INVESTMENTS - Narrative (Details) $ in Millions		1 Months Ended		3 Months Ended	12 Months Ended
		Dec. 31, 2021 USD ($)	May 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Feb. 22, 2022	Jun. 30, 2021	Aug. 31, 2019 USD ($)
Schedule of Investments [Line Items]
Impairment of investment	[1]				$ 0	$ 100	$ 0
Trip.com Group
Schedule of Investments [Line Items]
Proceeds from sale of equity securities						525
Equity securities, net realized loss						201
Equity securities, net unrealized gains							141
Trip.com Group | Long-term Investments
Schedule of Investments [Line Items]
Investment in equity securities						655
Meituan
Schedule of Investments [Line Items]
Equity securities, net unrealized gains						2,000	$ 602
Payments to acquire other investments									$ 450
Equity securities, net unrealized loss					731
Meituan | Subsequent Event
Schedule of Investments [Line Items]
Market price, percent decrease										24.00%
Meituan | Long-term Investments
Schedule of Investments [Line Items]
Equity securities, noncurrent		$ 2,300			2,300	3,100
Didi Chuxing
Schedule of Investments [Line Items]
Payments to acquire other investments								$ 500
ADS to common stock conversion ratio											0.25
Equity securities, net unrealized loss					205
Didi Chuxing | Subsequent Event
Schedule of Investments [Line Items]
Market price, percent decrease										15.00%
Didi Chuxing | Long-term Investments
Schedule of Investments [Line Items]
Equity securities, noncurrent		195			195
Grab
Schedule of Investments [Line Items]
Equity securities, net unrealized gains					101
Grab | Subsequent Event
Schedule of Investments [Line Items]
Market price, percent decrease										27.00%
Grab | Long-term Investments
Schedule of Investments [Line Items]
Equity securities, noncurrent		301			301
Investments in private companies accounted for as debt securities						200
Yanolja Co., Ltd
Schedule of Investments [Line Items]
Equity securities without readily determinable fair value, upward price adjustment, annual amount					255
Government and corporate debt securities
Schedule of Investments [Line Items]
Cash realized from the sales and maturities of investments in debt securities						2,200
Convertible debt securities | Trip.com Group
Schedule of Investments [Line Items]
Investment in debt securities		500	$ 250		500	525						$ 500
Proceeds from maturities of debt securities		500	$ 250
Convertible debt securities | Trip.com Group | Long-term Investments
Schedule of Investments [Line Items]
Investment in debt securities						25
Investments in private companies accounted for as debt securities						24
Convertible debt securities | Trip.com Group | Short-term Investments
Schedule of Investments [Line Items]
Investment in debt securities		25			25	500
Investments in private companies accounted for as debt securities		25			25	$ 501
Convertible debt securities | Trip.com Group, Convertible Senior Note, September 2016 | Short-term Investments
Schedule of Investments [Line Items]
Term of available-for-sale debt securities						6 years
Convertible debt securities | Trip.com Group, Convertible Senior Note, December 2015 | Short-term Investments
Schedule of Investments [Line Items]
Term of available-for-sale debt securities						10 years
Investments in private companies, equity securities | Long-term Investments
Schedule of Investments [Line Items]
Fair value of investment in equity securities of private companies		325			325	$ 455
Investment in equity securities of private companies		66			66	552
Investments in private companies, equity securities | Didi Chuxing | Long-term Investments
Schedule of Investments [Line Items]
Fair value of investment in equity securities of private companies				$ 400		400
Impairment of investment				$ 100
Investments in private companies, equity securities | Yanolja Co., Ltd | Long-term Investments
Schedule of Investments [Line Items]
Fair value of investment in equity securities of private companies		306			306
Investment in equity securities of private companies		$ 51			$ 51	$ 51
Redeemable convertible preferred stock | Grab
Schedule of Investments [Line Items]
Payments to acquire other investments								$ 200

[1] See Note 5 for additional information related to the net (losses) gains on equity securities and impairment of investment.