Employee Compensation Plans Employee Compensation Plans (Narrative) (Details) (USD $)	12 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Oct. 30, 2010
2009 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award
Additional shares authorized under plan	35,000,000
Shares authorized for issuance under plan	83,000,000
Maximum number of shares to be added to the plan	40,300,000
2009 Director Plan
Share-based Compensation Arrangement by Share-based Payment Award
Shares authorized for issuance under plan	2,000,000
Maximum number of shares to be added to the plan	900,000
2009 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Additional shares authorized under plan	30,000,000
Shares authorized for issuance under plan	65,000,000
Shares available for issuance under plan	38,700,000
Maximum payroll deductions	15.00%
Discount from Market Price At Offering Date	85.00%
Maximum number of shares to be purchased per employee	3,750
Plan Offering Period	24 months
Plan Purchase Period	6 months
Number of purchase periods	4
Equity Compensation Plans
Share-based Compensation Arrangement by Share-based Payment Award
Shares authorized for issuance under plan	126,700,000	100,600,000
Shares available for issuance under plan	76,000,000	26,500,000
Reduction In Number Of Shares Available For Issuance	1.56
Minimum Percentage Holding Requirement For Principal Shareholder	10.00%
Minimum Fair Market Value Of The Shares Granted To Principal Shareholder	110.00%
Expiration Date For Stock Options And Stock Appreciation Rights Maximum Time From Grant Date - 10% owners	5 years
Expiration Date For Stock Options And Stock Appreciation Rights Maximum Time From Grant Date	7 years
Award vesting period (years), minimum	3
Award vesting period (years), maximum	4
1999 Nonstatutory Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Shares reserved for issuance under director plan	51,400,000
Shares Remaining For Future Issuance	5,200,000
Mcdata Equity Plans
Share-based Compensation Arrangement by Share-based Payment Award
Shares authorized for issuance under plan	1,600,000
Employee 401 K Plan
Share-based Compensation Arrangement by Share-based Payment Award
Company's matching contributions to the 401(k) Plan	$ 9,100,000	$ 9,300,000	$ 8,700,000
Maximum contribution by employee	$ 3,000
Employee contribution maximum rate	60.00%