EMPLOYEE BENEFIT PLANS AND OTHER POST-RETIREMENT BENEFITS - Pension Cost Financial Statement Presentation (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 26, 2018	Aug. 27, 2017
Pension Plans
Employee Benefit Plans and Other Post-retirement Benefits
Pension cost incurred	$ 2.1	$ 1.9
Pension Plans | Cost of sales
Employee Benefit Plans and Other Post-retirement Benefits
Pension cost incurred	2.1	$ 1.9
Post-Retirement Plan
Employee Benefit Plans and Other Post-retirement Benefits
Pension cost incurred	0.1
Post-Retirement Plan | Selling, general and administrative
Employee Benefit Plans and Other Post-retirement Benefits
Pension cost incurred	$ 0.1