Leases (Schedule of maturities of operating lease liabilities - Present value of lease liabilities) (Details) [Table] - USD ($) $ in Millions	May 31, 2020	May 26, 2019
Operating Lease Liabilities Payments Due [Abstract]
Less: Interest	$ (33.5)
Present value of lease liabilities	379.0
Total lease payments	$ 412.5
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Finance Lease Liabilities Payments Due [Abstract]
Less: Interest	$ 0.0
Finance Lease Liability	0.2
Total finance lease payments	$ 0.2