Financial Instruments, Risk Management Activities, and Fair Values (Schedule of cashflow hedge in AOCI) (Details) - USD ($) $ in Millions	May 27, 2018	May 28, 2017
Derivative [Line Items]
After-tax gain (loss) in AOCI related to hedge derivatives	$ (32.1)	$ 1.5
Interest Rate Contracts [Member]
Derivative [Line Items]
After-tax gain (loss) in AOCI related to hedge derivatives	(39.6)
Foreign Exchange Contracts [Member]
Derivative [Line Items]
After-tax gain (loss) in AOCI related to hedge derivatives	$ 7.5