Investments - Jefferies LoanCore - Narrative (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Feb. 28, 2013	Nov. 30, 2013	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2013	Feb. 23, 2011
Guarantee Obligations [Line Items]
Equity commitment			$ 600,000,000
Jefferies LoanCore, LLC [Member]
Guarantee Obligations [Line Items]
Aggregate commitment						$ 600,000,000
Funded portion of equity commitment to subsidiary			207,400,000	$ 200,900,000
Equity commitment			$ 291,000,000
Percentage of the Variable Interest Entity's (VIE) voting interest			48.50%
Net earnings from equity method investment			$ 79,000,000	38,700,000	$ 85,100,000
Reimbursed administrative services	$ 600,000	$ 500,000	200,000	100,000
Receivables under service agreement			15,800	8,900
Placement fees earned			$ 1,600,000	$ 1,600,000
Recognized net gains within principal transaction revenues	$ 200,000	$ 3,600,000