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Marketable and Other Securities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Marketable Securities [Line Items]
Sale proceeds from investments classified as available-for-sale and sold prior to maturity	$ 476	$ 535	$ 1,400	$ 1,600
Lyft, Inc. [Member] | Interest Income and Other Non-Operating Income [Member] | Other current assets [Member]
Marketable Securities [Line Items]
Unrealized gain (loss) on securities		$ (291)		$ (71)

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Amount of unrealized gain (loss) recognized in income from asset (liability) measured at fair value on recurring basis using unobservable input (level 3) and still held.

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Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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