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Stockholders Equity - Number and Value of Shares Netted for Employee Taxes (Detail) (Restricted Stock Units, USD $)
In Millions, unless otherwise specified |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
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Oct. 26, 2012
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Oct. 28, 2011
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Oct. 26, 2012
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Oct. 28, 2011
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Restricted Stock Units
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Shares withheld for taxes | 0.1 | 0.1 | 0.7 | 0.6 |
| Fair value of shares withheld and retired | $ 2.8 | $ 2.5 | $ 22.6 | $ 27.8 |