Investments - Jefferies LoanCore - Narrative (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2016	May 31, 2015	Nov. 30, 2015	Mar. 31, 2016	Feb. 29, 2016
Guarantee Obligations [Line Items]
Equity commitment	$ 600,000,000		$ 600,000,000
Jefferies LoanCore, LLC [Member]
Guarantee Obligations [Line Items]
Aggregate commitment	400,000,000		400,000,000				$ 600,000,000
Funded portion of equity commitment to subsidiary			78,300,000		$ 207,400,000
Equity commitment	$ 194,000,000		$ 194,000,000		291,000,000
Percentage of the Variable Interest Entity's (VIE) voting interest	48.50%		48.50%
Net earnings from equity method investment	$ 17,300,000	$ 16,500,000	$ 22,700,000	$ 36,500,000
Administrative services provided	47,000	48,000	95,000	96,000
Receivables under service agreement	$ 15,800		$ 15,800		$ 15,800
Placement fees earned		$ 200,000		$ 600,000
Canada Pension Plan Investment Board [Member] | Jefferies LoanCore, LLC [Member]
Guarantee Obligations [Line Items]
Ownership percentage by third party						24.00%