Investments - Summary of Selected Financial Information for Jefferies Finance (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 28, 2021	Feb. 29, 2020	Nov. 30, 2020
Schedule of Equity Method Investments [Line Items]
Net earnings	$ 493,865	$ 171,365
Jefferies Finance, LLC
Schedule of Equity Method Investments [Line Items]
Interest income	300	800
Unfunded commitment fees	300	300
Our total equity balance	635,200		$ 604,600
Origination and syndication fee revenues	70,300	37,700
Origination fee expenses	12,300	5,600
CLO placement fee revenues	2,400	400
Underwriting fees	500	300
Service fees	31,500	25,200
Jefferies Finance, LLC | Equity method investment, nonconsolidated investee or group of investees
Schedule of Equity Method Investments [Line Items]
Net earnings	$ 61,300	$ 20,700