Investments - Summary of Selected Financial Information for Jefferies Finance (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2017	May 31, 2016	Nov. 30, 2016
Schedule of Equity Method Investments [Line Items]
CLO placement fee revenues	$ 152,643	$ 146,157	$ 298,465	$ 301,981
Derivative gains (losses)	351,863	253,046	759,884	483,976
Jefferies Finance, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Interest income	1,200	0	2,300	0
Unfunded commitment fees	200	300	500	600
Our total equity balance	516,900		516,900		$ 470,500
Net earnings	50,700	33,200	92,700	77,800
Origination and syndication fee revenues	73,100	3,700	139,300	23,100
Origination fee expenses	400	1,600	2,500	1,600
CLO placement fee revenues	1,200	0	3,900	0
Derivative gains (losses)	(300)	0	(400)	1,300
Service fees	$ 9,300	$ 7,500	$ 29,500	$ 28,600