
Unamortized Discount and Debt Issuance Costs	(11)		(11)
Net Long-Term Debt	$ 339		339
Senior Notes \| 5.00% 2046 Senior Notes
Debt Instrument [Line Items]
Stated interest rate (percent)	5.00%
Principal Amount	$ 700		700			$ 700
Unamortized Discount and Debt Issuance Costs	(21)		(22)
Net Long-Term Debt	$ 679		678
Senior Notes \| 4.375% 2047 Senior Notes
Debt Instrument [Line Items]
Stated interest rate (percent)	4.375%
Principal Amount	$ 500		500		$ 500
Unamortized Discount and Debt Issuance Costs	(8)		(8)
Net Long-Term Debt	$ 492		492
Senior Notes \| 3.125% 2051 Senior Notes
Debt Instrument [Line Items]
Stated interest rate (percent)	3.125%
Principal Amount	$ 600		600
Unamortized Discount and Debt Issuance Costs	(22)		(23)
Net Long-Term Debt	$ 578		577
Senior Notes \| 3.375% 2061 Senior Notes
Debt Instrument [Line Items]
Stated interest rate (percent)	3.375%
Principal Amount	$ 450		450
Unamortized Discount and Debt Issuance Costs	(19)		(19)
Net Long-Term Debt	$ 431		431
Senior Notes \| 8.73% 2022 RS Cogen Debt
Debt Instrument [Line Items]
Stated interest rate (percent)	8.73%
Principal Amount	$ 0		19
Unamortized Discount and Debt Issuance Costs	0		0
Net Long-Term Debt	0		19
Principal Amount, Current portion	0		(19)
Unamortized Discount and Debt Issuance Costs, Current portion	0		0
Net Long-Term Debt, Current portion	$ 0		(19)
Senior Notes \| 2026 Term Loans
Debt Instrument [Line Items]
Stated interest rate (percent)	0.20%
Principal Amount	$ 15		9
Unamortized Discount and Debt Issuance Costs	0		0
Net Long-Term Debt	$ 15		$ 9