Investments - Summary of Selected Financial Information for Jefferies Finance (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017	Nov. 30, 2017
Schedule of Equity Method Investments [Line Items]
CLO placement fee revenues	$ 158,104	$ 152,643	$ 306,006	$ 298,465
Jefferies Finance, LLC
Schedule of Equity Method Investments [Line Items]
Interest income	400	1,200	1,200	2,300
Unfunded commitment fees	300	200	500	500
Our total equity balance	687,500		687,500		$ 636,200
Net earnings	60,200	50,700	102,700	92,700
Origination and syndication fee revenues	109,600	73,100	211,000	139,300
Origination fee expenses	14,900	400	33,400	2,500
CLO placement fee revenues	2,400	1,200	2,700	3,900
Derivative losses	(300)	(300)	(600)	(400)
Underwriting fees	0	0	300	0
Service fees	$ 8,900	$ 9,300	$ 35,000	$ 29,500