PENSION AND POSTRETIREMENT BENEFITS - Schedule of Other Changes in Plan Assets and Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	May 27, 2018	May 28, 2017	May 29, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net amount recognized	$ 113.0	$ 135.0	$ (32.5)
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial gain	120.0	183.1
Amendments	(0.6)	(5.5)
Amortization of prior service cost (benefit)	2.9	2.9
Settlement and curtailment loss	2.0	13.8
Recognized net actuarial loss	3.4	1.2
Net amount recognized	127.7	195.5
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial gain	16.8	32.4
Amendments	17.2	(0.4)
Amortization of prior service cost (benefit)	(3.4)	(6.6)
Settlement and curtailment loss	0.0	0.0
Recognized net actuarial loss	0.0	0.5
Net amount recognized	$ 30.6	$ 25.9