Commitments, Contingencies and Guarantees (Details Textual) (USD $)										3 Months Ended			3 Months Ended
	Feb. 29, 2012	Feb. 29, 2012 Jefferies Finance L P [Member]	Feb. 29, 2012 Jefferies Capital Partners LLC [Member]	Feb. 29, 2012 Other Investments [Member]	Feb. 29, 2012 Revolving credit facility [Member]	Feb. 29, 2012 Jefferies Employee Partners IV, LLC [Member]	Feb. 29, 2012 Jefferies Capital Partners IV LLC [Member]	Feb. 29, 2012 Jefferies Loan Core LLC [Member]	Feb. 23, 2011 Jefferies Loan Core LLC [Member]	Feb. 29, 2012 Jefferies Capital Partners V L.P. [Member]	Feb. 29, 2012 Jefferies Capital Partners IV L.P. [Member]	Feb. 29, 2012 Unrated [Member]	Feb. 29, 2012 USA Fund [Member]
Line of Credit Facility [Line Items]
Equity Commitments		$ 500,000,000	$ 5,900,000	$ 3,600,000			$ 3,100,000	$ 291,000,000	$ 600,000,000	$ 1,000,000	$ 45,900,000
Funded equity commitments	107,500,000						2,100,000	168,500,000			41,600,000
Unfunded equity commitments	392,500,000		4,900,000					115,000,000		56,400,000	5,300,000
Loan Commitments						54,000,000
Funded loan Commitments					79,900,000	45,200,000
Commitments funded										3,400,000			25,200,000
Aggregate investment	85,000,000									10,000,000			75,000,000
Unfunded Loan Commitments					420,100,000	8,800,000						428,900,000
Corporate Lending Commitments	641,900,000											517,400,000
Commitments Contingencies and Guarantees (Textual) [Abstract]
Corporate lending exposure carried at fair value included in financial instruments owned	215,300,000
Corporate lending exposure carried at fair value included in financial instruments sold	1,800,000
Loan commitments outstanding to clients	213,000,000
Fair value of loan commitments	1,800,000
Revolving credit facility	1,000,000,000
Fair value of derivative contracts approximated deemed to meet the definition of a guarantee	144,500,000
Fair value of mortgage-related commitments	$ 67,000,000