Retirement Benefits and Postemployment Benefits (Schedule of asset allocations for benefit plans) (Details)	May 30, 2021	May 31, 2020
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	100.00%	100.00%
Defined Benefit Pension Plans [Member] | United States Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	15.40%	19.70%
Defined Benefit Pension Plans [Member] | International Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	9.90%	11.00%
Defined Benefit Pension Plans [Member] | Private Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	9.30%	6.20%
Defined Benefit Pension Plans [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	54.60%	52.80%
Defined Benefit Pension Plans [Member] | Real asset investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	10.80%	10.30%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	100.00%	100.00%
Other Postretirement Benefit Plans [Member] | United States Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	28.00%	18.10%
Other Postretirement Benefit Plans [Member] | International Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	13.90%	9.80%
Other Postretirement Benefit Plans [Member] | Private Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	15.10%	4.40%
Other Postretirement Benefit Plans [Member] | Fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	43.00%	64.80%
Other Postretirement Benefit Plans [Member] | Real asset investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Weighted-Average Asset Allocations	0.00%	2.90%