Retirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 24, 2019	Feb. 25, 2018	Feb. 24, 2019	Feb. 25, 2018
Defined Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	$ 2.4	$ 2.1	$ 7.0	$ 6.4
Expected return on plan assets	(2.8)	(3.0)	(8.4)	(9.0)
Recognized net actuarial loss	0.6	0.7	1.9	2.1
Net periodic benefit (credit) cost	0.2	(0.2)	0.5	(0.5)
Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.0	0.0	0.0	0.1
Interest cost	0.2	0.2	0.6	0.5
Amortization of unrecognized prior service credit	(1.2)	(1.2)	(3.6)	(3.6)
Recognized net actuarial loss	0.4	0.4	1.2	1.3
Net periodic benefit (credit) cost	$ (0.6)	$ (0.6)	$ (1.8)	$ (1.7)