Deferred Costs - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Nov. 23, 2012	Feb. 29, 2012	Nov. 25, 2011
Deferred Costs and Future Payment Commitment for Retail Supply Agreements [Line Items]
Allowance for deferred costs related to supply agreements	$ 7.8	$ 10.0	$ 10.0