Fair Value Measurements (Schedule Of Carrying And Fair Values Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2022	May 14, 2022	Dec. 31, 2021	Jul. 17, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	$ 4,879		$ 5,180
Senior Notes | 3.60% Senior Notes Due 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.60%	3.60%
Carrying Value	$ 0		250
Senior Notes | 0.875% 2024 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	0.875%
Carrying Value	$ 299		298
Senior Notes | 3.60% Senior Notes Due 2026
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.60%
Carrying Value	$ 746		745
Senior Notes | Loan related to tax-exempt waste disposal revenue bonds due 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	$ 11		11
Senior Notes | 1.625% Senior Notes Due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	1.625%
Carrying Value	$ 743		786	$ 779
Senior Notes | 3.375 Senior Notes Due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.375%
Carrying Value	$ 297		296
Senior Notes | 3.50% Senior Notes Due 2032
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.50%
Carrying Value	$ 249		249
Senior Notes | 2.875% Senior Notes Due 2041
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	2.875%
Carrying Value	$ 339		339
Senior Notes | 5.00% 2046 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	5.00%
Carrying Value	$ 679		678
Senior Notes | 4.375% 2047 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	4.375%
Carrying Value	$ 492		492
Senior Notes | 3.125% 2051 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.125%
Carrying Value	$ 578		577
Fair Value			582
Senior Notes | 3.375% 2061 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	3.375%
Carrying Value	$ 431		431
Fair Value			432
Senior Notes | 8.73% 2022 RS Cogen Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	8.73%
Carrying Value	$ 0		19
Senior Notes | 2026 Term Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate (percent)	0.20%
Carrying Value	$ 15		9
Fair Value | Senior Notes | 3.60% Senior Notes Due 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	0		252
Fair Value | Senior Notes | 0.875% 2024 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	279		287
Fair Value | Senior Notes | 3.60% Senior Notes Due 2026
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	705		805
Fair Value | Senior Notes | 1.625% Senior Notes Due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	606		824
Fair Value | Senior Notes | 3.375 Senior Notes Due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	258		319
Fair Value | Senior Notes | 3.50% Senior Notes Due 2032
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	233		271
Fair Value | Senior Notes | 2.875% Senior Notes Due 2041
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	231		339
Fair Value | Senior Notes | 5.00% 2046 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	583		885
Fair Value | Senior Notes | 4.375% 2047 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	379		592
Fair Value | Senior Notes | 3.125% 2051 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	373
Fair Value | Senior Notes | 3.375% 2061 Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	267
Fair Value | Senior Notes | 8.73% 2022 RS Cogen Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	0		19
Fair Value | Senior Notes | 2026 Term Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	15		9
Fair Value | Loan related to tax-exempt waste disposal revenue bonds due 2027 | Loan related to tax-exempt waste disposal revenue bonds due 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	$ 11		$ 11