Geographic And Customer Information (Comparison Of Geographic Revenues) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 965,087	$ 873,592	$ 771,978
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	585,201	530,111	472,700
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	169,767	135,084	109,680
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	129,664	130,648	116,999
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 80,455	$ 77,749	$ 72,599