Property And Equipment (Property And Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 187,960	$ 147,673
Less: Accumulated depreciation and amortization	(119,866)	(90,231)
Total property and equipment, net	68,094	57,442
Computers and related equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	173,103	135,360
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,928	1,710
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 12,929	$ 10,603