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Debt (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
Debt (Narrative) (Details) - USD ($)	May 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jul. 31, 2021
Debt Instrument [Line Items]
Repayments of debt	$ 2,500,000,000
Interest payments		$ 433,000,000	$ 459,000,000	$ 434,000,000
Credit facility, maximum borrowing capacity		5,000,000,000
Commercial Paper
Debt Instrument [Line Items]
Commercial paper outstanding		0
Credit Facility \| 364-day Committed Bank Credit Facility due March 2021
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity		$ 2,000,000,000
Debt instrument term		364 days
Credit Facility \| Multi Year Facility Expiring March 2023
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity		$ 2,000,000,000
Credit Facility \| Multi-year Facility Expiring March 2025
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity		$ 1,000,000,000
Notes
Debt Instrument [Line Items]
Debt issued	$ 1,500,000,000				$ 500,000,000