Long -Term Debt (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended
	Nov. 27, 2011	Nov. 28, 2010	Nov. 27, 2011	Nov. 28, 2010	Nov. 28, 2010 Payment in Kind (PIK) Note [Member]	Nov. 28, 2010 Payment in Kind (PIK) Note [Member]	Aug. 29, 2010 Lamb Weston BSW [Member]	Nov. 27, 2011 6.75% senior notes due [Member]
Long- Term Debt (Textual) [Abstract]
Repayment of debt			$ 348.1	$ 289.3			$ 35.4	$ 342.7
Long-term debt interest rate	3.25%		3.25%					6.75%
Investment Holdings [Line Items]
Interest income	0.9	19.4	2.2	38.8	18.8	37.3
Long Term Debt Additional (Textual) [Abstract]
Proceeds from termination of interest rate swap contract		31.5
Reduction of net interest expense due to impact of interest rate swap contracts	$ 2.4	$ 3.9	$ 5.5	$ 8.3