PENSION AND POSTRETIREMENT BENEFITS (Costs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 25, 2013	Aug. 26, 2012
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.2	$ 0.1
Interest cost	2.4	2.5
Amortization of prior service cost	(1.8)	(2.1)
Recognized net actuarial loss	1.7	1.5
Total benefit cost	2.5	2.0
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	22.3	20.2
Interest cost	37.8	36.6
Expected return on plan assets	(63.2)	(52.3)
Amortization of prior service cost	0.9	0.8
Curtailment loss	0	0.8
Benefit cost - Company plans	(2.2)	6.1
Pension benefit cost - multi-employer plans	3.1	2.1
Total benefit cost	$ 0.9	$ 8.2