Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Feb. 22, 2009	Feb. 26, 2012 Hogs
Additional Contingencies (Textual) [Abstract]
Maximum period of guarantee under leases and other commercial obligations guarantee agreement		4
Minimum quantity of hogs to be purchased under hog purchase agreement through 2014		1,200,000
Guaranteed period to third parties for income tax credits over their statutory lives		7 years
Face value of federal income tax credits		$ 21.2
Dispute coverage charge with insurance carrier	24.8
Term of loan under certain agreement years		11 years
Loan purchase under agreement		41
Loan principal and accrued interest		40
Recognized charges in connection with peanut butter matter		7.5
Beatrice [Member]
Contingencies (Textual) [Abstract]
Number of sites under environmental matters for which acquired company has a liability		35
Number of sites under environmental matters for which acquired company is making payments		32
Reserves for Beatrice environmental matters		70.4
Maximum period expected for disbursements on environmental matters		18 years
Leases and other commercial obligations guarantee [Member]
Contingencies (Textual) [Abstract]
Guarantee obligation under purchase agreement		11.5
Potato supply agreement guarantee [Member]
Contingencies (Textual) [Abstract]
Amount of supplier loans effectively guaranteed		16.5
Onion supply agreement guarantee [Member]
Contingencies (Textual) [Abstract]
Guarantee obligation under purchase agreement		$ 25.0