Fixed Assets - Schedule of Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Cost	$ 160,111	$ 155,323
Accumulated Depreciation	(96,554)	(95,083)
Net Book Value	63,557	60,240
Computers, furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Cost	87,213	91,272
Accumulated Depreciation	(62,901)	(65,451)
Net Book Value	24,312	25,821
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Cost	72,898	64,051
Accumulated Depreciation	(33,653)	(29,632)
Net Book Value	$ 39,245	$ 34,419