Fair Value Measurements, Other Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financial assets
Cash and cash equivalents, at carrying amount	$ 3,313	$ 2,583
Financial liabilities
Debt (excluding finance leases), at carrying amount	13,013	8,881
Fair Value, Inputs, Level 1 [Member]
Financial assets
Cash and cash equivalents, at fair value	3,313	2,583
Fair Value, Inputs, Level 2 [Member]
Financial liabilities
Debt (excluding finance leases), at fair value	$ 15,103	$ 10,583

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

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-Publisher FASB
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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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