Share Based Compensation - Summary of Share-Based Compensation Activity (Detail) - Jul. 18, 2015 - $ / shares	Total
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Under Options, Outstanding, Beginning balance	494,483
Shares Under Options, Exercised/Vested	(109,401)
Shares Under Options, Cancelled/Forfeited	(63)
Shares Under Options, Outstanding, Ending balance	385,019
Shares Under Options, Vested and expected to vest in the future at April 25, 2015	385,019
Shares Under Options, Exercisable	385,019
Weighted Average Exercise Price, Option outstanding, Beginning balance	$ 20.61
Weighted Average Exercise Price, Exercised/Vested	21.95
Weighted Average Exercise Price, Cancelled/Forfeited	11.50
Weighted Average Exercise Price, Options outstanding, Ending balance	20.23
Weighted Average Exercise Price, Vested and expected to vest in the future at April 25, 2015	20.23
Weighted Average Exercise Price, Exercisable	$ 20.23
Restricted Stock Awards, Outstanding, Beginning balance	600,653
Restricted Stock Awards, Granted	312,050
Restricted Stock Awards, Exercised/Vested	(265,737)
Restricted Stock Awards, Cancelled/Forfeited	(7,890)
Restricted Stock Awards, Outstanding, Ending balance	639,076
Weighted Average Grant-Date Fair Value, Beginning balance	$ 23.08
Weighted Average Grant-Date Fair Value, Granted	26.56
Weighted Average Grant-Date Fair Value, Exercised/Vested	19.30
Weighted Average Grant-Date Fair Value, Cancelled/Forfeited	21.98
Weighted Average Grant-Date Fair Value, Ending balance	$ 24.73

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Number of share options (or share units) exercised during the current period.

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