STOCK-BASED COMPENSATION - Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Nov. 29, 2020	Nov. 24, 2019	Nov. 29, 2020	Nov. 24, 2019
Compensation expense
Stock-settled compensation expense	$ 5.3	$ 7.2	$ 11.3	$ 12.6
Cash-settled RSUs				1.0
Total compensation expense	5.3	7.2	11.3	13.6
Income tax benefit	(0.9)	(1.4)	(2.0)	(2.6)
Total compensation expense, net of tax benefit	4.4	5.8	9.3	11.0
Stock-settled restricted stock units
Compensation expense
Stock-settled compensation expense	3.2	3.5	6.7	6.3
Performance shares
Compensation expense
Stock-settled compensation expense	$ 2.1	$ 3.7	$ 4.6	6.2
Stock options
Compensation expense
Stock-settled compensation expense				$ 0.1

Allocated Share-based Compensation Expense, Cash-settled Restricted Stock Units

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Allocated Share-based Compensation Expense, Stock-settled Compensation Expense

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Amount, after tax, of expense for award under share-based payment arrangement.

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

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