Property and Equipment, Net - Summary of Property and Equipment, Net (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment	$ 377,109	$ 330,401
Less accumulated depreciation and amortization	(72,782)	(61,239)
Property and equipment, net	304,327	269,162
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	13,419	13,294
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	4,784	3,439
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	182,746	180,945
Equipment Under Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	5,310	5,310
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	26,945	24,930
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	59,013	55,734
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	23,713	22,124
Internally Developed Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	13,466	11,039
Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	1,099	1,099
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 46,614	$ 12,487