Segment Information (Revenues By Geographic Location) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net revenues	$ 672,899	$ 589,495
Infrastructure [Member]
Net revenues	535,333	468,762
Infrastructure [Member] | Americas [Member]
Net revenues	296,434	252,483
Infrastructure [Member] | EMEA [Member]
Net revenues	174,402	160,071
Infrastructure [Member] | Asia-Pacific [Member]
Net revenues	64,497	56,208
SaaS [Member]
Net revenues	137,566	120,733
SaaS [Member] | Americas [Member]
Net revenues	116,230	103,227
SaaS [Member] | EMEA [Member]
Net revenues	16,743	14,455
SaaS [Member] | Asia-Pacific [Member]
Net revenues	$ 4,593	$ 3,051