Allocation of Net Derivative Gains (Losses) from Economic Hedges of Forecasted Commodity Consumption and Foreign Currency Risk (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 26, 2012	Aug. 28, 2011
Operating Statistics [Line Items ]
Net derivative gains (losses) incurred	$ 120.2	$ (12.3)
Net derivative gains (losses) allocated to reporting segments	(10.0)	21.2
Net derivative gains (losses) recognized in general corporate expenses	130.2	(33.5)
Consumer Foods
Operating Statistics [Line Items ]
Net derivative gains (losses) allocated to reporting segments	(3.9)	18.3
Commercial Foods
Operating Statistics [Line Items ]
Net derivative gains (losses) allocated to reporting segments	$ (6.1)	$ 2.9