Income Taxes - Statutory Federal Income Tax Rate (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Apr. 24, 2015	Apr. 25, 2014	Apr. 26, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax computed at federal statutory rate	$ 249.5	$ 259.2	$ 198.3
State income taxes, net of federal benefit	5.4	5.6	(2.0)
Foreign earnings in lower tax jurisdictions	(141.0)	(163.3)	(144.4)
Stock-based compensation	5.5	9.8	18.4
Research and experimentation credits	(13.7)	(8.7)	(12.1)
Resolution of income tax examinations	46.4	0	0.1
Other	0.8	0.6	3.0
Provision for income taxes	$ 152.9us-gaap_IncomeTaxExpenseBenefit	$ 103.2us-gaap_IncomeTaxExpenseBenefit	$ 61.3us-gaap_IncomeTaxExpenseBenefit

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

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

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Number 210

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority noncontrolling interest income (loss), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, increase (decrease) in enacted tax rate, prior year income taxes, increase (decrease) in deferred tax asset valuation allowance, and other adjustments.

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