EMPLOYEE BENEFIT PLANS AND OTHER POST-RETIREMENT BENEFITS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 26, 2018	Aug. 27, 2017
Pension Plans
Components of net periodic benefit cost for our pension and postretirement benefit plans
Service cost	$ 2.1	$ 1.9
Interest cost	0.2	0.1
Expected return on plan assets	(0.2)	(0.1)
Net periodic benefit cost	2.1	$ 1.9
Post-Retirement Plan
Components of net periodic benefit cost for our pension and postretirement benefit plans
Interest cost	0.1
Actuarial loss	0.2
Net periodic benefit cost	$ 0.3