Fair Value Disclosures (Summary of Gains (Losses) Due to Changes in Instrument Specific Credit Risk on Loans, Other Receivables and Debt Instruments Measured at Fair Value Under Fair Value Option) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans and other receivables	$ 1,704	$ 2,040	$ (11,256)	$ (5,458)
Loans	367	0	(610)	0
Loan commitments	1,875	(443)	464	(1,200)
Changes in instrument specific credit risk	(656)	0	898	(493)
Short-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument specific credit risk	(23)	0	(92)	0
Other changes in fair value	(1,115)	0	(959)	0
Other secured financings
Fair Value, Option, Quantitative Disclosures [Line Items]
Other changes in fair value	617	0	617	0
Long-term debt
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument specific credit risk	(177,801)	6,922	49,369	34,414
Other changes in fair value	$ (9,943)	$ (46,003)	$ (78,567)	$ (93,311)