PENSION AND POSTRETIREMENT BENEFITS - Components of Pension Benefit and Other Postretirement Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 28, 2016	Aug. 30, 2015
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 16.7	$ 23.8
Interest cost	30.0	41.0
Expected return on plan assets	(53.8)	(66.9)
Amortization of prior service cost	0.6	0.7
Benefit cost — Company plans	(6.5)	(1.4)
Pension benefit cost — multi-employer plans	2.3	2.3
Total benefit cost (benefit)	(4.2)	0.9
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.0	0.1
Interest cost	1.1	2.0
Amortization of prior service cost	(1.7)	(2.0)
Recognized net actuarial loss	0.1	0.0
Total benefit cost (benefit)	$ (0.5)	$ 0.1