Stockholders' Equity - Summary of Activities Related to Stock Repurchase Program (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended	143 Months Ended
Apr. 24, 2015	Apr. 25, 2014	Apr. 26, 2013	Apr. 24, 2015
Equity [Abstract]
Number of shares repurchased	29.6	47.3	18.1	214.0
Average price per share	$ 39.30	$ 39.78	$ 32.68	$ 33.48
Aggregate purchase price	$ 1,165.2	$ 1,881.5	$ 590.0
Remaining authorization at end of period	$ 2,459.5	$ 1,124.8	$ 1,406.3	$ 2,459.5

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Number of shares that have been repurchased and retired during the period.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

+ Details

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- Definition

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

+ References

+ Details

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

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