Property and Equipment (Capital Lease Obligations) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 89,022	$ 70,361
Less: accumulated depreciation and amortization	(51,027)	(38,943)
Property and equipment, net	37,995	31,418
Capital leases	41,321	24,242
Accumulated depreciation, capital leases	21,066	11,982
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	60,673	39,570
Computer software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,764	10,773
Office equipment and furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,156	4,570
Automobiles [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,644	1,329
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 15,785	$ 14,119