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Marketable and Other Securities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Marketable Securities [Line Items]
Sale proceeds from investments classified as available-for-sale and sold prior to maturity	$ 366	$ 611
Lyft, Inc. [Member] \| Level 1 [Member] \| Other current assets [Member]
Marketable Securities [Line Items]
Fair value of equity securities			$ 535
Lyft, Inc. [Member] \| Level 3 [Member] \| Interest Income and Other Non-Operating Income [Member]
Marketable Securities [Line Items]
Unrealized gain (loss) on securities		$ 285