Retirement Benefits and Postemployment Benefits (Schedule of amounts expected to be recognized in net periodic expense next year) (Details) $ in Millions	12 Months Ended
	May 28, 2017 USD ($)
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]
Amortization of losses	$ 176.9
Amortization of prior service costs (credits)	1.9
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]
Amortization of losses	0.8
Amortization of prior service costs (credits)	(5.4)
Postemployment Benefit Plans [Member]
Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]
Amortization of losses	0.6
Amortization of prior service costs (credits)	$ 0.8