Retirement Benefits and Postemployment Benefits (Schedule of estimated benefit payments) (Details) $ in Millions	May 29, 2016 USD ($)
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
Medicare Subsidy Receipts, Next Twelve Months	$ 4.8
Medicare Subsidy Receipts, Year Two	5.2
Medicare Subsidy Receipts, Year Three	5.6
Medicare Subsidy Receipts, Year Four	5.2
Medicare Subsidy Receipts, Year Five	4.2
Medicare Subsidy Receipts, Five Fiscal Years Thereafter	23.2
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	277.7
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	287.9
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	297.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	306.8
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	316.4
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	1,731.5
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	61.3
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	65.5
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	67.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	68.3
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	69.2
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	355.2
Postemployment Benefit Plans [Member]
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	22.1
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	20.6
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	19.2
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	17.8
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	17.0
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 75.6