Common Share Purchase Right Per Common Share, Ratio

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Common Share Rights Exercise, Period, Option One

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Common Share Rights Exercise, Period, Option Two

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Aggregate number of common shares reserved for future issuance.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Amount of cash inflow from exercise of option under share-based payment arrangement.

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Percentage of subsidiary's or equity investee's stock owned by parent company after stock transaction.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Discount rate from fair value on offering date that participants pay for shares.

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Discount rate from fair value on purchase date that participants pay for shares.

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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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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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Price of a single share of a number of saleable stocks of a company.

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Shareholders' Equity and Share-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	May 02, 2020 USD ($) $ / shares shares	Apr. 27, 2019 USD ($) shares	Apr. 28, 2018 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized	120,000,000
Common purchase right per common stock	1
Share price \| $ / shares	$ 25
Days following ownership announcement option one	10 days
Percentage of ownership	20.00%
Days following ownership announcement, option two	10 days
Shares available for grant	1,176,000
Weighted-average period for unrecognized costs	2 years 10 months 8 days
Exercisable at end of year, Shares	1,593,000
Exercised, aggregate intrinsic value \| $	$ 0	$ 98	$ 65
Fair value of vested options \| $	$ 566	$ 667	$ 977
Stock issued for ESPP	453,000	241,000	223,000
Nonvested unrecognized compensation expense \| $	$ 3,096
Proceeds from exercise of stock options \| $	0	$ 1,318	$ 519
Tax benefit from share based payments \| $	$ (92)	(52)	9
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award life	10 years
Vesting period	5 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Weighted-average period for unrecognized costs	2 years 8 months 22 days
Fair value \| $	$ 1,415	$ 1,530	$ 1,274
Restricted Stock and Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs \| $	$ 2,197
In The Money Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (usd per share) \| $ / shares	$ 4.45
Exercisable at end of year, Shares	0
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Shares available for grant	4,000,000
Requisite service period	6 months
Employee maximum contribution percentage	15.00%
Percentage of purchase price at the lower of the fair market value	85.00%
Purchase discount percentage	15.00%
Shares reserved for future issuance	979,000
Independent Directors \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award life	7 years
Vesting period	1 year
Independent Directors \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized	115,000,000
Undesignated Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized	5,000,000
Series A Junior Participating Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common purchase right per common stock	0.001