Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	May 27, 2012	May 29, 2011	Feb. 22, 2009	May 27, 2012 Hogs	May 31, 2012
Contingencies (Textual) [Abstract]
Reserves for Beatrice environmental matters	$ 71.2	$ 70.2		$ 71.2
Additional Contingencies (Textual) [Abstract]
Maximum period of guarantee under leases and other commercial obligations guarantee agreement				4 years
Minimum quantity of hogs to be purchased under hog purchase agreement through 2013				1,200,000
Face value of federal income tax credits	21.2			21.2
Dispute coverage charge with insurance carrier			24.8
Loan principal and accrued interest	40			40
Term of loan under certain agreement years				11 years
Loan purchase under agreement	41			41
Recognized charges in connection with peanut butter matters				17.5
Amount receive on opinion related to defense costs		11.8
Claim amount for disputed coverage	25
Amount of compensatory damage between company and Westside					78
Amount of punitive damage against company					100
Accrued deductible amount					3
Beatrice [Member]
Contingencies (Textual) [Abstract]
Number of sites under environmental matters for which acquired company has a liability				36
Number of sites under environmental matters for which acquired company is making payments				32
Reserves for Beatrice environmental matters	70.0			70.0
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	10.9			10.9
Potato supply agreement guarantee [Member]
Contingencies (Textual) [Abstract]
Amount of supplier loans effectively guaranteed	43.6			43.6
Onion supply agreement guarantee [Member]
Contingencies (Textual) [Abstract]
Guarantee obligation under purchase agreement	$ 25.0			$ 25.0