Related Party Transactions - Summary of Interest Income, Other Revenues and Investment Income to Private Equity Related Funds (Detail) - Equity Method Investee [Member] - Equity Investments in Jefferies Capital Partners Related Funds [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2017	May 31, 2016
Related Party Transaction [Line Items]
Other revenues and investment income (loss)	$ (8,122)	$ (5,064)	$ (9,420)	$ (7,712)
Service charges	$ 198	$ 207	$ 323	$ 336