PENSION AND POSTRETIREMENT BENEFITS - Components of Pension Benefit and Other Postretirement Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 26, 2017	Nov. 27, 2016	Nov. 26, 2017	Nov. 27, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit cost (benefit) — Company plans	$ 4.2	$ 2.8	$ 5.7	$ 5.1
Total cost (benefit)	(4.7)	(3.1)	(15.8)	(7.3)
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	13.2	15.9	25.9	32.6
Interest cost	27.7	29.9	55.9	59.9
Expected return on plan assets	(54.6)	(53.9)	(108.8)	(107.7)
Amortization of prior service cost	0.7	0.7	1.4	1.3
Recognized net actuarial loss	3.4	0.0	3.4	0.0
Special termination benefits	0.0	1.5	0.0	1.5
Curtailment loss	0.7	0.0	0.7	0.0
Benefit cost (benefit) — Company plans	(8.9)	(5.9)	(21.5)	(12.4)
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.0	0.1	0.0	0.1
Interest cost	0.9	1.0	1.8	2.1
Amortization of prior service cost	(0.8)	(1.6)	(1.6)	(3.3)
Recognized net actuarial loss	0.0	0.1	0.0	0.2
Total cost (benefit)	$ 0.1	$ (0.4)	$ 0.2	$ (0.9)