Goodwill And Other Intangible Assets, Net (Identified Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	Apr. 27, 2012	Apr. 29, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 358.4	$ 86.4
Accumulated Amortization	(122.4)	(33.4)
Other Intangible Assets, Net	236.0	53.0
Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	282.1	66.1
Accumulated Amortization	(79.0)	(23.2)
Other Intangible Assets, Net	203.1	42.9
Customer Contracts/Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	59.4	12.0
Accumulated Amortization	(32.7)	(4.6)
Other Intangible Assets, Net	26.7	7.4
Trademarks And Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	14.7	7.7
Accumulated Amortization	(9.7)	(5.5)
Other Intangible Assets, Net	5.0	2.2
Covenants Not To Compete [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2.2	0.6
Accumulated Amortization	(1.0)	(0.1)
Other Intangible Assets, Net	$ 1.2	$ 0.5