Intangible Assets, Net and Goodwill (Schedule of Intangible Assets, Net And Goodwill) (Details) - USD ($) $ in Thousands	Aug. 31, 2020	Nov. 30, 2019
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Amortizable intangibles	$ 171,117	$ 182,954
Goodwill	1,743,425	1,739,980
Total intangible assets, net and goodwill	1,914,542	1,922,934
Real estate
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	36,711	36,711
Other operations
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	3,459	3,459
Investment Banking and Capital Markets
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	1,560,255	1,556,810
Asset Management
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	143,000	143,000
Historical Investment Banking, Capital Markets and Asset Management Segment
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill		1,699,800
Customer and other relationships
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Amortizable intangibles	53,396	59,575
Intangible assets, accumulated amortization	117,609	111,060
Trademarks and tradenames
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Amortizable intangibles	101,207	103,790
Intangible assets, accumulated amortization	27,673	24,800
Other
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Amortizable intangibles	8,640	11,316
Intangible assets, accumulated amortization	8,042	5,366
Exchange and clearing organization membership interests and registrations
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite lived intangibles	$ 7,874	$ 8,273