Investments - Jefferies Finance - Narrative (Detail) - USD ($)	3 Months Ended		6 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014	Nov. 30, 2014
Guarantee Obligations [Line Items]
Equity commitments to JFIN	$ 600,000,000		$ 600,000,000
Total committed equity capitalization of JIFN	1,200,000,000		1,200,000,000
Funded portion of equity commitment to subsidiary	486,500,000		486,500,000
Unfunded portion of equity commitment to subsidiary	113,500,000		$ 113,500,000
Extension period			1 year
Termination notice period			60 days
Committed line of credit facility amount	1,000,000,000		$ 1,000,000,000
Maturity date			Mar. 01, 2016
Funded portion of loan commitment	0		$ 0		$ 0
Loan commitment	350,000,000		350,000,000
Interest income	59,000	$ 600,000	500,000	$ 1,100,000
Unfunded commitment fees	400,000	400,000	800,000	1,100,000
Net underwriting fees paid by JFIN related to originations of loans by JFIN	39,900,000	38,800,000	55,500,000	86,400,000
Fees paid to JFIN related to origination of loans by JFIN	900,000	3,400,000	1,600,000	7,700,000
Placement fees	404,262,000	331,149,000	676,257,000	745,469,000
Revenue in Connection of Execution of JFIN CLO	173,508,000	167,378,000	340,430,000	329,441,000
Underwriting fees	1,300,000	4,200,000
Committed Advances [Member]
Guarantee Obligations [Line Items]
Committed line of credit facility amount	700,000,000		700,000,000
Discretionary Advances [Member]
Guarantee Obligations [Line Items]
Committed line of credit facility amount	300,000,000		300,000,000
Jefferies Finance, LLC [Member]
Guarantee Obligations [Line Items]
Net income earnings	41,200,000	29,300,000	62,300,000	58,500,000
Placement fees	3,100,000		3,100,000
Revenue in Connection of Execution of JFIN CLO		1,800,000		2,200,000
Administrative services provided	7,100,000	$ 7,000,000	34,900,000	$ 28,700,000
Receivables under service agreement	$ 57,100,000		$ 57,100,000		$ 41,500,000