Retirement Benefits - Additional Information (Detail) (USD $) In Millions, unless otherwise specified				3 Months Ended
	May 31, 2013	Feb. 28, 2013	May 25, 2012	May 31, 2013 Profit-sharing plan [Member]	May 31, 2012 Profit-sharing plan [Member]	May 31, 2013 Defined contribution plans [Member] Domestic [Member]	May 31, 2012 Defined contribution plans [Member] Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Corporate contributions to the profit-sharing plan				$ 4.0	$ 3.0	$ 1.3	$ 1.3
Liability for postretirement benefits other than pensions	16.8	15.7	26.2
Long-term liability for pension benefits	$ 81.2	$ 81.4	$ 75.6