Investments - Jefferies Finance - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Nov. 30, 2015
Guarantee Obligations [Line Items]
Equity commitments to JFIN	$ 600,000
Total committed equity capitalization of JIFN	1,200,000
Funded portion of equity commitment to subsidiary	474,400
Unfunded portion of equity commitment to subsidiary	$ 125,600
Extension period	1 year
Termination notice period	60 days
Maturity date	Mar. 01, 2016
Funded portion of loan commitment	$ 0		$ 19,300
Loan commitment	250,000		250,000
Interest income	2	$ 500
Unfunded commitment fees	300	400
Net underwriting fees paid by JFIN related to originations of loans by JFIN	19,400	15,600
Fees paid to JFIN related to origination of loans by JFIN		700
Revenue in Connection of Execution of JFIN CLO	155,824	166,922
Jefferies Finance, LLC [Member]
Guarantee Obligations [Line Items]
Net income (loss) in earnings	(45,900)	21,100
Revenue in Connection of Execution of JFIN CLO	1,400
Administrative services provided	21,100	$ 27,800
Receivables under service agreement	6,000		$ 7,800
Discretionary Advances [Member]
Guarantee Obligations [Line Items]
Committed line of credit facility amount	1,000,000
Committed Advances [Member]
Guarantee Obligations [Line Items]
Committed line of credit facility amount	$ 500,000