Retirement Benefits - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Nov. 25, 2016	Nov. 27, 2015	Nov. 25, 2016	Nov. 27, 2015	Feb. 29, 2016
Defined Contribution Plan Disclosure [Line Items]
Liability for postretirement benefits other than pensions	$ 19.9	$ 19.8	$ 19.9	$ 19.8	$ 17.8
Long-term liability for pension benefits	77.4	76.9	77.4	76.9	$ 80.2
Profit-Sharing and Benefit Plan 401 (k) [Member] | United States [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer's contributions to a defined contribution retirement plan	$ 3.4	$ 3.0	$ 11.9	$ 8.9