LONG-TERM DEBT AND REVOLVING CREDIT FACILITY (Net Interest Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2016	Feb. 22, 2015	Feb. 28, 2016	Feb. 22, 2015
Debt Disclosure [Abstract]
Long-term debt	$ 77.4	$ 80.6	$ 240.4	$ 245.2
Short-term debt	1.2	1.0	2.0	2.3
Interest income	(0.5)	(0.2)	(0.8)	(1.0)
Interest capitalized	(1.2)	(1.6)	(4.8)	(4.7)
Interest expense, net	$ 76.9	$ 79.8	$ 236.8	$ 241.8