Segment Information (Revenues By Geographic Location) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Net revenues	$ 730,384	$ 615,210	$ 1,403,283	$ 1,204,705
Infrastructure [Member]
Segment Reporting Information [Line Items]
Net revenues	586,526	489,700	1,121,859	958,462
Infrastructure [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net revenues	322,911	259,769	619,345	512,252
Infrastructure [Member] | EMEA [Member]
Segment Reporting Information [Line Items]
Net revenues	191,015	163,976	365,417	324,047
Infrastructure [Member] | Asia-Pacific [Member]
Segment Reporting Information [Line Items]
Net revenues	72,600	65,955	137,097	122,163
SaaS [Member]
Segment Reporting Information [Line Items]
Net revenues	143,858	125,510	281,424	246,243
SaaS [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net revenues	120,680	106,784	236,910	210,011
SaaS [Member] | EMEA [Member]
Segment Reporting Information [Line Items]
Net revenues	18,001	15,578	34,744	30,033
SaaS [Member] | Asia-Pacific [Member]
Segment Reporting Information [Line Items]
Net revenues	$ 5,177	$ 3,148	$ 9,770	$ 6,199