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FAIR VALUE MEASUREMENTS - Summary of Classification of Equity Securities (Details) - Other Equity Securities - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total	$ 4,721	$ 6,970
Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Marketable equity securities	2,216	4,361
Prepaid and other current assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Marketable equity securities	797	853
Other long-term assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Marketable equity securities	$ 1,708	$ 1,756

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

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