Investments - Summary of Selected Financial Information for Jefferies Finance (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017	Nov. 30, 2017
Schedule of Equity Method Investments [Line Items]
CLO placement fee revenues	$ 155,539	$ 139,082	$ 461,545	$ 437,547
Jefferies Finance, LLC
Schedule of Equity Method Investments [Line Items]
Interest income	0	200	1,200	2,500
Unfunded commitment fees	300	300	800	800
Our total equity balance	706,500		706,500		$ 636,200
Net earnings	38,000	40,800	140,700	133,500
Origination and syndication fee revenues	71,100	104,200	282,100	243,500
Origination fee expenses	12,100	0	45,500	2,500
CLO placement fee revenues	400	800	3,100	4,700
Derivative losses	(300)	(200)	(900)	(600)
Underwriting fees	0	0	300	0
Service fees	$ 13,300	$ 7,900	$ 48,300	$ 37,400