Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Debt (Narrative) (Details) - USD ($)			1 Months Ended					3 Months Ended
Debt (Narrative) (Details) - USD ($)	Apr. 15, 2021	Apr. 02, 2021	Dec. 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Jan. 31, 2020	Oct. 31, 2018	Mar. 31, 2021	Mar. 31, 2020	Apr. 09, 2021	Apr. 08, 2021	May 31, 2020
Debt Instrument [Line Items]
Commercial paper outstanding								$ 0
Proceeds from lines of credit								0	$ 2,000,000,000
Other Debt Facilities
Debt Instrument [Line Items]
Long-term line of credit			$ 0					0
Debt instrument, unused borrowing capacity			573,000,000					$ 517,000,000
2.250% Senior Debt Obligations Due 2030
Debt Instrument [Line Items]
Interest rate								2.25%
Commercial Paper \| Subsequent Event
Debt Instrument [Line Items]
Short-term debt										$ 2,000,000,000.0	$ 1,500,000,000
Revolving Credit Facility \| New Facility \| Subsequent Event
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity		$ 2,800,000,000
Term of debt		5 years
Revolving Credit Facility \| Old Facility and 364-day Facility
Debt Instrument [Line Items]
Long-term line of credit								$ 0
Revolving Credit Facility \| Old Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity								$ 1,800,000,000
Term of debt							5 years
Revolving Credit Facility \| 364-day Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity				$ 1,000,000,000
Term of debt				364 days
Term Loan Facility \| $500 Million One-Year Term Loan and $500 Million Two-Year Term Loan
Debt Instrument [Line Items]
Proceeds from lines of credit									$ 1,000,000,000
Term Loan Facility \| $500 Million One-Year Term Loan Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity						$ 500,000,000
Term of debt						1 year
Term Loan Facility \| $500 Million Two-Year Term Loan Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity						$ 500,000,000
Term of debt						2 years
Senior Notes
Debt Instrument [Line Items]
Repayments of debt			700,000,000		$ 500,000,000
Senior Notes \| Subsequent Event
Debt Instrument [Line Items]
Repayments of debt	$ 500,000,000
Senior Notes \| 2.250% Senior Debt Obligations Due 2030
Debt Instrument [Line Items]
Debt instrument face amount												$ 750,000,000
Floating Rate Notes
Debt Instrument [Line Items]
Repayments of debt			$ 300,000,000