Fixed Assets - Textual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation	$ 22,293	$ 18,871	$ 16,462
Capital Lease Obligations
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	1,967	1,959
Capital leases, lessee balance sheet, assets by major class, accumulated depreciation	$ 1,316	$ 1,378