Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2020	May 26, 2019	May 27, 2018
Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, contribution by employer to fully fund benefit obligation	$ 12.7
Defined benefit pension plans and postretirement benefit plans funding	13.2	$ 0.4	$ 60.8
Pension settlement charge	145.5	0.0	0.0
Benefits paid	(271.8)
Benefits paid	$ (272.2)	$ (17.8)
Expected long-term rate of return on plan assets (percentage)	0.00%	4.25%
Amortization of net actuarial gain (loss)	$ 0.1
Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plans and postretirement benefit plans funding	1.3	$ 1.3	1.2
Pension settlement charge	0.0	0.0	$ 0.0
Benefits paid	(1.3)	$ (1.3)
Expected employer contribution to the benefit plans	1.3
Amortization of net actuarial gain (loss)	1.3
Maximum | Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Expected employer contribution to the benefit plans	$ 0.4