Business Combinations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			0 Months Ended	1 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended
	Jan. 27, 2012	Jan. 28, 2011	Jan. 27, 2012	Jan. 28, 2011	May 06, 2011 LSI Corporation [Member]	May 13, 2010 Bycast [Member]	Nov. 30, 2011 Bycast [Member]	May 06, 2011 Engenio External Storage Systems Business [Member]	Jan. 27, 2012 Engenio External Storage Systems Business [Member]	Jan. 27, 2012 Engenio External Storage Systems Business [Member]	Jan. 28, 2011 Engenio External Storage Systems Business [Member]
Business Acquisition [Line Items]
Acquisition dates						May 13,2010		May 6, 2011
Business acquisition cash paid					$ 480.0	$ 80.5
Business acquisition purchase price allocation warranty receivable					13.0
Net revenues	1,565.5	1,289.6	4,530.7	3,694.3					178.3	517.8
Adjustment reflected in unaudited pro forma condensed combined information										5.6	(5.6)
Charges related to the combined business	6.7		6.7						0.7	0.7
Release of remaining purchase price from escrow							13.1
Adjustments	$ 1.2		$ 1.2