Debt - Additional Information (Detail) - USD ($)	1 Months Ended	6 Months Ended
	Mar. 31, 2015	Aug. 28, 2015	Feb. 28, 2015	Aug. 29, 2014
Debt Disclosure [Line Items]
Debt due within one year		$ 0	$ 0	$ 20,000,000
Letters of credit outstanding		26,400,000
Unamortized financing fees written off		1,800,000
Non Publicly Traded [Member] | Level 2 [Member]
Debt Disclosure [Line Items]
Fair value of traded debt		240,500,000	251,800,000	330,000,000
Carrying value of Corporation's non-publicly traded debt		$ 241,000,000	254,300,000	330,000,000
Term Loan Facility [Member]
Debt Disclosure [Line Items]
Interest on credit facility borrowings		2.70%
Voluntary prepayments on term loan facility	$ 65,000,000
Revolving Credit Facility [Member]
Debt Disclosure [Line Items]
Interest on credit facility borrowings		2.70%
Current borrowing capacity		$ 250,000,000
Publicly Traded [Member] | Level 1 [Member]
Debt Disclosure [Line Items]
Fair value of traded debt		234,100,000	238,200,000	240,300,000
Carrying value of Corporation's publicly traded debt		225,200,000	225,200,000	225,200,000
Accounts Receivable Facility [Member]
Debt Disclosure [Line Items]
Debt due within one year		0	$ 0	$ 0
Current borrowing capacity		$ 50,000,000