Long-Term Debt (Schedule of Long-term Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Aug. 19, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal Amount	$ 5,302		$ 3,620
Unamortized Discount and Debt Issuance Costs	(105)		(54)
Net Long-term Debt	5,197		3,566
Long-term Debt, Current Maturities	(268)		0
Debt Instrument Unamortized Discount Premium and Debt Issuance Cost Net Excluding Current Maturities	(105)		(54)
Long term Debt Gross Excluding Current Maturities	5,034		3,620
Long-term debt, net of current portion	$ 4,929		3,566
Senior Notes \| 3.60% Senior Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate (percent)	3.60%
Principal Amount	$ 250		250
Unamortized Discount and Debt Issuance Costs	0		(1)
Net Long-term Debt	250		249
Debt Instrument Unamortized Discount Premium and debt issuance cost net Current Maturities	0		0
Long Term Debt Gross Current Maturities	(250)		0
Long-term Debt, Current Maturities	$ (250)		0
Senior Notes \| 0.875% Senior Notes Due 2024
Debt Instrument [Line Items]
Stated interest rate (percent)	0.875%	0.875%
Principal Amount	$ 300		0
Unamortized Discount and Debt Issuance Costs	(2)		0
Net Long-term Debt	$ 298		0
Senior Notes \| 3.6% Senior Notes Due 2026
Debt Instrument [Line Items]
Stated interest rate (percent)	3.60%
Principal Amount	$ 750		750
Unamortized Discount and Debt Issuance Costs	(6)		(6)
Net Long-term Debt	744		744
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
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	$ 811		859
Unamortized Discount and Debt Issuance Costs	(9)		(10)
Net Long-term Debt	$ 802		849
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	(4)		(4)
Net Long-term Debt	$ 296		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%	2.875%
Principal Amount	$ 350		0
Unamortized Discount and Debt Issuance Costs	(11)		0
Net Long-term Debt	$ 339		0
Senior Notes \| 5.0% Senior Notes Due 2046
Debt Instrument [Line Items]
Stated interest rate (percent)	5.00%
Principal Amount	$ 700		700
Unamortized Discount and Debt Issuance Costs	(22)		(23)
Net Long-term Debt	$ 678		677
Senior Notes \| 4.375% Senior Notes Due 2047
Debt Instrument [Line Items]
Stated interest rate (percent)	4.375%
Principal Amount	$ 500		500
Unamortized Discount and Debt Issuance Costs	(8)		(9)
Net Long-term Debt	$ 492		491
Senior Notes \| 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate (percent)	8.73%
Principal Amount	$ 24		0
Unamortized Discount and Debt Issuance Costs			0
Net Long-term Debt	24		0
Debt Instrument Unamortized Discount Premium and debt issuance cost net Current Maturities	0		0
Long Term Debt Gross Current Maturities	(18)		0
Long-term Debt, Current Maturities	$ (18)		0
Senior Notes \| Term Loan Due 2026
Debt Instrument [Line Items]
Stated interest rate (percent)	0.20%
Principal Amount	$ 6		0
Unamortized Discount and Debt Issuance Costs	0		0
Net Long-term Debt	$ 6		0
Senior Notes \| 3.125% Senior Notes Due 2051
Debt Instrument [Line Items]
Stated interest rate (percent)	3.125%	3.125%
Principal Amount	$ 600		0
Unamortized Discount and Debt Issuance Costs	(23)		0
Net Long-term Debt	$ 577		0
Senior Notes \| 3.75% Senior Notes Due 2061
Debt Instrument [Line Items]
Stated interest rate (percent)	3.375%	3.375%
Principal Amount	$ 450		0
Unamortized Discount and Debt Issuance Costs	(19)		0
Net Long-term Debt	$ 431		$ 0

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

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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