Fair Value Disclosures - Summary of Gains (Losses) Due to Changes in Instrument Specific Credit Risk for Loans and Other Receivables and Loan Commitments Measured at Fair Value under Fair Value Option (Detail) - USD ($) $ in Thousands	3 Months Ended
	Feb. 28, 2019	Feb. 28, 2018
Financial instruments owned:
Loans and other receivables	$ (7,335)	$ 2,628
Long-term debt
Financial instruments sold, not yet purchased and Long-term debt
Changes in instrument specific credit risk	23,483	(16,202)
Other changes in fair value	(10,643)	41,154
Loans
Financial instruments sold, not yet purchased and Long-term debt
Changes in instrument specific credit risk	0	250
Loan commitments
Financial instruments sold, not yet purchased and Long-term debt
Changes in instrument specific credit risk	$ 79	$ (129)