Fixed Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total fixed assets	$ 46,471	$ 39,660
Less: Accumulated depreciation and amortization	(25,682)	(23,415)
Fixed assets, net	20,789	16,245
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total fixed assets	37,200	29,029
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total fixed assets	3,058	3,683
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total fixed assets	$ 6,213	$ 6,948