Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment	$ 129,286	$ 115,185
Less -- accumulated depreciation	72,344	61,989
Total	56,942	53,196
Furniture, fixtures and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	14,956	14,445
Computer and related equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	23,286	33,121
Computer Software, Intangible Asset [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	72,852	52,929
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	12,670	10,551
Work-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 5,522	$ 4,139