Financial Assets & Liabilities - Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financial assets and financial liabilities measured at fair value on a recurring basis:
Debt securities - current	$ 600	$ 696
Potential reduction in net position of total derivative assets	213	194
Potential reduction in net position of total derivative liabilities	213	194
Recurring
Financial assets and financial liabilities measured at fair value on a recurring basis:
Cash equivalents	8,316	4,819
Total assets	9,161	5,823
Total liabilities	627	673
Recurring \| Prepaid expenses and other current assets
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivative assets	85	149
Recurring \| Investments and sundry assets
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivative assets	151	94
Recurring \| Other accrued expenses and liabilities
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivative liabilities	587	167
Recurring \| Other liabilities
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivative liabilities	40	506
Recurring \| Level 1
Financial assets and financial liabilities measured at fair value on a recurring basis:
Equity investments	2	0
Recurring \| Level 1 \| Money market funds
Financial assets and financial liabilities measured at fair value on a recurring basis:
Cash equivalents	148	427
Recurring \| Level 2
Financial assets and financial liabilities measured at fair value on a recurring basis:
Debt securities - current	600	696
Debt securities - noncurrent	7	65
Recurring \| Level 2 \| Interest rate contracts
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivatives designated as hedging - Assets	100	56
Recurring \| Level 2 \| Foreign exchange contracts
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivatives designated as hedging - Assets	111	175
Derivatives designated as hedging - Liabilities	580	635
Derivatives not designated as hedging - Assets	13	10
Derivatives not designated as hedging - Liabilities	47	33
Recurring \| Level 2 \| Time deposits and certificates of deposit
Financial assets and financial liabilities measured at fair value on a recurring basis:
Cash equivalents	7,668	4,392
Recurring \| Level 2 \| U.S. government securities
Financial assets and financial liabilities measured at fair value on a recurring basis:
Cash equivalents	500
Recurring \| Level 1 And 2 \| Equity contracts
Financial assets and financial liabilities measured at fair value on a recurring basis:
Derivatives not designated as hedging - Assets	$ 12	1
Derivatives not designated as hedging - Liabilities		$ 4

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

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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 of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset, deducted from derivative assets.

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Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

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Aggregate fair value of all derivative liabilities designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

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Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as an asset.

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Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset, deducted from derivative liabilities.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Fair value of financial and nonfinancial obligations.

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