Stock Purchase and Award Plans , Valuation Assumptions (Details) - $ / shares	12 Months Ended
Apr. 24, 2015	Apr. 25, 2014	Apr. 26, 2013
Fair Value Assumptions Used in Black-Scholes Model
Weighted average fair value of options granted (per share)	$ 25.39	$ 12.00	$ 7.42
Expected life (years)	4 years 2 months 27 days	6 years 4 months 24 days	6 years 6 months
Risk-free interest rate	0.99%	1.88%	0.94%
Volatility	21.29%	25.20%	26.22%
Dividend yield	1.66%	2.02%	2.64%

No definition available.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

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-Subparagraph (f)(2)(iii)

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

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

-Publisher FASB

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

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

-Publisher FASB

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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

-Publisher FASB

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-Subparagraph (d)(1)

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

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