Debt - Additional Information (Detail) (USD $)	May 31, 2013	Feb. 28, 2013	May 25, 2012
Debt Disclosure [Line Items]
Carrying value of Corporations traded debt	$ 260,281,000	$ 286,381,000	$ 225,181,000
Letters of credit outstanding	27,500,000
Non Publicly Traded [Member]
Debt Disclosure [Line Items]
Carrying value of Corporations traded debt	35,100,000	61,200,000
Fair value of Corporations publicly and non-publicly traded debt	35,100,000	61,200,000
Publicly Traded [Member]
Debt Disclosure [Line Items]
Carrying value of Corporations traded debt	225,200,000	225,200,000	225,200,000
Fair value of Corporations publicly and non-publicly traded debt	227,400,000	233,600,000	229,100,000
Credit Agreement [Member]
Debt Disclosure [Line Items]
Current borrowing capacity	400,000,000
Credit Agreement [Member] | Non Publicly Traded [Member]
Debt Disclosure [Line Items]
Carrying value of Corporations traded debt	35,100,000	61,200,000	0
Accounts receivable facility [Member]
Debt Disclosure [Line Items]
Available financing of receivables purchase agreement	$ 50,000,000