Balance Sheet Details - Depreciation and Amortization Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Apr. 24, 2015	Apr. 25, 2014	Apr. 26, 2013
Depreciation, Depletion and Amortization [Abstract]
Depreciation and amortization expense	$ 243.5	$ 275.0	$ 258.8

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Name:	us-gaap_DepreciationDepletionAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration