Jefferies Finance LLC (Details Textuals] (USD $)	3 Months Ended		8 Months Ended	9 Months Ended				3 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2010	Aug. 31, 2011	Nov. 30, 2011	Feb. 28, 2011	Nov. 30, 2010	Feb. 28, 2011 Maximum [Member]	Feb. 28, 2011 Minimum [Member]
Guarantor Obligations [Line Items]
Total commitment under revolving line of credit								$ 500,000,000	$ 150,000,000
Jefferies Finance LLC (Textuals) [Abstract]
Increase in equity commitment to JFIN						250,000,000
Total committed equity capitalization of JFIN						1,000,000,000
Funded portion of equity commitment to subsidiary	107,500,000			107,500,000
Aggregate commitment	500,000,000			500,000,000
Unfunded portion of equity commitment to subsidiary	392,500,000			392,500,000
Line of credit facility commitment under joint venture						1,000,000,000
Additional Funded portion of equity commitment to subsidiary	194,700,000			194,700,000
Additional Aggregate commitment	500,000,000			500,000,000
Maturity date description				Scheduled to mature on March 1, 2014 with an automatic extension subject to a 60 day termination notice by either party
Amount outstanding under the revolving line of credit	0			0	0		0
Net earnings of JFIN	10,500,000	18,000,000	48,200,000	69,300,000
Payment for the purchase of participation certificates in loans originated by JFIN				477,200,000
Fees paid to JFIN related to originations of loans by JFIN	16,600,000	8,000,000	19,000,000	52,000,000
Fees earned to JFIN related to originations of loans by JFIN	$ 2,900,000	$ 1,700,000	$ 12,200,000	$ 9,300,000