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, 2019	Sep. 30, 2018	Aug. 31, 2019	Sep. 30, 2018
Trading Assets
Financial Instruments [Line Items]
Loans and other receivables	$ 2,040	$ 14,002	$ (5,458)	$ 7,495
Trading Liabilities
Financial Instruments [Line Items]
Loans	0	(2,708)	0	(2,467)
Loan commitments	(443)	(1,695)	(1,200)	(1,964)
Long-term debt
Financial Instruments [Line Items]
Changes in instrument specific credit risk	6,922	1,401	34,414	19,986
Other changes in fair value	$ (46,003)	$ (6,842)	$ (93,311)	$ 33,626