PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,127	$ 1,909
Less: Accumulated depreciation	(1,305)	(1,153)
Property and equipment, net	822	756
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 728	746
Computer equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	2 years
Computer equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	6 years
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 742	565
Capitalized software | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	2 years
Capitalized software | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 268	278
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	1 year
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	15 years
Office equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 61	63
Office equipment, furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	2 years
Office equipment, furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	8 years
Building construction-in-progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 328	$ 257