Short-Term Borrowings (Detail) - USD ($)	3 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Nov. 30, 2017
Short-term Debt [Line Items]
Short-term borrowings	$ 468,046,000		$ 436,215,000
Interest rate on short-term borrowings outstanding	2.28%
Average daily short-term borrowings	$ 488,100,000	$ 448,100,000
Floating rate puttable notes
Short-term Debt [Line Items]
Short-term borrowings	111,034,000		108,240,000
Equity-linked notes
Short-term Debt [Line Items]
Short-term borrowings	0		23,324,000
Equity-Linked Notes Matured On December 7, 2017
Short-term Debt [Line Items]
Debt principal amount			23,300,000
Bank loans
Short-term Debt [Line Items]
Short-term borrowings	357,012,000		$ 304,651,000
Line of credit | Intraday Credit Facility
Short-term Debt [Line Items]
Credit facility maximum borrowing capacity	$ 150,000,000
Line of credit | Intraday Credit Facility | Federal funds effective rate
Short-term Debt [Line Items]
Basis spread on variable rate	0.50%