Segment Information (Schedule of Fixed Assets by Geographic Location) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 166,636	$ 163,860
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	104,939	93,951
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	39,976	48,043
Other Geographic Locations [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 21,721	$ 21,866