Short-Term Borrowings (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Apr. 23, 2015	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2015	Aug. 31, 2014	Nov. 30, 2014	Aug. 26, 2011
Short-term Debt [Line Items]
Short-term borrowings		$ 12,000,000		$ 12,000,000		$ 12,000,000
Interest rate on short-term borrowings outstanding		0.68%		0.68%
Average daily short-term borrowings		$ 18,500,000	$ 31,300,000	$ 44,900,000	$ 87,900,000
Revolving credit facility							$ 950,000,000.0
Line of Credit [Member] | Intraday Credit Facility [Member]
Short-term Debt [Line Items]
Revolving credit facility	$ 500,000,000.0
Debt term	6 months
Extension term	6 months
Line of Credit [Member] | Intraday Credit Facility [Member] | Prime Rate [Member]
Short-term Debt [Line Items]
Basis spread on variable rate	0.50%