Segment Information (Revenues By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 662,677	$ 658,773
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	662,677	658,773
Operating Segments [Member] | Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	391,346	388,686
Operating Segments [Member] | EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	201,852	206,931
Operating Segments [Member] | Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 69,479	$ 63,156