Derivatives and Hedging Activities - Schedule of Derivative Instruments Not Designated as Cash Flow Hedges (Detail) (Foreign Exchange Forward Contracts, USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Oct. 25, 2013	Oct. 26, 2012	Oct. 25, 2013	Oct. 26, 2012
Foreign Exchange Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign currency exchange forward contracts	$ 0.6	$ (9.7)	$ 0.8	$ 6.2

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration