Segment Reporting - Net Revenues, Expenses and Total Assets by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019	Nov. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 1,383,444	$ 777,159	$ 3,588,507	$ 2,364,728
Non-interest expenses	1,020,043	694,084	2,816,860	2,063,930
Earnings before income taxes	363,401	83,075	771,647	300,798
Segment assets	46,660,448		46,660,448		$ 43,516,115
Investment Banking and Capital Markets
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	1,274,100	757,400	3,451,800	2,274,900
Non-interest expenses	992,700	671,200	2,706,000	1,991,000
Earnings before income taxes	281,400	86,200	745,800	283,900
Segment assets	43,552,000		43,552,000		40,565,800
Asset Management
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	109,300	19,800	136,700	89,800
Non-interest expenses	27,300	22,900	110,900	72,900
Earnings before income taxes	82,000	$ (3,100)	25,800	$ 16,900
Segment assets	$ 3,108,400		$ 3,108,400		$ 2,950,300