Certain Balance Sheet Accounts - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Total property and equipment	$ 92,449	$ 84,956
Less accumulated depreciation	(62,512)	(62,951)
Total property and equipment, net	29,937	22,005
Computers and Equipment [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	18,337	18,621
Computer Software [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	30,812	31,276
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	10,365	8,449
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	$ 32,935	$ 26,610