Segment Information (Schedule Of Financial Information By Reportable Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 27, 2012	Jul. 28, 2012	Apr. 28, 2012	Jan. 28, 2012	Oct. 29, 2011	Jul. 30, 2011	Apr. 30, 2011	Jan. 29, 2011	Oct. 27, 2012	Oct. 29, 2011	Oct. 30, 2010
Segment Reporting Information [Line Items]
Net revenues	$ 578,357	$ 555,332	$ 543,439	$ 560,642	$ 550,472	$ 502,850	$ 548,364	$ 545,756	$ 2,237,770	$ 2,147,442	$ 2,091,153
Cost of revenues									854,751	863,908	860,033
Gross margin	360,690	340,478	337,082	344,769	327,515	306,527	328,609	320,883	1,383,019	1,283,534	1,231,120
SAN Products
Segment Reporting Information [Line Items]
Net revenues									1,356,099	1,237,994	1,240,626
Cost of revenues									362,608	356,013	394,506
Gross margin									993,491	881,981	846,120
IP Networking Products
Segment Reporting Information [Line Items]
Net revenues									534,757	551,820	488,188
Cost of revenues									327,248	321,183	288,980
Gross margin									207,509	230,637	199,208
Global Services
Segment Reporting Information [Line Items]
Net revenues									346,914	357,628	362,339
Cost of revenues									164,895	186,712	176,547
Gross margin									$ 182,019	$ 170,916	$ 185,792