SEGMENTS - Geographic Information (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2022		Mar. 31, 2021	Mar. 31, 2024		Mar. 31, 2023		Dec. 31, 2021
Segment Information
Revenue	$ 4,431	[1]	$ 4,771	$ 16,052	[1]	$ 17,026	[1]	$ 18,657	[1]
Property and equipment, net				2,674		2,779
Operating right-of-use assets, net				864		964
United States.
Segment Information
Revenue	1,169			4,295		4,726		4,805
Property and equipment, net				951		922
Operating right-of-use assets, net				113		124
Japan.
Segment Information
Revenue	706			2,344		2,502		2,923
Operating right-of-use assets, net				73		110
Other countries, excluding United States and Japan
Segment Information
Revenue	$ 2,556			9,413		9,797		$ 10,930
Belgium
Segment Information
Operating right-of-use assets, net				135		149
Italy
Segment Information
Operating right-of-use assets, net				95		64
Other countries excluding United States
Segment Information
Property and equipment, net				1,724		1,857
Other countries excluding United States, Japan, Belgium, and Italy
Segment Information
Operating right-of-use assets, net				$ 448		$ 517

[1] Including related-party revenue of $287 for the year ended March 31, 2023, $236 for the three months ended March 31, 2022, and $704 for the year ended December 31, 2021