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Marketable and Other Securities - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Marketable Securities [Line Items]
Sales proceeds from investments classified as available-for-sale and sold prior to maturity	$ 4,500	$ 4,300	$ 5,600
Lyft, Inc. | Level 3 | Interest Income and Other Non-Operating Income
Marketable Securities [Line Items]
Unrealized gain (loss) on securities		142
Other current assets | Lyft, Inc. | Level 1
Marketable Securities [Line Items]
Fair value of equity securities	$ 535
Other assets | Lyft, Inc. | Level 3
Marketable Securities [Line Items]
Fair value of equity securities		$ 884

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