Property and Equipment, Net - Components of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 369,182	$ 365,029
Less: Accumulated depreciation	(101,081)	(98,472)
Total property and equipment, net	268,101	266,557
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	21,434	20,624
Software [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	35,163	34,937
Land [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	89,130	89,130
Building and Building Improvements [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	203,659	203,873
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	10,524	10,321
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 9,272	$ 6,144