Investments - Jefferies LoanCore - Narrative (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Nov. 30, 2015	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	184,700,000		$ 207,400,000
Equity commitment	$ 291,000,000
Percentage of the Variable Interest Entity's (VIE) voting interest	48.50%
Net earnings from equity method investment	$ 5,400,000	$ 20,000,000
Administrative services provided	47,400	47,400
Receivables under service agreement	$ 15,800		$ 15,800
Placement fees earned		$ 400,000