Note 10 - Contingencies (Details Textual) $ in Millions		3 Months Ended	6 Months Ended	12 Months Ended		41 Months Ended
	Nov. 15, 2022 USD ($)	Aug. 28, 2022 USD ($)	Nov. 27, 2022 USD ($)	May 30, 2021 USD ($)	May 31, 2020 USD ($)	Nov. 27, 2022 USD ($)
Threshold Amount For Environmental Matters			$ 1.0
Lamb Weston Holdings Inc [Member]
Lessee, Operating Lease, Renewal Term (Year)			5 years			5 years
Briseno v. ConAgra Foods, Inc [Member]
Litigation Settlement, Amount Awarded to Other Party	$ 3.0
Beatrice [Member]
Accrual for Environmental Loss Contingencies, Ending Balance			$ 39.2			$ 39.2
Beatrice [Member] | Other Accrued Liabilities [Member]
Accrual for Environmental Loss Contingencies, Ending Balance			2.0			2.0
Beatrice [Member] | Other Noncurrent Liabilities [Member]
Accrual for Environmental Loss Contingencies, Ending Balance			37.2			37.2
MPCA [Member]
Accrued Environmental Loss Contingencies, Proposed Penalty Amount				$ 4.3	$ 1.8
Performance And Payment Guarantee [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted			75.0			75.0
Property Lease Guarantee [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted			$ 10.0			10.0
Lease Remaining Lease Terms (Year)			4 years
ILLINOIS
Loss Contingency Number Of Suits		1
CALIFORNIA | Beatrice [Member]
Litigation Settlement, Amount Awarded to Other Party		$ 101.7
Loss Contingency Settlement Agreement Terms Number Of Installments		7
Loss Contingency Accrual, Payments						61.0
CALIFORNIA | Beatrice [Member] | Other Accrued Liabilities [Member]
Loss Contingency Accrual, Ending Balance			$ 11.4			11.4
CALIFORNIA | Beatrice [Member] | Other Noncurrent Liabilities [Member]
Loss Contingency Accrual, Ending Balance			29.1			$ 29.1
CALIFORNIA | Beatrice [Member] | Maximum [Member]
Litigation Settlement Amount Of Guarantee			$ 15.0