COMMON STOCK AND STOCK-BASED COMPENSATION - Narrative (Details) - Two Thousand Fourteen Stock Plan - USD ($) $ in Millions	3 Months Ended
Jul. 28, 2018	Jul. 29, 2017
Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Multiplier - Threshold Performance	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, EBITDA Goal, Percentage of Likelihood	70.00%
Multiplier - Target Performance	100.00%
Multiplier - Maximum Performance	150.00%
Restricted Stock Awards (RSAs) \| Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 1.0	$ 1.5
Restricted Stock Awards (RSAs) \| Independent directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 0.9
Number of shares issued (in shares)	24,000
Time-Based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected expense	$ 18.0
Compensation expense	$ 0.1	$ 1.5
Time-Based Restricted Stock Units (RSUs) \| Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded (in shares)	7,750
Granted (in shares)	646,675
Outstanding (in shares)	346,897
Time-Based Restricted Stock Units (RSUs) \| Percentage Vesting on April 28, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	30.00%
Time-Based Restricted Stock Units (RSUs) \| Percentage Vesting on April 27, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	30.00%
Time-Based Restricted Stock Units (RSUs) \| Percentage Vesting on May 2, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	40.00%
2020 EBITDA Threshold Performance \| Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares represented (in shares)	350,043
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, EBITDA Goal	$ 198.9
Expected expense	$ 11.9
2020 EBITDA Target Performance \| Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares represented (in shares)	700,086
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, EBITDA Goal	$ 221.0
2020 EBITDA Maximum Performance \| Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares represented (in shares)	1,050,128
2020 EBITDA Maximum Performance \| Restricted Stock Awards (RSAs) \| Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded (in shares)	11,625

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Multiplier - Target Performance

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Multiplier - Threshold Performance

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, EBITDA Goal

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, EBITDA Goal, Percentage of Likelihood

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Total Aggregate Grants Under the Plan

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The total compensation expense to be recorded over the vesting period.

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Shared-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance-based Shares to be Issued

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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 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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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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Number of share instruments newly issued under a share-based compensation plan.

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Percentage of vesting of share-based compensation awards.

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