Property and Equipment - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 366,400	$ 363,532
Less accumulated depreciation	(97,516)	(94,093)
Total property and equipment, net	268,884	269,439
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	28,839	27,046
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	89,130	89,130
Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	197,606	197,689
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,529	10,494
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,355	8,071
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 31,941	$ 31,102