Retirement Benefits and Postemployment Benefits (Schedule of assumptions used to determine benefit obligations) (Details)	May 27, 2018	May 28, 2017
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	4.20%	4.08%
Rate of salary increases	4.27%	4.25%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	4.17%	3.92%
Rate of salary increases	0.00%	0.00%
Postemployment Benefit Plans [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	3.60%	2.87%
Rate of salary increases	4.44%	4.46%