SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Income Tax Expense (Benefit)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 22, 2015	Feb. 23, 2014	Feb. 22, 2015	Feb. 23, 2014
Accounting Policies [Abstract]
Net derivative adjustment	$ 0	$ 15.6	$ (0.2)	$ 38.9
Unrealized gains (losses) on available-for-sale securities	0.2	(0.1)	0.3	0.1
Pension and postretirement healthcare liabilities	(0.1)	0.2	0.7	0.9
Income tax expense	$ 0.1	$ 15.7	$ 0.8	$ 39.9