Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 28, 2011
Beatrice [Member]
Contingencies (Textuals) [Abstract]
Number of sites under environmental matters for which acquired company has a liability	37
Number of sites under environmental matters for which acquired company is making payments	34
Reserves for Beatrice environmental matters	$ 70.9
Maximum period expected for disbursements on environmental matters	19 years
Leases and other commercial obligations guarantee [Member]
Contingencies (Textuals) [Abstract]
Guarantee obligation under purchase agreement	12.9
Potato supply agreement guarantee [Member]
Contingencies (Textuals) [Abstract]
Amount of supplier loans effectively guaranteed	71.9
Onion supply agreement guarantee [Member]
Contingencies (Textuals) [Abstract]
Guarantee obligation under purchase agreement	$ 25.0
Term of loan under certain agreement, years	14 years