Investments - Summary of Selected Financial Information for Jefferies Finance (Detail) (Jefferies Finance, LLC [Member], USD $)	Feb. 28, 2015	Nov. 30, 2014
Jefferies Finance, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Total assets	$ 5,983,800,000	$ 5,954,000,000
Total liabilities	4,970,400,000	4,961,700,000
Total equity	1,013,400,000	992,300,000
Our total equity balance	$ 506,700,000	$ 496,000,000