Long -Term Debt (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended
	Feb. 26, 2012	Feb. 27, 2011	Nov. 28, 2010	Feb. 26, 2012	Feb. 27, 2011	Feb. 26, 2012 Payment in Kind (PIK) Note [Member]	Feb. 26, 2012 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				$ 355.6	$ 291.7			$ 35.4	$ 342.7
Long-term debt interest rate	3.25%			3.25%					6.75%
Investment Holdings [Line Items]
Interest income	1.0	2.5		3.2	41.3	1.7	39.0
Long Term Debt Additional (Textual) [Abstract]
Reduction of net interest expense due to impact of interest rate swap contracts	2.2	3.1		7.7	11.4
Proceeds from termination of interest rate swap contract			$ 31.5