Property and Equipment, Net - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, cost	$ 702,949	$ 695,008
Accumulated depreciation	(581,991)	(566,623)
Property and equipment, net	120,958	128,385
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment, cost	164,131	164,547
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, cost	294,143	291,681
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, cost	90,083	88,136
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, cost	$ 154,592	$ 150,644