Retirement Benefits - Additional Information (Detail) (USD $) In Millions, unless otherwise specified				9 Months Ended		3 Months Ended		9 Months Ended
	Nov. 23, 2012	Feb. 29, 2012	Nov. 25, 2011	Nov. 23, 2012 Domestic [Member] Profit Sharing [Member]	Nov. 25, 2011 Domestic [Member] Profit Sharing [Member]	Nov. 23, 2012 Domestic [Member] Defined Contribution Plan [Member]	Nov. 25, 2011 Domestic [Member] Defined Contribution Plan [Member]	Nov. 23, 2012 Domestic [Member] Defined Contribution Plan [Member]	Nov. 25, 2011 Domestic [Member] Defined Contribution Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Corporate contributions to the profit sharing plan				$ 3.9	$ 6.3	$ 2.3	$ 1.9	$ 4.9	$ 4.5
Liability for postretirement benefits other than pensions	28.6	24.8	29.9
Long-term liability for pension benefits	$ 75.7	$ 75.7	$ 59.8