Geographic And Customer Information (Comparison Of Property And Equipment, Net, By Geographic Region) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 333,861	$ 327,136
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	323,564	319,513
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	9,450	7,211
APAC [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 847	$ 412