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Equity Securities, FV-NI, Cost Of Securities Sold

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Equity Securities, FV-NI, Reclassified From Long-Term To Short-Term In Period

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Cost of Equity Secuirites without readily determinable fair value

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Proceeds from Sale of Equity Securities, FV-NI

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Weighted maturity of investments

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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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Amortized cost 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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Amount 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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Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

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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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Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

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

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

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

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Amount of investment in equity security without readily determinable fair value.

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Amount of cumulative impairment loss on investment in equity security without readily determinable fair value.

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Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings and other comprehensive loss (OCI).

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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INVESTMENTS - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
INVESTMENTS - Narrative (Details) - USD ($) $ in Millions	May 07, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Weighted average life of all fixed income investments, excluding the Company's investment in Ctrip convertible debt securities		9 months 18 days
Net (losses) gains on marketable equity securities		$ (307)	$ 451
Cost of investment				$ 501
Corporate debt securities
Schedule of Investments [Line Items]
Impairment of debt securities		3
Corporate debt securities \| Subsequent Event
Schedule of Investments [Line Items]
Proceeds from the maturity of debt securities	$ 164
Trip.com Group
Schedule of Investments [Line Items]
Cost basis of securities sold		124
Proceeds from sale of securities		94
Loss on sale of securities		40
Unrealized loss on securities held		178
Net (losses) gains on marketable equity securities			360
Trip.com Group \| Subsequent Event
Schedule of Investments [Line Items]
Cost basis of securities sold	531
Proceeds from sale of securities	$ 431
Trip.com Group \| Trip.com Group convertible debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes		775
Meituan-Dianping [Member]
Schedule of Investments [Line Items]
Fair value of equity securities		972		1,100
Net (losses) gains on marketable equity securities		(81)	$ 91
Payments to acquire investments					$ 450
Long-term Investments \| Corporate debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes				963
Carrying Value				963
Total unrealized losses included in other comprehensive income				2
Long-term Investments \| Investment in private company equity securities
Schedule of Investments [Line Items]
Cost of investment		501		501
Equity Securities without Readily Determinable Fair Value, Impairment Loss, Cumulative Amount		100		0
Investment in equity securities without readily determinable FV		401		501
Long-term Investments \| Redeemable Convertible Preferred Stock [Member]
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes		250
Carrying Value		230		250
Long-term Investments \| Trip.com Group
Schedule of Investments [Line Items]
Cost of investment in equity securities				655
Fair value of equity securities				726
Long-term Investments \| Trip.com Group \| Trip.com Group convertible debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes		525		775
Carrying Value		448		767
Total unrealized losses included in other comprehensive income		77		8
Long-term Investments \| Trip.com Group 1.25% Notes due 2022 \| Trip.com Group convertible debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes						$ 25
Long-term Investments \| Didi Chuxing \| Investment in private company equity securities
Schedule of Investments [Line Items]
Cost of investment				500
Investment in equity securities without readily determinable FV		400
Long-term Investments \| Grab \| Redeemable Convertible Preferred Stock [Member]
Schedule of Investments [Line Items]
Carrying Value		180		200
Total unrealized losses included in other comprehensive income		20
Short-term Investments \| Corporate debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes		164		751
Carrying Value		164		751
Total unrealized losses included in other comprehensive income		0		$ 1
Short-term Investments \| Trip.com Group convertible debt securities
Schedule of Investments [Line Items]
Investments in debt securities reclassified from long-term to short term		103
Short-term Investments \| Trip.com Group
Schedule of Investments [Line Items]
Investments in ADS reclassified from long-term to short term		414
Short-term Investments \| Trip.com Group \| Trip.com Group convertible debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes		250
Carrying Value		248
Total unrealized losses included in other comprehensive income		2
Short-term Investments \| Trip.com Group 1% Note Due 2020 [Member] \| Trip.com Group convertible debt securities
Schedule of Investments [Line Items]
Cost of Trip.com Group convertible notes		$ 250