PROPERTY AND EQUIPMENT, NET - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 585,183	$ 541,452
Less: Accumulated depreciation and amortization	(282,936)	(259,312)
Property and equipment, net	302,247	282,140
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	215,870	208,228
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	192,964	174,004
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	132,215	116,827
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 44,134	$ 42,393