Retirement Benefits and Postemployment Benefits (Schedule of assumptions used to determine benefit obligations) (Details)	May 31, 2020	May 26, 2019
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	3.20%	3.91%
Rate of salary increases	4.44%	4.17%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	3.02%	3.79%
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	1.85%	3.10%
Rate of salary increases	4.51%	4.47%