Stock-based Compensation - Summary of Stock Options (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Apr. 27, 2019 USD ($) $ / shares shares
Number of Options
Beginning balance (in shares) \| shares	1,206
Granted (in shares) \| shares	621
Exercised (in shares) \| shares	(1)
Canceled (in shares) \| shares	(270)
Ending balance (in shares) \| shares	1,556
Vested or expected to vest at end of year (in shares) \| shares	1,418
Exercisable at end of year (in shares) \| shares	282
Weighted- Average Exercise Price
Beginning balance (in usd per share) \| $ / shares	$ 50.82
Granted (in usd per share) \| $ / shares	23.40
Exercised (in usd per share) \| $ / shares	19.85
Canceled (in usd per share) \| $ / shares	50.41
Ending balance (in usd per share) \| $ / shares	39.96
Vested or expected to vest at end of year (in usd per share) \| $ / shares	38.84
Exercisable at end of year (in usd per share) \| $ / shares	$ 49.05
Aggregate Intrinsic Value
Balance at end of year \| $	$ 0
Vested or expected to vest at end of year \| $	0
Exercisable at end of year \| $	$ 0

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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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For presentations that combine terminations, 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 or that expired.

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Weighted average price of options that were either forfeited or expired.

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Net number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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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 per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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

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