Derivative Financial Instruments - Derivative Assets and Liabilities and Amounts Representing Right to Reclaim Cash Collateral Were Reflected in Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Nov. 25, 2012	May 27, 2012
Derivative Financial Instruments [Line Items]
Prepaid expenses and other current assets	$ 72.2	$ 58.7
Other accrued liabilities	$ 192.7	$ 215.4