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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | 4 Months Ended | 12 Months Ended
--- | --- | ---
Apr. 21, 2018 | Apr. 22, 2017 | Dec. 30, 2017
Income Tax Disclosure [Abstract] |  |  |
Effective income tax rate | 27.70% | 32.80% |
Federal statutory rate | 21.00% | 35.00% |
Provisional discrete income tax benefit, re-measurement of deferred income tax assets and liabilities |  |  | $ 26.0
Federal return due date | Oct. 15, 2018 |  |

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- Definition Amount of income tax expense for remeasurement of deferred tax asset from change in tax rate pursuant to Tax Cuts and Jobs Act. + References No definition available. + Details
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