PROPERTY AND EQUIPMENT - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 346	$ 256	$ 231
Property and equipment, net	1,904	1,956
International Operations
Property, Plant and Equipment [Line Items]
Property and equipment, net	695	533
Reimbursed Expenses
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 121	$ 147	$ 126
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	40 years