Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 4,868	$ 5,180
3.60% Senior Notes Due 2022 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 0	250
Stated interest rate (percent)	3.60%
0.875% Senior Notes Due 2024 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 298	298
Stated interest rate (percent)	0.875%
3.6% Senior Notes Due 2026 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 745	745
Stated interest rate (percent)	3.60%
Loan related to tax-exempt waste disposal revenue bonds due 2027 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 11	11
1.625% Senior Notes Due 2029 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 725	786
Stated interest rate (percent)	1.625%
3.375% Senior Notes Due 2030 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 297	296
Stated interest rate (percent)	3.375%
3.50% Senior Notes Due 2032 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 249	249
Stated interest rate (percent)	3.50%
2.875% Senior Notes Due 2041 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 339	339
Stated interest rate (percent)	2.875%
5.0% Senior Notes Due 2046 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 679	678
Stated interest rate (percent)	5.00%
4.375% Senior Notes Due 2047 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 492	492
Stated interest rate (percent)	4.375%
3.125% Senior Notes Due 2051 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 577	577
Stated interest rate (percent)	3.125%
3.375% 2061 Senior Notes | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 431	431
Stated interest rate (percent)	3.375%
8.73% Senior Notes Due 2022 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 10	19
Stated interest rate (percent)	8.73%
Term Loan Due 2026 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 15	9
Fair Value | 3.60% Senior Notes Due 2022 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	0	252
Fair Value | 0.875% Senior Notes Due 2024 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	286	287
Fair Value | 3.6% Senior Notes Due 2026 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	733	805
Fair Value | Loan related to tax-exempt waste disposal revenue bonds due 2027 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	11	11
Fair Value | 1.625% Senior Notes Due 2029 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	620	824
Fair Value | 3.375% Senior Notes Due 2030 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	271	319
Fair Value | 3.50% Senior Notes Due 2032 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	238	271
Fair Value | 2.875% Senior Notes Due 2041 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	248	339
Fair Value | 5.0% Senior Notes Due 2046 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	659	885
Fair Value | 4.375% Senior Notes Due 2047 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	432	592
Fair Value | 3.125% Senior Notes Due 2051 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	420	582
Fair Value | 3.375% 2061 Senior Notes | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	305	432
Fair Value | 8.73% Senior Notes Due 2022 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	10	19
Fair Value | Term Loan Due 2026 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	$ 15	$ 9