Retirement Benefits and Postemployment Benefits (Schedule of amounts recognized in AOCI) (Details) - USD ($) $ in Millions	May 28, 2017	May 29, 2016
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	$ (1,645.4)	$ (1,958.2)
Prior service (costs) credits	19.5	11.9
Amounts recorded in accumulated other comprehensive loss	(1,625.9)	(1,946.3)
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	(1,621.4)	(1,886.0)
Prior service (costs) credits	(3.9)	(6.8)
Amounts recorded in accumulated other comprehensive loss	(1,625.3)	(1,892.8)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	(14.5)	(57.6)
Prior service (costs) credits	22.8	19.9
Amounts recorded in accumulated other comprehensive loss	8.3	(37.7)
Postemployment Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	(9.5)	(14.6)
Prior service (costs) credits	0.6	(1.2)
Amounts recorded in accumulated other comprehensive loss	$ (8.9)	$ (15.8)