Segment Information (Schedule of Fixed Assets by Geographic Location) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 246,262	$ 183,514
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	202,833	136,203
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	27,218	28,261
Other Geographic Locations [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 16,211	$ 19,050